Ingersol Rand Precedent TSC120F Series, Сервисные данные

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Sequence of Operation
RT-SVF28F-EN 15
starts a 20-second pre-purge (15 seconds on high speed
followed by 5 seconds on low speed). If the pressure
switch (PS) is still open, the inducer blower will continue to
be energized on high speed until pressure switch closure.
After pre-purge completes, the (IGN) energizes the first
stage of the gas valve, initiates spark for 2 seconds
minimum, 7 seconds maximum (ignition trial) and detects
flame and de-energizes spark. From this point, a fixed 45
second indoor blower delay on timing starts. After the
indoor blower delay on is completed, the (IGN) energizes
the indoor blower. The (IGN) enters a normal operating
loop where all inputs are continuously monitored. If the
first stage of gas heat can not satisfy the heating
requirement, the thermostat closes W2. The (IGN)
energizes the second stage of the gas valve and the second
stage of inducer blower. When the zone thermostat is
satisfied, the (IGN) de-energizes the gas valve. The (IGN)
senses loss of flame.The (IGN) initiates a 5 second inducer
blower post purge. The (RTRM) initiates a second indoor
blower delay off.
If the burner fails to ignite, the ignition module will attempt
two retries before locking out.The green LED will indicate
a lock out by two fast flashes. An ignition lockout can be
reset by;
1. Opening for 3 seconds and closing the main power
disconnect switch.
2. Switching the “Mode” switch on the zone sensor to
“OFF” and then to the desired position.
3. Allowing the ignition control module to reset
automatically after one hour. Refer to the “Ignition
Control Module Diagnostics” section for the LED
diagnostic definitions.
When the fan selection switch is set to the “Auto” position,
the RTRM energizes the indoor fan relay (F) coil
approximately 30 second after initiating the heating cycle
to start the indoor fan motor (IDM).
Drain Pan Condensate Overflow Switch
(Optional)
This input incorporates the Condensate Overflow Switch
(COF) mounted on the drain pan and the ReliaTel Options
Module (RTOM). When the condensate level reaches the
trip point for 6 continuous seconds, the RTOM will shut
down all unit function until the overflow condition has
cleared. The unit will return to normal operation after 6
continuous seconds with the COF in a non-tripped
condition. If the condensate level causes the unit to
shutdown more than 2 times in a 3 day period, the unit will
be locked-out of operation. A manual reset of the
diagnostic system through the zone sensor or Building
Automation System (BAS) will be required. Cycling unit
power will also clear the fault.
VAV Units Only-Sequence of
Operation
Supply Air Pressure Control
ReliaTel Option Module Control (RTOM)
Supply fan is driven by a pulse-width modulation (PWM)
signal from the RTOM. A pressure transducer measures
duct static pressure, and the supply fan is modulated to
maintain the supply air static pressure within an
adjustable user-defined range.The range is determined by
the supply air pressure setpoint and supply air pressure
deadband, which are set through a unit mounted
potentiometer. The RTOM provides supply fan motor
speed modulation.
The supply fan will accelerate or decelerate as required to
maintain the supply static pressure setpoint.
Supply Air Static Pressure Limit
The control of the supply fan and VAV boxes are
coordinated, with respect to time, during unit start up and
transition to/from Occupied/Unoccupied modes to
prevent overpressurization of the supply air ductwork.
However, if for any reason the supply air pressure exceeds
the fixed supply air static pressure limit of 3.5" W.C., the
supply fan is shut down and the VAV boxes are closed.The
unit is then allowed to restart three times. If the
overpressurization condition occurs on the fourth time,
the unit is shut down and a manual reset diagnostic is set
and displayed at any of the remote panels with LED status
lights or communicated to the Integrated Comfort system.
Supply Air Temperature Controls
Cooling/Economizer
During occupied cooling mode of operation, the
economizer (if available) and primary cooling are used to
control the supply air temperature. The supply air
temperature setpoint is user-defined at the unit mounted
VAV Setpoint Potentiometer or at the remote panel. If the
enthalpy of the outside air is appropriate to use "free
Table 19. Ignition module diagnostics
Steady light
Module is powered up, but no active call for
heat.
Blinking at
continuous
steady rate
Active call for heat.
One blink
Loss of communication.
Two blinks
System lockout (failure to ignite, no spark, low/
no gas pressure, etc.)
Three blinks
Pressure switch (no vent air flow, bad CBM,
closed at initial call for heat). Auto reset.
Four blinks
High limit (excessive heat in combustion
chamber, low airflow). Auto reset.
Five blinks
Flame sensed and gas valve not energized or
flame sensed and no call for heat.
Six blinks
Flame rollout (CBM failure, incorrect gas
pressure, incorrect primary air). Requires
manual reset of the switch.
Seven blinks
ReliaTel module will communicate a heat fail
diagnostic back to the RTRM.