Ebook AKOTrace

INDEX
INTRODUCTION: Optimization is the key ............................................................. 3
A small but key investment for any CSP plant ..................................................... 4
Avoiding Poorly Performing CSP plants ................................................................ 5
CSP plants: When temperature regulation fails ................................................... 6
CSP Plants: Poor planning, poor performance ..................................................... 7
4+1 key factors to consider in an electrical heat tracing system ......................... 8
The structure of an optimal heat tracing solution (I) ........................................... 9
The structure of an optimal heat tracing solution (II) ........................................ 10
Optimal installation of the Electrical Heat Tracing System (I) ........................... 12
Optimal installation of the Electrical Heat Tracing System (II) .......................... 14
AKOTRACE® Solution for HTF areas .................................................................... 15
AKOTRACE® Solution for Molten Salt areas ....................................................... 16
PROTrace®: Control and power cabinets for electrical trace circuits (I) ............ 17
PROTrace®: Control and power cabinets for electrical trace circuits (II) ........... 18
PROTrace®: Control and power cabinets for electrical trace circuits (III) .......... 19
PROTrace®: Control and power cabinets for electrical trace circuits (IV) ......... 20
DUOControl Trace: The brain inside AKO´s ProTrace® cabinets (I) ................... 21
DUOControl Trace: The brain inside ProTrace® cabinets (II) ............................. 22
AKONet Trace, AKO´s control software for EHT systems ................................... 23
DUOVision Touch Trace: Designed for small EHT systems ................................ 24
AKO´s MI heating cable ...................................................................................... 25
Temperature Sensors I ....................................................................................... 26
Temperature Sensors II ...................................................................................... 27
AKONet Trace: Alarm Management (I) .............................................................. 28
AKONet Trace: Alarm Management (II) ............................................................. 29
2

Optimization is the key
Optimizing the performance of a concentration solar power (CSP) plant is
essential.
Weather a plant uses parabolic cylinder
technology or a concentrating solar
power tower, managing the process of
transforming sun energy into electricity is
a tricky task. That´s when an optimum
electrical heat-tracing system comes
into place, especially in thermal storage
plants. We know that there are other
components that play an important role
in any plant, but this particular one is
crucial because its malfunction can lead to major problems with costly solutions.
The transformation of energy is possible thanks to the thermal transfer between
heat carrier fluids such as steam, thermal oils or molten salts.
At the end, is the thermal oil, in the case of parabolic cylinder´s plants, and
molten salts, in solar power tower plants, that by ex-changing heat generate
the necessary steam to drive the turbine that makes electricity.
The main function of an electrical heat tracing system is to maintain the right
temperature throughout the process, avoiding solidification of the fluids,
whether they are oils or salts.
If this crucial component fails, the plant could incur into unexpected expenses
or, even worst, it can result in having the plant out of commission for a period of
time.
Even with optimum planning, there are always some unforeseen problems that
can arise during installation, execution and maintenance of any heat tracing
system, and each one of them could have a different impact on the plant.
In following posts we´ll try to analyze some of the most common risks assessed
in economic terms.
3

A small but key investment for any CSP
plant
An electrical heat tracing system represents
just 0,5% of the total investment in a CSP
project, but its failure could lead to major
losses that could affect the overall
profitability ratio of the plant. Therefore,
optimizing the performance of the electrical
heat tracing system is critical to be considered
as market leaders. There are, though,
some factors that could compromise this
goal. How?
Let´s first make a short list of economic indicators that can determine in any
way the outcome of the expected net production of a solar plant:
� Capital expenditure (CAPEX).
� Days of production.
� Production efficiency (a combination between performance and operational
/production costs).
And now let´s make a second list, this time of what happens when the electrical
heat tracing system is not managed properly or fails unexpectedly:
� It raises the plant´s expenses.
� It can reduce the performance of the main electrical production systems.
� The amount of self consumed electricity of the plant could raise unexpectedly.
� If the breakdown causes a plant stoppage, it would inevitable translate
into less production days and major reparation costs.
All these factors are directly related to the first list: They all alter the initial plan
in terms of money and time, and all of the sudden, this 0,5% becomes more
crucial.
We have been talking economics, but in our next post we´ll take a look at the
technical challenges that a plant can face when the electrical heat tracing
system does not perform as expected.
4

Avoiding Poorly Performing CSP plants
The scenarios that could lead a CSP plant to perform poorly are diverse.
All the components of the plant can be in
trouble at some point. There are mistakes
of a more technical nature, but failures
could also emerge from planning to execution;
from maintenance to supervision.
Undoubtedly, the electrical heat tracing
system plays a key role in the overall performance
of the plant. It goes across the
power block (the Thermal Energy Storage, The Heat TransferFluid and the
Balance of Plant systems) therefore, from a technical stand of point we are
talking about a wide range of possible breakdowns.
Let´s enumerate some of them: (1) Unplanned stoppage when heat carrier
fluids get frozen; (2) Loss of performance due to poor temperature regulation of
the processes (HTF, TES, and BOP); (3) Unsuitable requirements (when the plant
is already operational).
There is a saying that goes…”Your lack of planning is not my emergency¨. Well,
unfortunately in CSP plants, lack of planning is everybody´s emergency. It
represents another costly mistake that could prevent a CSP plant to perform
optimally. Some other failures of that nature:
� Unexpected investments and/or interventions when the plant is fully
operational.
� Being behind schedule without enough time to react (taking into account
that the tracing system is one of the last components to be installed).
� Lack of background knowledge to ensure the performance of the plant.
� More investment costs (when the engineering part of the process hasn´t
been planned properly).
Some of these failures could be managed, unexpected problems show up in any
project, but some of them could be avoided. What we´ll try to analyze in
following posts is why CSP plants and their electrical heat tracing systems face
these issues in the first place, and then come up with efficient solutions and
alternatives.
5

