21
Resetting Alarm and Trouble Condition Trips
Manual reset is required to restore smoke detector systems to Nor-
mal operation. For installations using two sensors, the duct smoke
detector does not differentiate which sensor signals an alarm or
trouble condition. Check each sensor for Alarm or Trouble status
(indicated by LED). Clear the condition that has generated the trip
at this sensor. Then reset the sensor by pressing and holding the re-
set button (on the side) for 2 seconds. Verify that the sensor’s
Alarm and Trouble LEDs are now off. At the controller, clear its
Alarm or Trouble state by pressing and holding the manual reset
button (on the front cover) for 2 seconds. Verify that the control-
ler’s Alarm and Trouble LEDs are now off. Replace all panels.
Troubleshooting
CONTROLLER’S TROUBLE LED IS ON
1. Check the Trouble LED on each sensor connected to the con-
troller. If a sensor’s Trouble LED is on, determine the cause
and make the necessary repairs.
2. Check the wiring between the sensor and the controller. If
wiring is loose or missing, repair or replace as required.
CONTROLLER’S TROUBLE LED IS FLASHING
1. One or both of the sensors is 100% dirty.
2. Determine which Dirty LED is flashing then clean that sensor
assembly as described in the detector cleaning section.
SENSOR’S TROUBLE LED IS ON
1. Check the sensor’s Dirty LED. If it is flashing, the sensor is
dirty and must be cleaned.
2. Check the sensor’s cover. If it is loose or missing, secure the
cover to the sensor housing.
3. Replace sensor assembly.
SENSOR’S POWER LED IS OFF
1. Check the controller’s Power LED. If it is off, determine why
the controller does not have power and make the necessary
repairs.
2. Check the wiring between the sensor and the controller. If
wiring is loose or missing, repair or replace as required.
CONTROLLER’S POWER LED IS OFF
1. Make sure the circuit supplying power to the controller is
operational. If not, make sure JP2 and JP3 are set correctly on
the controller before applying power.
2. Verify that power is applied to the controller’s supply input
terminals. If power is not present, replace or repair wiring as
required.
REMOTE TEST/RESET STATION’S TROUBLE LED DOES
NOT FLASH WHEN PERFORMING A DIRTY TEST, BUT
THE CONTROLLER’S TROUBLE LED DOES
1. Verify that the remote test/station is wired as shown in
Fig. 27. Repair or replace loose or missing wiring.
2. Configure the sensor dirty test to activate the controller’s
supervision relay. See “Changing sensor dirty test operation.”
SENSOR’S TROUBLE LED IS ON, BUT THE CONTROL-
LER’S TROUBLE LED IS OFF
Remove JP1 on the controller.
PROTECTIVE DEVICES
Compressor Protection
OVERCURRENT
Each compressor has internal linebreak motor protection. Reset is
automatic after compressor motor has cooled.
OVERTEMPERATURE
Each compressor has an internal protector to protect it against ex-
cessively high discharge gas temperatures. Reset is automatic.
HIGH PRESSURE SWITCH
Each system is provided with a high pressure switch mounted on
the discharge line. The switch is stem-mounted and brazed into the
discharge tube. Trip setting is 630 psig ± 10 psig (4344 ± 69 kPa)
when hot. Reset is automatic at 505 psig (3482 kPa).
LOW PRESSURE SWITCH
Each system is protected against a loss of charge and low evapora-
tor coil loading condition by a low pressure switch located on the
suction line near the compressor. The switch is stem-mounted.
Trip setting is 54 psig ± 5 psig (372 ± 34 kPa). Reset is automatic
at 117 ± 5 psig (807 ± 34 kPa).
EVAPORATOR FREEZE PROTECTION
The system is protected against evaporator coil frosting and low
temperature conditions by a temperature switch mounted on the
evaporator coil hairpin. Trip setting is 30°F ± 5°F (–1°C ± 3°C).
Reset is automatic at 45°F (7°C).
Supply (Indoor) Fan Motor Protection
Disconnect and lockout power when servicing fan motor.
The standard supply fan motor is equipped with internal over-
current and overtemperature protection. Protection devices reset
automatically.
The High Static option supply fan motor is equipped with a pilot-
circuit Thermix combination overtemperature/overcurrent protec-
tion device. This device resets automatically. Do not bypass this
switch to correct trouble. Determine the cause and correct it.
CONDENSER FAN MOTOR PROTECTION
The condenser fan motor is internally protected against
overtemperature.
Relief Device
A soft solder joint at the suction service access port provides pres-
sure relief under abnormal temperature and pressure conditions
(i.e., fire in building). Protect this joint during brazing operations
near this joint.
Control Circuit, 24-V
The control circuit is protected against overcurrent conditions by a
circuit breaker mounted on control transformer TRAN. Reset is
manual.
GAS HEATING SYSTEM
General
The heat exchanger system consists of a gas valve feeding multi-
ple inshot burners off a manifold. The burners fire into matching
primary tubes. The primary tubes discharge into combustion ple-
num where gas flow converges into secondary tubes. The second-
ary tubes exit into the induced draft fan wheel inlet. The induced
fan wheel discharges into a flue passage and flue gases exit out a
flue hood on the side of the unit. The induced draft fan motor in-
cludes a Hall Effect sensor circuit that confirms adequate wheel
speed via the Integrated Gas Control (IGC) board. Safety switches
include a Rollout Switch (at the top of the burner compartment)
and a limit switch (mounted through the fan deck, over the tubes).
(See Fig. 30 and 31.)
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