Troubleshooting; Protective Devices; Compressor Protection - Carrier 50FC 04 Series Service And Maintenance Instructions

• If a sensor trouble, the sensor's Trouble LED the control-
ler's Trouble LED turn on.
• If 100% dirty, the sensor's Dirty LED turns on and the
controller's Trouble LED flashes continuously.
• If a wiring fault between a sensor and the controller, the
controller's Trouble LED turns on but not the sensor's.
Table 5 — Detector Indicators
CONTROL OR
INDICATOR
Resets the sensor when it is in the alarm or trouble
Magnetic test/
state. Activates or tests the sensor when it is in the
reset switch
normal state.
Alarm LED Indicates the sensor is in the alarm state.
Trouble LED Indicates the sensor is in the trouble state.
Indicates the amount of environmental
Dirty LED compensation used by the sensor (flashing
continuously = 100%)
Power LED Indicates the sensor is energized.
Alarm
Fig. 53 — Controller Assembly
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.
DESCRIPTION
Trouble
Power
POWER
TROUBLE
ALARM
RESET
Test/Reset
Switch
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. 51. 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 27.
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
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.
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).
LOW PRESSURE SWITCH
The 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).
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