CSP plants:
When temperature regulation fails
We continue analyzing ways of avoiding
poor performance in CSP plants and their
electrical heat tracing systems, focusing
today on breakdowns caused when
temperature is not regulated properly.
One of the worst fears for anyone involved
in a CSP project is having the plant out of
commission, even for a short period of
time. But unwanted plant stoppages do
happen and bad temperature regulation can be one of the causes leading to this
undesirable outcome. Let´s take a look at what happens when either water or
heat transfer fluids freeze. This scenario could present itself when:
� The engineering team lacks thermodynamic expertise, that is, do not have
enough experience in Thermal Cycles inside CSP plants, undersizing the
whole project thus causing system failing.
� When the system control solution is weak preventing the staff from receiving
valuable, real time information to help them detect and manage on a
timely manner a wide range of possible system´s breakdowns
� Faulty installation due to lacking of know-how to notice details that are
key to the system and a deficient quality control supervision
Such shortcomings could cause the plant to be out of commission for one day
which translates into $267,000 in losses. There is more: The additional costs of
repairing the tracing system and/or damaged equipment could add up to $8.2
million.
Another issue that could arise regarding temperature supervision is when the
established system for process temperature regulation (HTC, TES, BOP) is not
efficient, resulting in a significant loss of performance. This happens, among
other factors already mentioned in the list above, when the implemented
regulation solution is weak. This particular mistake could cause a 5% increase in
energy self consumption of the electrical heat tracing (for each degree increase
in temperature in the system´s performance).
On our next post, we will analyze what happens when the team in charge of a
CSP plant does a poor job planning the project.
*Data referring to CSP plants using parabolic cylinder technology with a molten salt storage for
up to 7, 5 hours.
6

CSP Plants:
Poor planning, poor performance
It´s only logical: if you don´t plan correctly, you
don´t get the expected results. Breakdowns of a
technical nature are, sometimes, unavoidable. Bad
planning is a human error, and such kind of
mistakes seem easier to solve, don´t they? Yes,
but let´s be honest, in a CSP project with budget
and time concerns and limitations some of the
simplest principles that we all know “in theory”
are rapidly overlooked. All of the sudden solving
this issue gets complicated.
A management team with no experience or that
doesn´t handle properly a CSP project contributes
to:
� Applying an ineffective supervision and quality control solution for the
plant
� A poor execution of an already poor plan
If these problems originated because of time related pressures we have some
bad news: It turns out that to solve them would take even more precious time.
We are talking about delays in the starting of the plant, and since the electrical
tracing system is one of the latest components of the plant to be installed, the
team finds itself in a position with not enough leeway to react.
As in any other business, loss of time means loss of money. In this case we are
talking about:
� The plant could be out of commission for one day which translates into
$267,000 in losses.
� A 20% capital budget deviation, that is $410,000
As we stated at the beginning, poor planning is probably one of the most
complicated issues to handle when analyzing critical risks in an inadequate
electrical heat tracing solution, but it is not impossible to solve. If you want to
learn about how to deal directly with these and other challenges related to the
development of a CSP project, we invite you to get familiar with our Akotrace®
solution.
7

4+1 key factors to consider in an
electrical heat tracing system
In this blog we have already stated how critical
an electrical heat tracing system is in the
temperature control process of any CSP plant.
We would like to go deeper into the issue and
share with you the 4+1 key factors we think
should be taken into account when choosing or
designing a heat tracing solution.
Energy Efficiency
This is particularly relevant since the less energy the plant self-consumes, the
more energy it has to sell, in other words: Managing energy efficiency
improves plant´s productivity.
Connectivity: Control and Monitoring
To be able to detect a problem in a timely manner gives the plant´s staff the
opportunity to react and fix any malfunction in the shortest period of time. On
the other hand, it is nice to know that everything is working fine, have
periodical reports to confirm it, and use this information to make further
improvements.
Usability
The staff should be properly trained and the software intuitive enough to
provide a fast response whenever a crisis arises, as well as to manage the day to
day tasks without a glitch.
Safety and Reliability
Yes, the tracing system is no more than 0,5% of the total investment of any
plant, but if it does not work properly the loss of productivity, and of money,
can be substantial. A safe and reliable solution makes everybody involved in the
plant sleep better at night.
An optional one: Flexibility
This one is up to you, it depends more of your business model. In AKO we
believe that the success of our AKOTRACE® solution relies, in addition to the
above mentioned, on its flexibility to adapt to any project, and to any plant.
Whether it uses parabolic cylinder technology or concentrating solar tower,
AKOTRACE® is designed to be flexible enough to suit every client´s needs. The
projects may be different, but the outcome is always satisfactory.
8

