Nordyne Two Stage R-410A Split System User's Information/Installation Instructions page 11

Status LED Status LED Description
Yellow "ALERT" Open Circuit
Flash Code 5
Yellow "ALERT" Open Start Circuit
Flash Code 6 Current only in run circuit
Yellow "ALERT" Open Run Circuit
Flash Code 7 Current only in start circuit
Yellow "ALERT" Welded Contactor
Flash Code 8 Compressor always runs
Yellow "ALERT" Low Voltage
Flash Code 9 Control circuit < 17VAC
•
Flash Code number corresponds to a number of LED flashes, followed by a pause and then repeated.
•
TRIP and ALERT LEDs flashing at same time means control circuit voltage is too low for operation.
Table 1. Interpreting the Diagnostic LEDS (Cont.)
temperature and ambient temperature. It provides
user selectable defrost termination temperature
(50 °F - 80 °F coil temperature).
Control is uncalibrated when power is applied.
Calibration occurs after a defrost cycle. The
control initiates this sacrifi cial defrost after 34
minutes of accumulated compressor run time
in heating with coil temperature below 35 °F.
The cycle terminates if coil sensor reaches
selected termination temperature or after 14
minutes defrost.
Defrost function is disabled if coil temperature
is above 35 °F. If Ambient sensor is detected as
open or shorted, demand defrost will not operate
and control will revert to time/temperature defrost
operation. If the outdoor coil sensor is detected
as open or shorted, the control will not perform
demand or time/temperature defrost operation.
Status LED Troubleshooting Information
1. Outdoor unit power disconnect is open
2. Compressor circuit breaker or fuse(s) is open
3. Compressor contactor has failed open
• Check compressor contactor wiring and connectors
• Check for compressor contactor failure (burned, pitted or
open)
• Check wiring and connectors between supply and
compressor
• Check for low pilot voltage at compressor contactor coil
4. High pressure switch is open and requires manual reset
5. Open circuit in compressor supply wiring or connections
6. Unusually long compressor protector reset time due to
extreme ambient temperature
7. Compressor windings are damaged
• Check compressor motor winding resistance
1. Run capacitor has failed
2. Open circuit in compressor start wiring or connections
• Check wiring and connectors between supply and the
compressor "S" terminal
3. Compressor start winding is damaged
• Check compressor motor winding resistance
1. Open circuit in compressor run wiring or connections
• Check wiring and connectors between supply and the
compressor "R" terminal
2. Compressor run winding is damaged
• Check compressor motor winding resistance
1. Compressor contactor has failed closed
2. Thermostat demand signal not connected to module
1. Control circuit transformer is overloaded
2. Low line voltage (contact utility if voltage at disconnect is low)
• Check wiring connections
Please note that when the defrost cycle initiates,
there will be a 30 second compressor delay
going into and out of the defrost cycle. This delay
may be removed by removing P6 connector on
the board.
This 2-stage unit will defrost in second stage
regardless of the stage called for by the
thermostat.
Diagnostic Description
Control Fault (No Power)
Normal Operation
ASCD Delay Active
(with compressor demand)
Low Pressure Switch Lockout
High Pressure Switch Lockout
Ambient Sensor Fault
Coil Sensor Fault
Table 2. Control Diagnostic
LED Status
Off
On
1 Flash
2 Flashes
3 Flashes
4 Flashes
5 Flashes
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