Checking Fan Relay Contacts - Goodman GPH13 Service Instructions Manual

SERVICING
VOLT/OHM
METER
Ohmmeter for testing holding coil
Voltmeter for testing contacts
TESTING COMPRESSOR CONTACTOR
(Three-phase)
S-9 CHECKING FAN RELAY CONTACTS
The Electronic Blower Time Delay Relay is used on the PSC
equipped, single phase models.
WARNING
Checking EBTDR High Voltage Contacts
1. With power off, remove wires from terminals NC, COM, and
NO.
2. Using a VOM, check for resistance from NO to COM. Should
read open. Next, check for resistance from NC to COM.
Should read closed.
3. If not as above, replace EBTDR.
Checking EBTDR Contact Operation
With power on:
WARNING
LINE VOLTAGE NOW PRESENT.
1. Set the thermostat to the fan "on" position.
2. Check for 24 volts at the C and G terminals of the EBTDR.
3. If no voltage present, check fan circuit from thermostat. If
24 volts present, proceed to step 4.
4. Using a VOM, check for line voltage from the purple wire at
the transformer (terminal 3 on 240 volt units, terminal 2 on
208 volt units) to terminal NO on the EBTDR. Should read
line voltage. If no voltage present, check line voltage wiring
in unit. If line voltage present, proceed to step 5.
28
T3 T2 T1
CC
L3 L2 L1
5. Using a VOM, check for line voltage from the purple wire at
the transformer (terminal 3 on 240 volt units, terminal 2 on
208 volt units) to the COM terminal on the EBTDR. Should
read line voltage. If not as above, replace EBTDR.
PSC equipped, single phase model coolers and heat pumps
have an isolation relay with a 240 volt holding coil in addition to
the EBTDR.
WARNING
DISCONNECT POWER SUPPLY BEFORE SERVICING.
Turn power off.
Testing relay holding coil
1. Remove the leads from the holding coil terminals 1 and 3.
2. Using an ohmmeter, test across the coil terminals 1 and 3.
If the coil does not test continuous, replace the relay.
Testing relay contacts
WARNING
DISCONNECT POWER SUPPLY BEFORE SERVICING.
Turn power off.
1. Using a VOM, test resistance across relay terminals 2 and
4. Should read open.
2. Turn power on.
WARNING
LINE VOLTAGE NOW PRESENT.
3. Apply 240 volts to coil terminals 1 and 3.
4. Using a VOM, check for 240 volts from terminals 3 and 1 of
relay. Should read 240 volts. In no voltage, check wiring
from heater kit to relay. If voltage present, proceed to step
5.
5. Using a VOM, check for 240 volts from L1 at contactor to
terminal 4 of relay. Should read 240 volts. Next check from
L1 at contactor to terminal 2 of relay. Should read 240
volts.
If not as above, replace relay.
On the 5 ton units with the GE X13
relay is used.
motor, a standard fan
TM