The structure of an optimal heat tracing
solution (I)
After considering all factors involved in the decision making process when
choosing an electrical heat tracing solution, it is time to describe how the
system works. In our case, we want to share with you the structure of our DCS
AKOTRACE® solution, a framework that holds three levels of performance
areas designed to fulfill the needs of any CSP plant.
Field and installation
From the base up, Level 3 is made up of all the heat cables and heaters, probes,
accessories, lagging, and, in general, of any element necessary for the installlation
of the tracing system.
Control and Power
Level 2 distributes the necessary power to the tracing system, regulating and
controlling its delivery according to the information received (thermal probes
and electrical supply; safety indicators, etc)
Supervision and Connectivity
Finally, Level 1 monitors and supervises the tracing system connecting it to both
the plant´s DCS system and to possible telemanagement points.
All three levels of our AKOTRACE® structure are supported by a layer of services
that include maintenance (reactive, proactive and preventive), engineering,
project management, installation and implementation.
In our next post we´ll do a more detailed analysis of the role each one of the
levels play in the structure of our AKOTRACE® electrical heat tracing system.
9

The structure of an optimal heat tracing
solution (II)
The goal of any electrical heat tracing system is to maintain the temperature,
avoiding the freezing of either water or heat transfer fluids.
How AKO does it? Let us explain in detail the three-level structure of our
AKOTRACE® electrical heat tracing system.
Field and Installation (level 3)
It´s made up of all the elements in the
system´s control and is where the electrical
heat tracing circuit is placed. It
includes all the necessary field components,
and depending on the process
needs each control can have:
� Either standardized or custom made heating elements, depending on the
tracing needs, including MI Cable, Self Regulating Cable, heaters and all
accessories required for a full installation
� Up until 4 thermal probes with different redundancy options, this guarantees
data reliability.
� Current probes that constantly monitor the system´s control energy selfconsumption,
warning of any drop below certain values, allowing us to
identify possible failures in those cases when several tracing sections are
integrated into the same system´s control
Control and Power (level 2)
In this level our PROTrace® cabinets
are in charge of monitoring
and distributing the power from
the connection point to system´s
control. They can have different
mechanism of redundancy to avoid
malfunction in case of failure or
during maintenance. They are fully
adaptable. Based on the application,
our PROTrace® cabinets can
be concentrated in different locations or distributed throughout the field. Their
final placement depends on the technical and economical needs of the project.
10

Our system´s control is based on our DUOControl Trace, founded on a PLC
Platform, and integrated into PROTrace® cabinets. It receives data from the
thermal probes and power supply, protection conditions, configuration
variables, etc, and it acts accordingly, regulating the output power to reach and
maintain the desirable temperature, thanks to our advanced control algorithms.
Inside our PROTrace® cabinets there is the possibility to include the kind of
control, via contactor or SSR; the air conditioning or distribution elements and
the automatic transfer switch.
It also accommodates safety and protection elements such as magneto-thermal
circuit breaker, differential circuit breakers protection and a contactor´s security
system in each control, adding an extra safety component in case of switcher´s
failure.
Supervision and Connectivity (level 1)
Our ProTrace® cabinets are stick to
each other with optical fiber connectors.
Their ring configuration allows
for non-stop communication in case
of malfunction in one of the links.
In this ring configuration we have
our DUOWarm Trace, supervising
key variables such as power distribution
and the environment conditions in the cabinet. It also functions as a gateway
with the plant´s DCS system and with the firewall that allows the internet
connection to manage the installation remotely. It has a redundancy system to
avoid communication breakdowns and to facilitate maintenance work.
The local operator panel, made up of a PC Panel with our control software
AKONet Trace, only needs an Ethernet link to the network control DUOControl
Trace, allowing for the total control and supervision of the tracing installation.
We have just share with you the electrical heat tracing system that makes us
worldwide leaders in the sector. We have installed this architecture solution in
more than 25 plants, but we are constantly looking to innovate and find new
ways to optimize our system and at the same time, the productivity of any CSP
plant.
11

Optimal installation of the Electrical
Heat Tracing System (I)
We start a series of posts talking about
the electrical heat tracing elements
installed in the field since the way the
tracing system is installed in any given
surface affects the uniformity of the
reached temperature.
AKO´s experience in this matter, installing
our AKOTRACE® solution, the
most trusted and used electrical heat
tracing system worldwide, gives us a unique vision on how to handle this
critical element in any CSP plant. First of all, before starting any installation it is
important to double check all materials and plan in advance their distribution
following design requirements.
Heating cable
The kind of heating cable to be installed should, besides bringing in the
necessary power to compensate thermal loss, endure the maximum process
temperature of the plant.
It has to be distributed uniformly, reinforcing its presence in areas with higher
probabilities of thermal loss.
If the cable applies more power than it should, the temperature readings will be
higher, on the other hand, if it applies less power it can create cold spots,
causing problems to the plant´s overall.
Special care should be taken when installing the heating cable in critical points
like pipe junctions, to avoid circuit interference operation.
There are some specific criteria to be taken into account when installing
redundant heaters, like the distance between themselves or between the cables
and the probes, but in any case, both should behave the same way.
The heating cables with mineral insulation should be handled with extra caution
due to its stiffness, making its handling more difficult.
Another important characteristic of the heating cable is that changes
temperatures, expanding and contracting constantly, thus obliging the
installation of an anchoring system capable of enduring such fluctuations.
Finally, the tracing system should not represent an obstacle when replacing,
when necessary, elements like valves, probes, etc.
12

