Справочник Пользователя для Nordyne R-410A

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verify system operation and compatibility with the 
heat pump. Refer to the installation instructions 
for this equipment and perform a functional 
checkout in accordance with the manufacturer’s 
instructions.

Indoor Blower
1.  Turn the fan mode to ON. Verify that the 

indoor blower is operating and that airfl ow is 
not restricted.

2.  Set the fan mode back to AUTO. Blower will 

operate at a decreased speed on continuous 
fan.

Short Cycle Protection
1.   With the system operating in COOLING mode, 

record the setpoint temperature setting of the 
thermostat.

2.  Gradually raise the setpoint temperature 

until the outdoor unit and indoor blower de-
energize.

3.   Immediately lower the setpoint temperature of 

the thermostat to its original setting and verify 
that the indoor blower is energized and that 
the outdoor unit remains de-energized.

4.  After approximately 3 minutes, verify that the 

outdoor unit energizes and the temperature 
of the air supplied to the facility is cooler than 
ambient temperature.

Defrost Cycle Control
The defrost cycle is controlled by an Adaptive 
Demand Defrost algorithm that monitors coil 
temperature and ambient temperature. Other 
features of the of the demand defrost board 
include:
•  4 Field selectable defrost termination 

temperatures (50° F - 80° F coil temperature).

•  Field selectable compressor delay feature.
•  High pressure and low pressure switches.
•  Sensing of second stage compressor demand.
•  Test/speed up capability.
•  Anti short cycle timer (3 minutes) for 

compressor protection.

•  On board diagnostics with fl ashing LED for 

quicker troubleshooting. See Table 2.

Control Fault (No Power)

Off

Normal Operation

On

ASCD Delay Active
(with compressor demand)

1 Flash

Low Pressure Switch Lockout

2 Flashes

High Pressure Switch Lockout

3 Flashes

Ambient Sensor Fault

4 Flashes

Coil Sensor Fault

5 Flashes

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 
defrost 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.
NOTE: 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.

NOTE: All units are shipped from the factory with 
the default termination temperature set at 70° F.

Defrost Test  Procedure
1. Terminals R - C must have 18-30VAC present 

between them in order for defrost sequences 
to be initiated.

2  With heat mode thermostat demand (Y 

connected to R), short and hold the TEST 
pins together. This will energize reversing 
valve to initiate a forced defrost. NOTE: This 
will bypass the ASCD and allow the high stage 
compressor to come on immediately (if the 
REMOVE FOR NO DELAY jumper at P6 is 
removed). If the REMOVE FOR NO DELAY 
jumper at P6 is installed, the compressor will 
energize immediately following a 30-second 
delay.

3.  Remove the short on the TEST pins.

•  If the Coil temperature is above the Terminate 

Temperature selection setting, the defrost 
cycle will be terminated (reversing valve will 
de-energized).

•  If the coil temperature is below the Terminate 

Temperature election setting, the defrost 
cycle will continue for 14 minutes or until the 
coil temperature rises above the Terminate 
Temperature selection setting. NOTE: Short 
the TEST pins for 1 second or more to force 
the control out of defrost and back to heating 
mode (reversing valve de-energized). 
Compressor will turn on immediately (if 
the REMOVE FOR NO DELAY jumper is 
removed).