Controls, Start-Up, Operation, Service and ... - Climayoreo

If all of the above conditions are met, the following logic is
used:
If OAT IQ.L.O and OAT OCSP and economizer is
available then purge will be enabled and the economizer will
be commanded to 100%.
Else, if OAT < IQ.L.O then the economizer will be positioned
to the IAQ Purge LO Temp Min Pos (Configuration
IAQIAQ.PIQ.P.L)
If neither of the above are true then the dampers will be
positioned to the IAQ Purge HI Temp Min Pos (Configuration
IAQIAQ.PIQ.P.H)
If this mode is enabled the indoor fan and heat interlock
relay (VAV) will be energized.
IAQ Purge (ConfigurationIAQIAQ.PIQ.PG) — This
is used to enable IAQ pre-occupancy purge.
IAQ Purge Duration (ConfigurationIAQIAQ.P
IQ.P.T) — This is the maximum amount of time that a purge
can occur.
IAQ Purge Lo Temp Min Pos (ConfigurationIAQ
IAQ.PIQ.P.L) — This is used to configure a low limit for
damper position to be used during the purge mode.
IAQ Purge Hi Temp Min Pos (ConfigurationIAQ
IAQ.PIQ.P.H) — This is used to configure a maximum position
for the dampers to be used during the purge cycle.
IAQ Purge OAT Lockout Temp (ConfigurationIAQ
IAQ.PIQ.L.O) — Nighttime lockout temperature below
which the purge cycle will be disabled.
OPTIONAL AIRFLOW STATION — The ComfortLink
controls are capable of working with a factory-installed optional
airflow station that measures the amount of outdoor air entering
the economizer. This flow station is intended to measure
ventilation airflows and has a limitation as to the maximum
flow rate it can measure. The limits are 18,000 cfm for sizes
030-050 and 31,000 cfm for sizes 055-100.
All configurations for the outdoor airflow station can be
found in the ConfigurationECONCFM.C, sub-menu.
For this algorithm to function, the Outdoor Air Cfm Sensor
Configuration (OCF.S.) must be enabled.
There are three set point configurations:
O.C.MN — Econ OACFM DCV Min Flow
O.C.MX — Econ OACFM DCV Max Flow
O.C.DB — Econ OACFM MinPos Deadbd
When the outdoor air cfm sensor is enabled, the Economizer
Min.Position (ConfigurationIAQDCV.CEC.MN) and
the IAQ Demand Vent Min.Pos (ConfigurationIAQ
DCV.CIAQ.M) will no longer be used. During vent periods,
the control will modulate the damper to maintain the outdoor
air intake quantity between O.C.MX and O.C.MN. The indoor
air quality algorithm will vary the cfm between these two
values depending on ConfigurationIAQAQ.SPDAQ.L
and the ConfigurationIAQAQ.SPDAQ.H set points
and upon the relationship between the IAQ and the outdoor air
quality (OAQ).
The economizer’s OA CFM Minimum Position Deadband
(O.C.DB) is the deadband range around the outdoor cfm
control point at where the damper control will stop, indicating
the control point has been reached. See the Economizer section
for more information.
Humidification — The P Series ComfortLink controls
can control a field-supplied and installed humidifier device.
The ComfortLink controls provide two types of humidification
control: A discrete stage control (via a relay contact) and a proportional
control type (communicating to a LEN actuator). The
78
discrete stage control is used to control a single-stage humidifier,
(typically a spray pump). The proportional control type is
typically used to control a proportional steam valve serving a
steam grid humidifier.
The ComfortLink controls must be equipped with a controls
expansion module and an accessory space or return air relative
humidity sensor.
If a humidifier using a proportional steam valve is selected,
the Carrier actuator (Carrier Part No. HF23BJ050) must be
adapted to the humidifier manufacturer’s steam valve. Contact
Belimo Aircontrols for information on actuator linkage adapter
packages required to mount the actuator on the specific brand
and type of steam valve mounted by the humidifier
manufacturer.
The actuator address must be programmed into the ComfortLink
unit’s humidifier actuator serial number variables.
SETTING UP THE SYSTEM — These humidity configuration
are located in the local displays under Configuration
HUMD. See Table 58. Related points are shown in Table 59.
Humidifier Control Configuration (HM.CF) — The humidifier
control can be set to the following configurations:
• HM.CF = 0 — No humidity control.
• HM.CF = 1 — Discrete control based on space relative
humidity.
• HM.CF = 2 — Discrete control based on return air relative
humidity.
• HM.CF = 3 — Analog control based on space relative
humidity.
• HM.CF = 4 — Analog control based on return air relative
humidity.
Humidity Control Set Point (HM.SP) — The humidity control
set point has a range of 0 to 100%.
Humidifier PID Run Rate (HM.TM) — This is the PID run
time rate.
Humidifier Proportional Gain (HM.P) — This configuration
is the PID Proportional Gain.
Humidifier Integral Gain (HM.I) — This configuration is the
PID Integral Gain.
Humidifier Derivative Gain (HM.D) — This configuration is
the PID Derivative Gain.
OPERATION — For operation, PID control will be utilized.
The process will run at the rate defined by the Configuration
HUMDH.PIDHM.TM. The first part of humidity
control tests the humidity control configuration and will turn
on corresponding configurations to read space or return air relative
humidity. If the supply fan has been ON for 30 seconds
and the space is occupied, then the humidification is started.
Actuator Control — Control is performed with a generic PID
loop where:
Error = HM.SP – humidity sensor value (SP.RH or RA.RH,
depending on configuration).
The PID terms are calculated as follows:
P = K * HM.P * error
I = K * HM.I * error + “I” last time through
D = K * HM.D * (error – error last time through)
Where K = HM.TM/60 to normalize the effect of changing the
run time rate
Relay Output Control — If the humidity sensor reading is
greater than the humidity set point then the humidity relay
(OutputsGEN.OHUM.R) is closed. The relay will open
when the humidity is 2% less than the humidity set point.