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

Table 53 — Dirty Filter Switch Points
ITEM EXPANSION RANGE
CCN
POINT
ConfigurationUNIT
SENSFLT.S
Filter
Stat.Sw.Enabled ? Enable/
Disable
FLTS_ENA
InputsGEN.I
FLT.S
Filter Status Input DRTY/CLN FLTS
Monitoring of the filter status switch is disabled in the
Service Test mode and when the supply fan is not commanded
on. If the fan is on and the unit is not in a test mode and the
filter status switch reads “dirty” for 2 continuous minutes, an
alert is generated. Recovery from this alert is done through a
clearing of all alarms or after cleaning the filter and the switch
reads “clean” for 30 seconds.
NOTE: The filter switch should be adjusted to allow for the
operating cfm and the type of filter. Refer to the accessory
installation instructions for information on adjusting the switch.
Economizer — The economizer control is used to manage
the outside and return air dampers of the unit to provide ventilation
air as well as free cooling based on several configuration
options. This section contains a description of the economizer
and its ability to provide free cooling. See the section on indoor
air quality for more information on setting up and using the
economizer to perform demand controlled ventilation (DCV).
See the Third Party Control section for a description on how to
take over the operation of the economizer through external
control.
The economizer system also permits this unit to perform
smoke control functions based on external control switch
inputs. Refer to the Smoke Control Modes section for detailed
discussions.
Economizer control can be based on automatic control
algorithms using unit-based set points and sensor inputs. This
economizer control system can also be managed through external
logic systems.
The economizer system is a factory-installed option. This
option includes a factory-installed enthalpy control device to
determine the changeover condition that permits free cooling
operation. This unit can also have the following devices
installed to enhance economizer control:
• Outside air humidity sensor
• Return air humidity sensor
• Outside airflow control
NOTE: All these options require the controls expansion module
(CEM).
The P Series economizer damper is managed by a communicating
actuator motor(s). This provides the ability of the control
system to monitor, diagnose and report the health and operation
of the actuator and damper system to the local display and
CCN network, thus providing extensive diagnostic tools to
servicers.
SETTING UP THE SYSTEM — The economizer configuration
options are under the Local Display Mode Configuration
ECON. See Table 54.
Economizer Installed? (EC.EN) — If an economizer is not
installed or is to be completely disabled the configuration
option EC.EN may be set to No. Otherwise in the case of an installed
economizer, this option must be set to Yes.
Economizer Actuator 2 Installed? (EC2.E) — For 48/50P055-
100 units, a second economizer actuator is required. For sizes
055-100, set this configuration to Yes.
Economizer Minimum Position (EC.MN) — The configuration
option EC.MN is the economizer minimum position. See
the section on indoor air quality for further information on how
to reset the economizer further to gain energy savings and to
more carefully monitor IAQ problems.
67
Economizer Maximum Position (EC.MX) — The upper limit
of the economizer may be limited by setting EC.MX. It defaults
to 98% to avoid problems associated with slight changes
in the economizer damper’s end stop over time. Typically this
will not need to be adjusted.
Economizer Trim for Sum Z? (E.TRM) — Sum Z is the
adaptive cooling control algorithm used for multiple stages
of mechanical cooling capacity. The configuration option,
E.TRM is typically set to Yes, and allows the economizer to
modulate to the same control point (Sum Z) that is used to
control capacity staging. The advantage is lower compressor
cycling coupled with tighter temperature control. Setting this
option to No will cause the economizer, if it is able to provide
free cooling, to open to the Economizer Max. Position
(EC.MX) during mechanical cooling.
ECONOMIZER OPERATION — There are four potential
elements which are considered concurrently which determine
whether the economizer is able to provide free cooling:
1. Dry bulb changeover (outside-air temperature qualification)
2. Enthalpy switch (discrete control input monitoring)
3. Economizer changeover select (E.SEL economizer
changeover select configuration option)
4. Outdoor dewpoint limit check (requires an installed outdoor
relative humidity sensor installed)
Dry Bulb Changeover — Outside-air temperature may be
viewed under TemperaturesAIR.TOAT. The control
constantly compares its outside-air temperature reading against
the high temperature OAT lockout (OAT.L). If the temperature
reads above OAT.L, the economizer will not be allowed to perform
free cooling.
NOTE: If the user wishes to disable the enthalpy switch from
running concurrently, a field-supplied jumper must be installed
between TB201 terminals 3 and 4.
Enthalpy Switch — The state of the enthalpy switch can be
viewed under InputsGEN.IENTH. Enthalpy switches are
installed as standard on all P Series rooftops. When the switch
reads high, free cooling will be disallowed.
The enthalpy switch opens (reads high) when the outdoor
enthalpy is above 24 Btu/lb or dry bulb temperature is above
70 F and will close when the outdoor enthalpy is below
23 Btu/lb or the dry bulb temperature is below 69.5 F.
NOTE: The enthalpy switch has both a low and a high output.
To use this switch as designed the control must be connected to
the low output. Additionally there is a switch logic setting for
the enthalpy switch under ConfigurationSW.LGENT.L.
This setting must be configured to closed (CLSE) to work properly
when connected to the low output of the enthalpy switch.
There are two jumpers under the cover of the enthalpy
switch. One jumper determines the mode of the enthalpy
switch/receiver. The other is not used. For the enthalpy switch,
the factory setting is M1 and should not need to be changed. See
Fig. 10 for a diagram showing the settings on the enthalpy
switch.
The enthalpy switch may also be field converted to a differential
enthalpy switch by field installing an enthalpy sensor
(33CSENTSEN or HH57ZC001). The enthalpy switch/receiver
remains installed in its factory location to sense outdoor air
enthalpy. The additional enthalpy sensor (33CSENTSEN) is
mounted in the return airstream to measure return air enthalpy.
The enthalpy control jumper must be changed from M1 to M2
for differential enthalpy control. For the 2-wire return air enthalpy
sensor, connect power to the Vin input and signal to the
4 to 20 mA loop input. See Fig. 10 for diagram showing the
settings and inputs on the enthalpy switch.
There is another way to accomplish differential enthalpy
control when both an outdoor and return air relative humidity