Daikin DRG0361DL00001S, Инструкция по эксплуатации

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SERVICING
3. Check the temperature at which the control opens
its contacts by raising the temperature of the control.
The crankcase heater thermostat should open at 85°F
± 5°F.
4. If not as above, replace control.
S-21 Checking Reversing Valve And Solenoid
Occasionally the reversing valve may stick in the heating or
cooling position or in the mid-position.
When stuck in the mid-position, part of the discharge gas
from the compressor is directed back to the suction side,
resulting in excessively high suction pressure. An increase
in the suction line temperature through the reversing
valve can also be measured. Check operation of the valve
by starting the system and switching the operation from
COOLING to HEATING cycle.
If the valve fails to change its position, test the voltage
(24V) at the valve coil terminals, while the system is on the
COOLING cycle.
If no voltage is registered at the coil terminals, check the
operation of the thermostat and the continuity of the
connecting wiring from the “O” terminal of the thermostat
to the unit.
If voltage is registered at the coil, tap the valve body lightly
while switching the system from HEATING to COOLING,
etc. If this fails to cause the valve to switch positions,
remove the coil connector cap and test the continuity of
the reversing valve solenoid coil. If the coil does not test
continuous - replace it.
If the coil test continuous and 24 volts is present at the coil
terminals, the valve is inoperative - replace it.
S-24 Testing Defrost Control
To check the defrost control for proper sequencing,
proceed as follows: With power ON; unit not running.
1. Jumper defrost thermostat by placing a jumper wire
across the terminals “DFT” and “R” at defrost control
board.
2. Connect jumper across test pins on defrost control
board.
3. Set thermostat to call for heating. System should go
into defrost within 21 seconds.
4. Immediately remove jumper from test pins.
5. Using VOM check for voltage across terminals “C &
O”. Meter should read 24 volts.
6. Using VOM check for voltage across fan terminals DF1
and DF2 on the board. You should read line voltage
(208-230 VAC) indicating the relay is open in the
defrost mode.
7. Using VOM check for voltage across “W2 & C”
terminals on the board. You should read 24 volts.
8. If not as above, replace control board.
9. Set thermostat to off position and disconnect power
before removing any jumpers or wires.
NOTE: Remove jumper across defrost thermostat before
returning system to service.
S-25 Testing Defrost Thermostat
1. Install a thermocouple type temperature test lead on
the tube adjacent to the defrost control. Insulate the
lead point of contact.
2. Check the temperature at which the control closes its
contacts by lowering the temperature of the control.
On 3 thru 5 ton units, it should close at 31°F ± 3°F.
3. Check the temperature at which the control opens its
contacts by raising the temperature of the control. On
3 thru 5 ton units, it should open at 75°F ± 6°F.
4. If not as above, replace control.
TROUBLESHOOTING
THE FOLLOWING INFORMATION IS FOR USE BY QUALIFIED
SERVICE AGENCY ONLY: OTHERS SHOULD NOT ATTEMPT TO
SERVICE THIS EQUIPMENT.
Common Causes of Unsatisfactory Operation of Heat
Pump on the Heating Cycle.
Inadequate Air Volume Through Indoor Coil
When a heat pump is in the heating cycle, the indoor coil
is functioning as a condenser. The return air filter must
always be clean, and sufficient air volume must pass
through the indoor coil to prevent excessive discharge
pressure, and high pressure cut out.
Outside Air into Return Duct
Do not introduce cold outside air into the return duct of
a heat pump installation. For units with 2-speed motors,
do not allow air entering the indoor coil to drop below
65° F. Air below this temperature will cause low discharge
pressure, thus low suction pressure, and excessive defrost
cycling resulting in low heating output. It may also cause
false defrosting.