Temperature probes
The heating elements and the thermal bridges influence the temperature
readings measured by the probes.
A probe that is too close to the heating element causes a lower temperature
reading. On the other hand, if the probe is installed close to a thermal bridge,
the temperature reading will be above the required one.
If the installation requires probe redundancy, they should be installed depending
on the configuration defined by control.
In following posts we´ll talk about wiring junction boxes, brackets and how to
audit the installation to ensure optimum plant´s performance.
13

Optimal installation of the Electrical
Heat Tracing System (II)
We continue with the series of post we
started a few days ago about the electrical
heat tracing elements installed in the field.
This time we are going to focus on wiring
junction boxes, brackets and how to audit
the installation to ensure optimum plant´s
performance.
Junction boxes and brackets
The junction boxes, used to connect the heating cables or the temperature
probes, must be installed in a way that facilitates its access, but, at the same
time, they should be protected from rain and must avoid excessive mechanical
exposure. Extra protection should be added when the boxes are installed in an
area classified as explosive atmosphere.
About the brackets used for the boxes set up, (and installed over the surface
where it is necessary to control the temperature) we should take into account
that they could cause additional thermal loss, meaning that this point could get
cooler. Depending on the situation it would be convenient the use of an
additional heating cable extension to compensate for possible thermal losses.
Compliance checks and installation logs
Installation inspection is carried out in two phases: The first one takes place
after the installation of the heat tracing system and before lagging.
At this time we have to make sure that all the materials used are undamaged
and that the installation complies with the established requirements.
We should take into consideration that any intervention in the electrical heat
tracing system after lagging requires its removal, that´s why all the necessary
checks have to be made before. This is a critical reminder since any mistake
detected can be easily corrected at this point, but after lagging, the costs of any
repair just skyrockets.
Among the most important checks we should pay special attention to the
installation of the heater and its probes, making sure that all elements are fixed
correctly, properly labeled, and, most especially, they should comply with the
project requirements.
That´s what AKO has learnt over years of research and multiple installations,
the kind of experience that have made our AKOTRACE® solution the most
trusted and used electrical heat tracing system worldwide.
14

AKOTRACE ® Solution for HTF areas
We continue in this post dissecting our AKOTRACE® Electrical Heat Tracing
system, focusing now in our solution for HTF areas.
First of all, let´s establish three critical issues that our solution takes care of:
� Maintenance of temperature between 50 and 60 ºC
� Focus on temperature maintenance, no heating
� Reduction of heat loss
Since in the HTF area we just have to
maintain the temperature, between 50-60
ºC, we only need so much power (compared
to the Molten Salts area) meaning
that the tracing system´s energy consumption
is also low. This reduces thermal loss
in areas with higher levels of exposure,
that´s the case of valve bonnets, that doesn´t need any extra tracing.
Oscillation levels of temperature in these zones make the ON/OFF regulation
the most suitable solution, with a lower number of commutations (start/stop)
from the system, allowing the use of contactors to control it, hence reducing
unnecessary costs in components. This kind of regulation is available in our
DUOControl Trace.
Occasionally, it may be necessary to integrate several sections of trace
connected to the same system control. In these cases the use of current probes
along with our AKONet Trace system allows us to identify breaks in any of the
legs by detecting a decline in energy consumption.
Taking the above mentioned into account, and thanks to the flexibility of our
AKOTRACE® solution, we can reduce costs without losing efficiency, always
prioritizing the safety and security of the plant´s process.
In our next post we´ll specify how our AKOTRACE® Electrical Heat Tracing
solution works in Molten Salt areas.
15

