Trane IntelliPak 2 Series, Инструкция по установке, эксплуатации и обслуживанию

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RT-SVX24Q-EN 97
Units with an Economizer
Upon entering an “occupied” mode of operation, the
RTM receives input from the remote panel to start the
supply fan. For constant volume applications, the RTM
supply fan contacts close, which energizes the supply
fan contactor. When the supply fan starts, the fan
proving switch closes, signaling the RTM that airflow
has been established. The RTM opens the economizer
dampers to the specified “minimum position”.
When a cooling request is sent to the RTM from the
zone temperature sensor, the RTM evaluates the
operating condition of the system using the supply air
temperature input and the outdoor temperature input
before sending the request to the MCM for mechanical
cooling. If the outdoor conditions are suitable for
cooling (temperature and humidity are within specified
setpoints), the RTM will attempt to maintain the zone
temperature without using any compressors. If the
zone temperature cannot be maintained within the
setpoint deadband, the RTM sends a cooling request to
the MCM. The compressor module checks the
compressor protection circuit before closing “Stage 1".
After the first functional stage has started, the
compressor module monitors the saturated refrigerant
temperature and closes the condenser fan output
contact, when the saturated refrigerant temperature
rises above the “lower limit” setpoint.
Units with Traq™ Sensor
The outside air enters the unit through the Traq™
Sensor assemblies and is measured by velocity
pressure flow rings. The velocity pressure flow rings
are connected to a pressure transducer/solenoid
assemblies. The solenoid is used for calibration
purposes to compensate for temperature swings that
could affect the transducer. The Ventilation Control
Module (VCM)Symbio™ 800 utilizes the velocity
pressure inputs, the RTM outdoor air temperature
input, and the minimum outside air CFM setpoint to
modify the volume (CFM) of outside air entering the
unit as the measured airflow deviates from setpoint.
When the optional temperature sensor is installed and
the Preheat function is enabled, the sensor will monitor
the combined (averaged) outside air and return air
temperatures. As this mixed air temperature falls
below the Preheat Actuate Temperature Setpoint, the
VCM will activate the preheat binary output used to
control a field installed heater. The output will be
deactivated when the temperature rises 5 above the
Preheat Actuate Temperature Setpoint.
When the optional CO
2
sensor is installed and DCV is
enabled, the OA damper will be modulated to control
CO
2
concentrations. If the CO
2
concentration is greater
than the Design Minimum CO
2
Setpoint the OA
damper will be opened to the Design Minimum OA
Damper Setpoint (w/o Traq™) or until the Design
Minimum OA Flow Setpoint is met (w/ Traq™).
If the CO
2
concentration is less than the DCV Minimum
CO
2
Setpoint the OA damper will be closed to the DCV
Minimum OA Damper Setpoint (w/o Traq™) or until the
DCV Minimum OA Flow Setpoint is met (w/ Traq™).
If the CO
2
concentration is between the Design
Minimum CO
2
Setpoint and the DCV Minimum CO
2
Setpoint the OA damper will be modulated
proportionally between the Design Minimum OA
Damper Setpoint and the DCV Minimum OA Damper
Setpoint (w/ Traq™) and between the Design Minimum
OA Flow Setpoint and the DCV Minimum OA Flow
Setpoint (w/o Traq™).
Low Charge Protection
For each refrigeration circuit, the entering and leaving
evaporator temperatures are used to calculate
superheat. When the calculated superheat exceeds the
Evaporator Temperature Differential Setpoint minus 5°
F but not the Evaporator Temperature Differential
Setpoint, an information only, auto-reset, High
Superheat diagnostic is initiated.
If the calculated superheat exceeds the Evaporator
Temperature Differential Setpoint, a manual reset, low
refrigerant charge diagnostic is initiated and all
compressors on the circuit are locked out.
Note that on circuits with the Variable Speed
Compressor option, the Evaporator Temperature
Differential Setpoint for that circuit will be reset based
on the active compressor capacity and the user
selected Evaporator Temperature Differential Setpoint.
Frostat™ Control
The compressor module utilizes an evaporator
temperature sensor, mounted on the suction line of
each circuit, to protect the evaporator from freezing. If
the evaporator temperature approaches the specified
setpoint, adjustable between 25°F and 35°F, the
compressor(s) will be cycled “off”. The compressors
will not be allowed to restart until the evaporator
temperature has risen 10°F above the specified cutout
temperature and the compressor(s) have been off for a
minimum of three minutes.
N No otte e:: On circuits with the Variable Speed Compressor
option, the Active Coil Frost Cutout Temperature
Setpoint for that circuit will be 5°F higher than
the user selected Coil Frost Cutout Temperature
Setpoint.
Lead/Lag Operation
When Lead/Lag is enabled, each time the system cycles
after having stages 1 and 2 “On”, “Stage 2" and the
corresponding condenser fan output will start first. The
compressor module cycles the compressors “On” and
“Off” to keep the zone temperature within the cooling
setpoint deadband. The condenser fans are cycled
“On” and “Off” to maintain the saturated refrigerant
temperature within the specified controlband.
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