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7)
Startup–no component LEDs are on (LED 3 off for EvapFM operation):
There is a
5-second delay while CB identifies program revision. Revision (r###) is shown on DB.
After 5-second delay, DB shows current cabinet temperature and EvapFM energizes.
2.5 minute Comp delay timer starts.
Diagnosis:
Check that red "POWER OK" LED is
on. If not, verify incoming voltage supply. Check transformer input and output voltage
(115VAC input and 10VAC output voltage) and transformer continuity. If 115VAC input
and 10VAC output voltage is present, and the red "POWER OK" LED is off, CB is bad
and must be replaced. Check that EvapFM is running. If not, check EvapFM blade for
binding. Next, check for 115VAC at K1 connector pin #3 dark blue (DBU) to any white
(W) neutral wire. If 115VAC is not present, CB is bad and must be replaced. If 115VAC is
present, check EvapFM continuity.
8)
Cool-Down–LED 4 (Comp) and LED 5 (ConFM) are on:
EvapFM continues and
2.5 minute Comp delay timer terminates. Comp, ConFM, and PH energize (if PH switch
is in the on position (red marking visible)).
Comp
Circuit Diagnosis:
If Comp does not start, check for 115VAC at K1 connector
pin #10 gray (GY) wire to any white (W) neutral wire. If 115VAC is not present, CB is
bad and must be replaced. If 115VAC is present, check for 115VAC at Comp relay coil
gray (GY) wire to any white (W) neutral wire. If 115VAC is present, and Comp is not on,
check for 115VAC at Comp relay orange (O) wire to Comp relay red (R) wire. If 115VAC
is present, Comp relay is bad and must be replaced. If 115VAC is not present, check
for 115VAC at Comp relay red (R) wire to any white (W) neutral wire. If 115VAC is not
present, electronic unit is bad and must be replaced. If 115VAC is present, and Comp
is not on, remove the electronic unit to access Comp terminals. Next, check for 80VAC
from each Comp terminal to ground. If 80VAC is not present, electronic unit is bad and
must be replaced. If 80VAC is present, check Comp continuity.
ConFM
Diagnosis:
If ConFM does not start, check that the fan blade is not binding.
Next, check for 115VAC at red K9 connector pin #2 brown (BR) to any white (W) neutral
wire. If 115VAC is not present, CB is bad and must be replaced. If 115VAC is present,
check ConFM continuity.
If Comp and CondFM are on and the cabinet temperature is not dropping, check for
a restriction in the refrigeration circuit, correct TXV operation, and correct refrigerant
charge.
PH
Diagnosis:
Comp
must be energized when troubleshooting PH. Confirm PH switch
is on (red marking visible). Next, check for voltage at PH switch. 115VAC should be
present from both black (BK) wires to any white (W) neutral wire. If 115VAC is present
on one and not the other, the PH switch is open. Confirm 115VAC at the PH relay coil.
Next, check for 115VAC from both black (BK) wires at the PH relay to any white (W)
neutral wire. If 115VAC is present on one and not the other, the PH relay contacts are
open. Check PH amp draw, if no amp draw is present, check the continuity of the PH.
