Table 14 — PARABLADE Economizer Troubleshooting
PROBLEM
CAUSE
REMEDY
Damper does not open.
Evaporator fan not on.
Check wiring between G on connection board and indoor (evaporator) fan
contactor.
No power to economizer
motor.
1. Disconnect power at TR and TR1. Disconnect jumper across P and P1.
2. Connect jumper across TR and 1.
3. Connect jumper across T1 and T.
4. If connected, remove enthalpy sensor from terminals S
O
and
1
.
5. Apply power (24 vac) to terminals TR and TR1. The LED should be off and
the damper should be in the closed position.
6. Disconnect the factory-installed 620 ohm resistor from terminals S
R
and
1
.
The LED should light up and the motor should drive towards open. If this
does not happen, replace the economizer control module.
Economizer motor
failure.
If the indoor (evaporator) fan and economizer motor are energized, verify that
there is a minimum of 24 vac at terminals TR and TR1. If the motor is not oper-
ating, replace the motor.
Economizer operation limited
to minimum position.
Economizer control mod-
ule failure.
1. To simulate high or low enthalpy, reconnect the factory-installed 620 ohm
resistor across terminals S
R
and
1
.
2. Connect 1.2 Kohm checkout resistor across terminals S
O
and
1
. Turn the
enthalpy set point to ‘‘A.’’ The LED should turn on, indicating low enthalpy.
The motor should drive towards open. If LED does not light, replace module.
If motor does not drive open, check motor operation.
3. Turn the enthalpy set point to ‘‘D.’’ The LED should turn off, indicating high
enthalpy. The motor should drive towards closed. If these actions do not oc-
cur, replace module.
4. Disconnect 1.2 Kohm checkout resistor before resuming operation.
Damper does not close.
No power to economizer.
1. Disconnect power at TR and TR1. Disconnect jumper across P and P1.
2. Connect jumper across TR and 1.
3. Connect jumper across T1 and T.
4. If connected, remove enthalpy sensor from terminals S
O
and
1
. Factory-
installed 620 ohm resistor should be connected to terminals S
R
and
1
.
5. Apply power (24 Vac) to terminals TR and TR1. The LED should be off and
the damper should be in the closed position.
6. Disconnect the factory-installed 620 ohm resistor from terminals S
R
and
1
.
The LED should light up and the motor should drive towards open. If this
does not happen, replace the economizer control module.
Spring return failure.
If power to unit is off and damper does not close, check for a bound linkage. If
linkage is not bound, then internal spring may be broken. Replace actuator.
Economizer motor
failure.
If the economizer control module is functioning properly, verify that there is a
minimum of 24 vac at terminals TR and TR1. If the motor is not operating, re-
place the motor.
Damper does not open
or close according
to enthalpy readings.
Sensor incorrectly wired or
bad.
To verify sensor operation, reconnect the
1
lead of the outdoor enthalpy sensor
to the
1
terminal of the economizer control module. Connect a DC milliammeter
between terminals S
O
of the economizer control module and terminal S of the
enthalpy sensor. The milliammeter should indicate between 3 and 25 mA if the
sensor is operating properly. If the milliammeter indicates 0, the sensor may be
wired backwards. If any other readings are shown, replace the sensor.
LED — Light-Emitting Diode
Copyright 1995 Carrier Corporation
Manufacturer reserves the right to discontinue, or change at any time, specifications or designs without notice and without incurring obligations.
Book 1
4
Tab
1b 6b
PC 111
Catalog No. 535-042
Printed in U.S.A.
Form 50GJ-1SI
Pg 34
4-95
Replaces: New
Содержание 50GJ006
Страница 30: ...Fig 37 Cooling Charging Chart 50GJ006 Fig 38 Cooling Charging Charts 50GJ008 30...
Страница 31: ...Fig 39 Cooling Charging Charts 50GJ012 31...
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