AKOTRACE ® Solution for Molten Salt
areas
As we promised, this post will now talk
about our AKOTRACE® Electrical Heat Tracing
system, for molten salt areas. First we
are going to highlight four critical issues that
our solution takes into consideration:
� Temperature should be maintained at
265 ºC
� There are two kind of tracing circuits:
for temperature maintenance and for heating.
� Higher levels of thermal loss due to higher temperature readings
� Tracing is especially critical in this area and requires a higher level of
readiness.
Thermal loss is higher in molten salt areas due to the higher levels of temperature
readings that should be maintained. Precision is key when regulating the
temperature in this area to be energy efficient and avoid unnecessary
overheating.
The proper regulation algorithm for this application is the Proportional-
Integrated (PI), available in our DUOControl Trace, because it allows each
circuit to be more specific regarding the response speed, and at the same time it
achieves a very precise and reliable regulation, which translates into
temperature fluctuations, with regards to the SP, under a 1 ºC. Since the PI
regulation means variable connection/disconnection cycles, the commutation
element more suitable is the solid state switch-off relay that allows for an
unlimited number of commutations.
There are some circuits that require extra power to guarantee two kind of
working modes: temperature maintenance and heating. Furthermore, this
heating should be done in a limited period of time and making sure not to
surpass the materials design temperature. Our DUOControl Trace application
has some functionalities to control the heating process during both the ramp-up
and the steady state periods.
Due to the extra power, the malfunction of any of the control elements could
cause an excessive temperature increase. To correct this problem, our
AKOTRACE® Electrical Heat Tracing solution offers the option to get a safety
contactor that disconnects temporarily that particular tracing section in case it
reaches the “Safety Temperature Reading”, generating an alarm in both the
operator´s local panel and in the DCS.
There are some critical points that should be treated in a special manner. For
these points AKO has specific solutions that have already been used successfully
in various plants. AKO´s vision allows for a more adaptable installation, specially
designed to cover any plant´s needs, providing each area the necessary
resources according to its importance or criticality in the production process.
16

PROTrace ® : Control and power cabinets
for electrical trace circuits (I)
A very important component in any trace installation is the power and control
cabinet. Its main function consists on monitoring and managing power from the
power supply to the trace circuits, although it can also incorporate subsystems
depending on the installation needs.
AKO has a wide range of cabinets with multiple configurations adaptable to any
installation needs. According to its structure they can be categorized by:
� PROTrace®: They adapt to each plant´s requirements (tower o parabolic through
concentrator) and to the application (molten salts or HTF). They provide a high
safety standard because they allow, among other things, power supply
redundancy in power connections, power sources and probes, as well as
monitoring of the cabinet´s performance.
� ProTrace Distributed: Designed for projects where there is a large distance
between the trace circuits in the electrical rooms (we´ll talk about these ones in
following posts)
PROTrace® cabinets
A standard configuration of the cabinets for solar plants (with molten salts
storage) contains the following components:
Connection and supply
Include all the generic services: Generic
protection, transformers, power supply
for system´s control and supply network
analyzers. The power supplies and connections
can be redundant (we recommend
it in critical processes). In these
cases it monitors the quality of the network
to switch from one connection to
another when needed.
Trace control
Gets the information from different elements of the installation (temperature
probes and electric current, protections status, framework variables, etc) and
acts consequently, modulating the start power in each trace circuit.
Switching
The circuits get connect or disconnected depending on the information gotten
from trace control. Depending on the projected switching frequency, that is the
preset regulation algorithm, they can be contractors or SSR (switch-off relays).
In our next post we´ll continue outlining more components of our PROTrace®
cabinets, including our AKODUO safety system.
17

PROTrace ® : Control and power cabinets
for electrical trace circuits (II)
We continue where we left it in our last post, talking about AKO´s PROTrace®
cabinets. As we have already stated a standard configuration of the cabinets for
solar plants (with molten salts storage) contains the components already
mentioned in our last post plus the following:
AKODUO Safety
In case of reaching safety temperature readings, the system disconnects the
power supply in the damaged circuit using a second safety contactor. This
functionality protects both the heating element and where it is installed in case
of malfunction in the switching elements.
Protection
The cabinets have magneto thermal protection and differentials for both the
fuse boxes and the trace circuits.
Operator panel
They also have an operator panel to monitor and set up the installation
system´s control. Its local installation simplifies any maintenance job both in the
fuse boxes and the field.
Fuse boxes monitoring
To ensure the proper functioning of the cabinet, some points are monitored
(detection of stress, generic protection status, internal temperature, etc.)
generating alarms both in the DCS and in the operator panel. This allows us to
do preventive maintenance, avoiding major problems in the fuse boxes and the
trace installation.
Communications
The cabinets include the communication
network switchers from all the elements of
the system´s control: PLC´s, monitoring,
operator panel, getaway link with plant´s
DCS, and firewall remote management
(when applicable). Communications redundancy
is available to avoid possible link
breakages.
Cooling and Welding
They maintain the temperature inside the cabinet within the established ranges
in the design phase. It is very common to install the power and control cabinets
unsheltered, making the cooling and welding functions very important to ensure
the right functioning of all its elements. We still have more to say about AKO´s
cabinets. In some other post we´ll describe our PROTrace® Distributed, part of
our wide range of cabinets with multiple configurations, adaptable to any
installation.
18

