Constant Volume (Cv) Units; Single Zone Variable Air Volume (Szvav); Only - Trane IntelliPak Installation, Operation And Maintenance Manual

Compressor Circuit Breakers (1CB8, 1CB9,
1CB10, 1CB11)
The Scroll Compressors are protected by circuit breakers
for 208 - 230 volt units which interrupt the power supply to
the compressors if the current exceeds the breakers "must
trip" value. For 460 -575 volt units the Scroll compressors
will be protected with Manual Motor protectors. During a
request for compressor operation, if the Compressor
Module detects a problem outside of it's normal
parameters, it turns any operating compressor(s) on that
circuit "Off" , locks out all compressor operation for that
circuit, and initiates a manual reset diagnostic.

Constant Volume (CV) Units

Zone Temperature - Cooling
Relies on input from a sensor located directly in the space,
while a system is in the occupied "Cooling" mode. It
modulates the economizer (if equipped) and/or stages the
mechanical cooling "On and Off" as required to maintain
the zone temperature to within the cooling setpoint
deadband.
Zone Temperature - Heating
Relies on input from a sensor located directly in the space,
while a system is in the occupied "Heating" mode or an
unoccupied period, to stage the heat "on and off" or to
modulate the heating valve (hydronic heat only) as
required to maintain the zone temperature to within the
heating setpoint deadband.The supply fan will be
requested to operate any time there is a requested for heat.
On gas heat units, the fan will continue to run for 60
seconds after the furnace is turned off.
Supply Air Tempering
On CV ZoneTemperature Control units, if the supply air
temperature falls 10°F below the zone temperature
setpoint up to half of the available heat capacity will be
brought on until the supply air temperature reaches 10°F
above zone temperature setpoint.
Single Zone Variable Air Volume
(SZVAV) Only
The IntelliPak controls platform supports Single ZoneVAV
as an optional unit control type in order to meet ASHRAE
90.1.The basic control is a hybrid VAV/CV configured unit
that provides discharge temperature control to a varying
discharge air temperature target setpoint based on the
space temperature and/or humidity conditions.
Concurrently, the unit will control and optimize the supply
fan speed to maintain the zone temperature to a zone
temperature setpoint.
Supply Fan VFD Control
Single Zone VAV units are equipped with a VFD-controlled
supply fan which is controlled via a 0-10VDC signal from
RT-SVX36K-EN
the Rooftop Module (RTM). With the RTM supply fan
output energized and the RTMVFD output at 0VDC, the fan
speed output is 37% from theVFD by default; and at 10VDC
the fan speed output is 100%.The control scales the VDC
output from the RTM linearly to control fan speed output
between 37-100%.The VFD will modulate the supply fan
motor speed, accelerating or decelerating as required to
maintain the zone temperature to the zone temperature
setpoint. When subjected to high ambient return
conditions the VFD will reduce its output frequency to
maintain operation. Bypass control is offered to provide
full nominal airflow in the event of drive failure.
Ventilation Control
Units configured for Single Zone VAV control require
special handling of the OA Damper Minimum Position
control in order to compensate for the non-linearity of
airflow associated with the variable supply fan speed and
damper combinations. Units configured forTRAQ with or
without DCV use the same sequence of operation as VAV
or CV units.
Space Pressure Control
For SZVAV units configured with or without Space
Pressure Control (StatiTrac), the Exhaust Enable Setpoint
(based on the outside air damper position) is used when
the Supply Fan is at 100%. ATarget setpoint is internally
calculated when the supply fan is at less than 100%. The
exhaust fan is allowed to start when theTarget setpoint is
reached. If the Exhaust Enable Setpoint is set to 0%, then
the exhaust fan will be allowed to start whenever the
Active Minimum position is reached regardless of supply
fan speed.
Occupied Cooling Operation
For normal cooling operation, cooling capacity will be
staged or modulated in order to meet the calculated
discharge air target setpoint. If the current active cooling
capacity is controlling the discharge air within the
deadband, no additional cooling capacity change will be
requested. As the Discharge AirTemperature rises above
the deadband, the algorithm will request additional
capacity as required (additional compressors or
economizer). As the Discharge AirTemperature falls below
the deadband, the algorithm will request a reduction in
active capacity.
Default Economizer Operation
By default, the unit will be setup to optimize the minimum
supply fan speed capability during Economizer Only
operation. If the economizer is able to meet the demand
alone, due to desirable ambient conditions, the supply fan
speed will be allowed to increase above the minimum
prior to utilizing mechanical cooling if discharge air
setpoint falls below the discharge air Lower Limit
(Cooling) setpoint.
General Information
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