Nordyne R-410A Module Wiring Troubleshooting, OUTDOOR THERMOSTAT if supplied

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.

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.

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