PROTrace ® : Control and power cabinets
for electrical trace circuits (III)
We´ve already mentioned that AKO has a
wide range of cabinets with multiple
configurations adaptable to any installation
needs. Now we are going to describe
our PROTrace® Distributed, a cabinet
designed for projects where there is
a large distance between the trace circuits
in the electrical rooms.
These cabinets differentiate themselves
from the rest because they distribute
power and control throughout the entire
installation by means of three different kinds of cabinets:
� Main Cabinet: Distributes power to secondary cabinets and it acts as a
liaison between the plant´s DCS and the tracing system. It includes a local
panel control
� Secondary Cabinet: Distributes power and communications generated from
the main cabinet to the PROTrace D3 and/or D6 cabinets.
� PROTrace D3 and D6 cabinets: They receive power generated from the
secondary cabinets and then they apply this power to the tracing system,
regulating it according to its configuration and each circuits probe readings
This structure aims to shorten the distances between the control elements and
the tracing circuits, thus dramatically reducing tracing and installation costs.
They are designed for CSP plants with HTF or BOP systems. They are not
suitable in sales or in the process industry.
Any change in the main cabinet´s configuration (where we found the panel
control) or in the plant´s DCS, will be sent to the PROTrace D3 and D6 cabinets
throughout a communications network, but, nevertheless, each cabinet is
autonomous, meaning that they will be working fine even if the network fails.
In our next post we´ll give you more details about our PROTrace D3 and D6
cabinets.
19

PROTrace ® : Control and power cabinets
for electrical trace circuits (IV)
As we promised in our previous post, we are going now to give you more details
about how our PROTrace D3 and D6 cabinets work.
They are available with 3 or 6 control outlets (D3: up to 3 circuits and D6: up to
6 circuits). Each cabinet has two protection elements, independent from each
other, one aimed to control and a second one to power. It includes a contactor
per circuit to regulate outlet power, a CPU, our DUOControl Trace (based in an
industrial PLC, with high levels of availability and reliability) a remote input
module Pt100 and a resistance welding with thermostat.
Their main functions are:
� Circuit alarm management
� Start timer circuit to avoid consumption
peaks
� Temperature supervision per circuit
� Independent set point per circuit
� 2 kinds of control per circuit: ON/OFF
and CETA
� Independent input per circuit
� 3 alarm temperature thresholds: minimum,
maximum and critical (it stops
regulation)
� Output power set per circuit in case of
probe malfunction
20

DUOControl Trace: The brain inside
AKO´s ProTrace ® cabinets (I)
When talking about the structure of an
optimal heat tracing solution we have already
highlighted in previous posts the
importance of what we call level 2 of the
installation, referring to control and power
and where our ProTrace® cabinets are
placed. Within these cabinets is where
you´ll find its “brain”: Our DUOControl
Trace, a device in charge of integrating the
logic of the electrical tracing control, monitoring
the input signals (valves, protection status, alarms) and acting accordingly
on the heating elements.
The DUOControl Trace devices have been specifically designed to facilitate the
configuration and monitoring of the electrical tracing installation. They use PLC
technology, like control hardware, and they provide a high level of reliability to
our DCS-AKOTRACE® system.
Among other functionalities they include the following:
� 4 temperature probes per tracing control, with several redundancy options
� Temporary synchronized disconnection for shedding maneuvers
� Sequential control connection to avoid consumption peaks
� Up to 10 alarm outputs (depending on the configuration)
� 24 process alarms per tracing control
� Independent protection outputs that will disconnect the main output in case of
overheating
� Theoretical totalizing of consumed energy
� Transistor output (TRT) that allows for an unlimited number of maneuvers
� It has 1 or 2 current probes per tracing control, allowing for the supervision of
consumption in single or three phase circuits.
� SD card slot, which allows to upload or to save the controller configuration to
simplify start off and substitution operations
Its modular construction makes it adaptable to any installation. It can
communicate to the DCS plant by means of several protocols: MODBUST/TCP,
Profibus, Devicenet, etc.
Each controller can manage up to 32 tracing controls, performing activation
work in the heating cables, as well as supervising the protection state and status
variables in addition to managing the alarm system.
In our following post we´ll talk about the 3 regulation algorithms (PI, ON/OFF
and CETA) included in our DUOControl Trace devices.
21

DUOControl Trace: The brain inside
ProTrace ® cabinets (II)
We continue talking about the structure of an optimal heat tracing solution, but
this time focusing on our DUOControl Trace device, the brain inside our
ProTrace® cabinets.
We have already stated that depending on the needs of each circuit it has 3
regulation algorithms (PI, ON/OFF and CETA)
PI Control
It is the most appropriate control
for areas that require less temperature
variation maintenance from Set
Point.
The controller is constantly calculating, according to several variables, the
necessary power to reach and maintain the Set Point temperature, and it also
modulates the output with short term connection/disconnection cycles.
In addition to that, it checks the velocity in which the material gets heated,
making sure that it does not exceed its limits.
Each DUOControl Trace has 4 customized PI parameter sets that permit to
adjust the speed response independently in each control.
ON/OFF Control
Fit for areas allowing for greater temperature variations from Set Point.
The output remains active until reaching Set Point temperature plus the
differential programmed, once it has reached this point, it remains disconnected
until reaching Set Point temperature.
CETA Control
This kind of control is suited to compensate thermal losses based on room
temperature, avoiding the cooling of fluids inside the pipes.
The controller estimates the necessary power to reach and maintain Set Point
temperature depending on room temperature and modulates the output with
long-term connection/disconnection cycles.
22

