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Table 2. Module Wiring Troubleshooting
for any unusual noises. If present, locate and
determine the source of the noise and correct
as necessary.
OUTDOOR THERMOSTAT (if supplied)
The outdoor thermostat prevents the electrical
auxiliary heat (if used) from operating above a
desired set point. Selection of the set point is
determined from the building design heat load.
The thermostat is adjustable from 45°F to 0°F.
The factory temperature setting is at 40°F.
Defrost Cycle Timer —
The defrost cycle timer
controls the time interval of the hot gas defrost
after the defrost sensor closes. It is located
in the lower left corner of the defrost control
board. Three interval settings are available: 30
minutes, 60 minutes, and 90 minutes. Time setting
selection is dependent on the climate where the
unit is being installed.
Example 1. Dry climate of Southern
Arizona. A 90 minute setting is
recommended.
Example 2. Moist climate of Seattle,
Washington. A 30 minute setting is
recommended.
To set the cycle timer, place the timing pin on
the defrost control board to the desired time
interval post.
Note:
All units are shipped from the factory with
the default time setting of 30 minutes. Maximum
heating performance can be achieved by setting
the time to 90 minutes.
Defrost Test Procedure
1.
Terminals “R”-”C” must have 18-30v present
between them in order for time delay and
defrost sequences to be initiated.
Miswired Module Indication
Recommended Troubleshooting Action
Green LED is not on,
Determine if both R and C module terminals are
module does not power up
connected. Verify voltage is present at module’s R and
C terminals. Review
24VAC Power W iring
(page 4) for
R and C wiring.
Green LED intermittent,
Determine if R and Y terminals are wired in reverse.
module powers up only
Verify module’s R and C terminals have a constant
when compressor runs
source. Review
24VAC Power W iring
(page 4) for R
and C wiring.
TRIP LED is on but system
Verify Y terminal is connected to 24VAC at contactor
and compressor check OK
coil. Verify voltage at contactor coil falls below 0.5VAC
when off. Verify 24 VAC is present across Y and C when
thermostat demand signal is present. If not, R and C are
reverse wired.
TRIP LED and ALERT LED
Verify R and C terminals are supplied with 19-28VAC.
flashing together
ALERT Flash Code 3
Verify Y terminal is connected to 24VAC at contactor coil.
(Compressor Short Cycling)
Verify voltage at contactor coil falls below 0.5VAC when
displayed incorrectly
off.
ALERT Flash Code 5, 6 or 7
Check that compressor run and start wires are through
(Open Circuit, Open Start Circuit
module’s current sensing holes. Verify Y terminal is
or Open Run Circuit) displayed
connected to 24VAC at contactor coil. Verify voltage at
incorrectly
contactor coil falls below 0.5VAC when off.
ALERT Flash Code 6 (Open
Check that compressor run and start wires are routed
Start Circuit) displayed for Code 7 through the correct module sensing holes.
(Open Run Circuit) or vice versa
ALERT Flash Code 8
Determine if module’s Y terminal is connected. Verify Y
(Welded Contactor)
terminal is connected to 24VAC at contactor coil. Verify
displayed incorrectly
24VAC is present across Y and C when thermostat demand
signal is present. If not, R and C are reverse wired. V erify
voltage at contactor coil falls below 0.5VAC when off.
Review
Thermostat Demand Wiring
(page 4) for Y and C
wiring.
