Carrier 50TCA04-A07 User Manual

Page 20

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20

S

If a wiring fault between a sensor and the controller, the
controller’s Trouble LED turns on but not the sensor’s.

Alarm

Power

Test/reset
switch

Trouble

C07298

Fig. 26 -- Controller Assembly

NOTE:

All troubles are latched by the duct smoke

detector. The trouble condition must be cleared and then
the duct smoke detector 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 Normal 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

reset 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 controller’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, de-

termine the cause and make the necessary repairs.

2. Check the wiring between the sensor and the control-

ler. 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, se-

cure 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, de-

termine why the controller does not have power and

make the necessary repairs.

2. Check the wiring between the sensor and the control-

ler. 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 control-

ler 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 re-

pair 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. 23. Repair or replace loose or missing wiring.

2. Configure the sensor dirty test to activate the control-

ler’s supervision relay. See “Changing sensor dirty

test operation.”

Sensor’s Trouble LED is On, But the Controller’s

Trouble LED is OFF

Remove JP1 on the controller.

PROTECTIVE DEVICES

Compressor Protection

Overcurrent
The compressor has internal linebreak motor protection.
Overtemperature
The compressor has an internal protector to protect it

against excessively 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

evaporator 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

overcurrent and overtemperature protection. Protection

devices reset automatically.

50TC

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