AKONet Trace, AKO´s control software
for EHT systems
We have previously stated in several posts that our AKOTRACE® Electrical Heat
Tracing system is designed in a three-level structure.
� Level 3- Field and Installation
� Level 2- Control and Power
� Level 1- Supervision and Connectivity
It is in the last level, Supervision and Connectivity, where we find AKO´s
newest software to monitor, supervise and control electrical heat tracing
systems.
AKONet Trace it´s been designed to be accessible and easy to use, with great
efficiency and enough versatility for optimal performance even in the most
ambitious projects.
It´s a web application accessible from a PC and remotely from any navigator
connected to the net, even from your phone. One of its setting options includes
the possibility to receive alerts via e-mail and/or SMS.
But there is nothing like a live demo on how the application works to give you a
better sense of its functionality and advantages in any CSP plant´s EHT
installation.
Watch it on YouTube!
http://www.youtube.com/watch?feature=player_embedded&v=9CDepX5HcBU
23

DUOVision Touch Trace: Designed for
small EHT systems
We had previously talked about our DUOControl
Trace, which we consider to be the brain inside
our ProTrace® cabinets. Now we are going to
describe you one device that works along with it:
DUOVision Touch Trace.
DUOVision Touch Trace is a 7” high contrast
touch screen that together with DUOControl
Trace controllers allows to framework and
monitor small electrical heat tracing installations
with up to 128 tracing controls, or, in other words, each screen can manage up
to 4 DUOControl Trace with 32 tracing controls each one.
Each tracing control regulates the tracing element´s temperature activating and
deactivating the heating cables, supervising its protections, as well as the
different status variables and the alarm management.
The screen carries out monitoring and frameworking functions, leaving the
tracing management to DUOControl Trace, allowing for the installation to keep
on working even when there is a malfunction. Its main responsibilities are:
� Creation of tracing control groups when needed: Allows for the organization of
different tracing sections in groups, to facilitate its identification during
monitoring or frameworking.
� Up to 3 user levels, according to its permissions: Visualization, operation and
maintenance, which ensures that only qualified people would be able to access
and modify tracing installation frameworks.
� Easy to use frameworking: Allows to change any installation framework even if
you are not familiar with programming.
� Graphical identification of control status. Just with a quick look to the screen
you can see the installation´s tracing status. When an incident arises (disabled
controls, alarms, etc.) the screen will display alarm icons or it will change the
regular colors of the control or control group affected by the problem.
� SD card slot: Which allows for making system´s configuration backups and
restore them when needed, facilitating maintenance work.
� Protection level IP 65: Allows for its installation in industrial environments
� Easy to connect: It only requires power feed and to be connected to the
DUOControl Trace network (Ethernet with RJ45)
� Theoretical totalizing of consumed energy: It allows to know the theoretical
value of the consumed power.
To recap, the DUOVision touch Trace is the ideal alternative to AKOnet Trace,
when working in small EHT installations.
24

AKO´s MI heating cable
One of the key elements in any electrical heat tracing installation is the use of
the right heating cable. In this post we are going to share with you the
specifications of AKO´s Mineral Insulated (MI) heating cable.
In any EHT installation, the maintenance
temperature and the process temperature
determine the kind of heating cable more
suitable to use.
The maintenance temperature is usually
lower than the process temperature, this
fact is determinant to decide the maximum
power that the heating cable can endure
when connected, while the process temperature
is needed to avoid the damage of the
insulated cable when it is disconnected.
In instances when process temperature reaches 450 ºF readings, or when the
maintenance temperature is around 350 ºF, which requires high power from the
heating cable, it gets really difficult to pick the right heating cable.
But AKO´s heating cable with mineral insulation can be used in process temperature
readings of up to 1100 ºF and in maintenance temperature around 900 ºF.
Some other specifications of this cable, besides the power and temperature
requirements, are, among others:
� Corrosion resistance
� Mechanical resistance
� Usable in explosive atmospheres
� Easy to use
When the corrosion is high, the cable is made with a cover with a high nickel
content (Alloy 825). AKO´s MI cable also has a high mechanical resistance, and
at the same time, it is adaptable to the surface in which it has to be applied.
The heating element varies regarding the material or diameter depending on
the lineal resistance we want to achieve. The material used is a mixture of nickel
with other metals.
The heating cable has a heating zone and one or two cold ends to be connected
to the power supply. When the cable is 1 core, it has two cold ends for power
supply, while the 2 cores cable just has one cold end. When assembled in the
power supply, each cable´s cold end includes a cable gland.
The insulation between the cable´s active part and its cover is made out of
Magnesium Oxide (MgO).
AKO´s heating cables with mineral insulation are certified to be used in
explosive atmospheres classified as Class 1 Division 2, Groups A, B, C & D.
25

