Special Functions - DeDietrich AWHP 4 MR Installation Manual

7. Special functions

A
X
X
SW1
A Circuit diagram example (low noise mode)
B On-site arrangement
C External input adapter (PAC-SC36NA-E)
X: Relay
7.2. Refrigerant collecting (pump down)
When relocating or disposing of the indoor/outdoor unit, pump down the system fol-
lowing the procedure below so that no refrigerant is released into the atmosphere.
1 Turn off the power supply (circuit breaker).
2 Connect the low-pressure valve on the gauge manifold to the charge plug (low-
pressure side) on the outdoor unit.
3 Close the liquid stop valve completely.
4 Supply power (circuit breaker).
* When power is supplied, make sure that "CENTRALLY CONTROLLED" is not
displayed on the remote controller. If "CENTRALLY CONTROLLED" is dis-
played, the refrigerant collecting (pump down) cannot be completed normally.
* Start-up of the indoor-outdoor communication takes about 3 minutes after the
power (circuit breaker) is turned on. Start the pump-down operation 3 to 4
minutes after the power (circuit breaker) is turned on.
5 Perform the refrigerant collecting operation (cooling test run).
* Push the pump-down SWP switch (push-button type) on the control board of
the outdoor unit. The compressor and ventilators (indoor and outdoor units)
start operating (refrigerant collecting operation begins). (LED1 and LED2 on
the control board of the outdoor unit are lit.)
* Only push the pump-down SWP switch if the unit is stopped. However, even
if the unit is stopped and the pump-down SWP switch is pushed less than 3
minutes after the compressor stops, the refrigerant collecting operation can-
not be performed. Wait until the compressor has been stopped for 3 minutes
and then push the pump-down SWP switch again.
6 Fully close the ball/stop valve on the gas pipe side of the outdoor unit when the
pressure gauge on the gauge manifold shows 0.05 to 0 MPa [Gauge] (approx. 0.5
to 0 kgf/cm ) and quickly stop the air conditioner.
2
C D
CNDM
Orange
1
Brown
Fig. 7-1
Red
3
D Outdoor unit control board
E Max. 10 m
F Power supply for relay
7.1. Low noise mode (on-site modifi cation) (Fig. 7-1)
By performing the following modifi cation, operation noise of the outdoor unit can be
reduced by about 3-4 dB.
The low noise mode will be activated when a commercially available timer or the
contact input of an ON/OFF switch is added to the CNDM connector (option) on the
control board of the outdoor unit.
• The ability varies according to the outdoor temperature and conditions, etc.
1 Complete the circuit as shown when using the external input adapter
(PAC-SC36NA-E). (Option)
2 SW7-1 (Outdoor unit control board): OFF
3 SW1 ON: Low noise mode
SW1 OFF: Normal operation
* If the pump-down SWP switch is pushed again, the unit stops.
* Because the unit automatically stops in about 3 minutes when the
refrigerant collecting operation is completed (LED1 off, LED2 lit), be sure to
quickly close the gas ball/stop valve. However, if LED1 is lit, LED2 is off, and
the unit is stopped, open the liquid stop valve completely, close the valve
completely after 3 minutes or more have passed, and then repeat step 5.
(Open the gas ball/stop valve completely.)
* If the refrigerant collecting operation has been completed normally (LED1 off,
LED2 lit), the unit will remain stopped until the power supply is turned off.
* Note that when the extension piping is very long with a large refrigerant
amount, it may not be possible to perform a pump-down operation. In this
case, use refrigerant recovery equipment to collect all of the refrigerant in the
system.
7 Turn off the power supply (circuit breaker), remove the gauge manifold, and then
disconnect the refrigerant pipes.
Warning:
When pumping down the refrigerant, stop the compressor before disconnect-
ing the refrigerant pipes.
• If the refrigerant pipes are disconnected while the compressor is operat-
ing and the stop valve (ball valve) is open, the pressure in the refrigeration
cycle could become extremely high if air is drawn in, causing the pipes to
burst, personal injury, etc.
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