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NOTE: All troubles are latched by the duct smoke detector. The
trouble condition must be cleared and then the duct smoke detec-
tor must be reset in order to restore it to the normal state.
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
controller. 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 sen-
sor 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 nec-
essary 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. 42. Repair or replace loose or missing wiring.
2.
Configure the sensor dirty test to activate the controller's
supervision relay. See "Dirty Sensor Test" on page 33.
SENSOR'S TROUBLE LED IS ON, BUT THE CONTROL-
LER'S TROUBLE LED IS OFF
Remove JMP1 on the controller.
PROTECTIVE DEVICES
Compressor Protection
OVERCURRENT
The compressor has internal line-break motor protection.
OVERTEMPERATURE
The compressor has an internal protector to protect it against ex-
cessively high discharge gas temperatures.
MIXED TEMPERATURE SENSOR
The Mixed Temperature Sensor (MTS) is installed on the return
side of the unit filter bracket. See Fig. 45.
The switch opens to prevent mechanical cooling operation at
low return temperatures (below 60°F [+/- 1.5°F]). When the
switch is open, compressor operation is disabled but indoor fan
and economizer operation may continue.
The switch closes when return air warms to 65°F (+/-1.5°F)
allowing compressor operation to resume.
Position capillary line in a circular
position in front of sensor.
Make sure that the capillary
and sensor are not
touching each other.
Evaporator
Filter Rack
Detailed view to show orientation
of attachment screws
Fig. 45 — Mixed Temperature Sensor Location
HIGH PRESSURE SWITCH
The 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).
35
Reference:
Back of
Control Box
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Troubleshooting