Temperature Sensors I
In this post we will now talk about the different kind of probes used in tracing
installations and which one works better depending on the circumstances.
Which probe to use and when
In order to install an electrical tracing
to maintain a given temperature,
it is required the installation of a
control loop with a signal provided
by a temperature sensor.
When selecting the temperature sensors we have to take into account the temperature
ranges they will have to endure since the process temperature tends
to be higher to the temperature to be maintained by the electrical tracing.
When the temperature ranges are about -60 ºF and 1100 ºF, the temperature
sensor more suitable is a Pt100 probe. For readings higher or closer to the
provided temperature, such is the case of solar thermal power tower plants, it´s
better to use a type K thermocouple sensor.
The placement of the sensors on the field close to the traced surfaces entails
that they have to be extended to the installation´s electrical cabinets. When
using Pt100 probes we recommend a converter to 4-20mA, making it even
more necessary when installing type K thermocouples. The 4-20 mA signal
avoids temperature measurement mistakes caused by possible electromagnetic
interferences, which makes its application very common in industrial
environments.
AKO has convertors for both Pt100 probes and type K thermocouples to
4-20 mA placed in connection boxes to facilitate its installation.
In our next post we´ll talk about redundancy and the required temperature in
different points.
26

Temperature Sensors II
We continue analyzing the kind of probes used in tracing installations and which
ones are more suitable depending on the circumstances.
Where to install a temperature sensor
Now we are going to focus in temperature measurement in different points of
the tracing system and its redundancy. Usually there is a temperature sensor in
each control area of an electrical tracing installation. But, depending on the
criticality of the set up it could be necessary the installation of several sensors in
the same area. The distribution of these sensors is made in three different ways
depending of the installation´s design requirements:
� In a redundancy point
� In several points without redundancy
� In several points with redundancy
Our controller DUOControl Trace allows for the configuration of the mentioned
sensors, and it controls the system based in its temperature readings. Any
temperature deviation above a determined value or the damage of a sensor will
trigger distinct alarms allowing for a faster and more precise identification of
the problem.
In our next post we will talk about AKONet Trace, our software that monitors,
supervises and controls electrical heat tracing systems. We will explain in detail
how the alarm system works and we will highlight its mobility.
27

AKONet Trace: Alarm Management (I)
We have already described some of
the advantages of our AKONet Trace,
the software that allows for the
configuration and monitoring of
AKO´s electrical tracing installations.
In this case we will focus in the
alarm management´s functionality.
In any electrical tracing installation
the prompt detection of any system´s
anomaly is vital, to both
ensure a proper plant´s performance and to avoid future greater and costlier
breakdowns. For that reason AKO has been working relentlessly to provide
AKONet Trace software with the right tools to manage this kind of incidents in a
rapid and efficient manner.
In case of detecting any anomaly (such as higher or lower temperature readings,
mistakes in probes readings, communications breakdowns, etc.), the system
activates an alarm that gets displayed on the screen in different ways:
� Alarm notification bar: Located in the upper side of the screen, it shows
the active alarms in sequence. Pressing over any of the alarms it is possible
to gain direct access to the alarm´s listing screen that provides detailed
information about the active alarms, offering the possibility to confirm it
or get access to the strained control.
� Alarm´s listing: It shows the entire installation´s alarm listing, being even
able to filter the results throughout different parameters (by dates, by
active alarms, by pending confirmation, etc.) The results can be exported
to PDF or Excel, facilitating its analysis in operating reports.
In our next post we will continue describing more functionalities of the software
including how it works with the system´s control and the categorization of the
alarms depending on its source.
28

AKONet Trace: Alarm Management (II)
We continue with the analysis of our
AKONet Trace, the software that allows
for the configuration and monitoring of
AKO´s electrical tracing installations.
We had previously described two different
ways the software has to display
the alarms on the screen: by means of
an alarm notification bar and with an
alarm´s listing.
Now let´s see how the software works with the system´s control, plus we will
show you how it categorizes the alarms depending on its source.
� Control´s active alarms: When reviewing the details of any system´s control,
you can detect all the active alarms and even confirm them in case it is
necessary.
� Alarm´s icons: There are 3 alarm´s icons depending on where they were
originated:
� I/O Service: Alarms that detect malfunctions in the elements inside the
electrical cabinet: internal temperature and electrical protection status of
the different electrical elements.
� Generics: This kind of alarm gets activated by a cluster, meaning that it can
affect all the tracing circuits controlled by the cluster.
� Control: An alarm generated by any of the installation´s tracing controls. It
also displays an alarm icon in the strained control. When monitoring
groups or cabinets, this same icon gets displayed in the strained group or
cabinets.
In addition to the above mentioned, to facilitate the problem´s resolution,
besides indicating the cause of the alarm, the software also displays the name
of the PLC affected, the name of the control and to which group it belongs, plus
the time and date it was generated. These data allows the maintenance
personnel to locate and repair the breakdown in a very short period of time.
What´s more, apart from being able to view the alarms in the PC panel where
AKONet is executed, all the alarms are communicated to the Distributed
Control System (DCS), in exceptional cases when the client demands having the
tracing system´s control connected to the DCS.
29

AKO ENGINEERING INC.
1490 South Price Road | Chandler | AZ 85286 Suite 311 | USA
Tel. (1) 480 428 5083| e-mail: akoengineering@ako.com|www.akotrace.com
We reserve the right to supply materials that might vary slightly to those described in our Technical Sheets.
Updated information is available on our website: www.ako.com.