Special Functions; Refrigerant Collecting (Pump Down) - Mitsubishi Electric PUHZ-SHWHA Série Manuel D'installation

9. Special Functions

A
B
Fig. 9-1
A Circuit diagram example (low noise mode)
B On-site arrangement
C External input adapter (PAC-SC36NA-E)
X: Relay
A
B
Fig. 9-2
A Circuit diagram example (Demand function)
B On-site arrangement
C External input adapter (PAC-SC36NA-E)
X, Y: Relay

9.3. 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 min-
utes 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 op-
erating (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 min-
utes after the compressor stops, the refrigerant collecting operation cannot 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 valve on the gas pipe side of the outdoor unit when the pres-
sure gauge on the gauge manifold shows 0.05 to 0 MPa [Gauge] (approx. 0.5 to
0 kgf/cm ) and quickly stop the outdoor unit.
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* If the pump-down SWP switch is pushed again, the unit stops.
9.4 Setting the temperature of the ZUBADAN flash injection function
The ZUBADAN flash injection function achieves high heating performance at low outdoor temperatures.
• The SW9-3 and SW9-4 on the control board of the outdoor unit allow setting of the temperature available for the ZUBADAN flash injection function as shown in the below
table.
SW9-3 SW9-4
OFF OFF
OFF ON
ON OFF
ON ON
C D
Orange
Brown
Red
E
D Outdoor unit control board
E Max. 10 m
F Power supply for relay
C D
Orange
Brown
Red
E
D Outdoor unit control board
E Max. 10 m
F Power supply for relay
Outdoor temperature
3˚C or less (Default setting)
0˚C or less
–3˚C or less
–6˚C or less
9.1. Low noise mode (on-site modification) (Fig. 9-1)
By performing the following modification, 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 SW1 ON: Low noise mode
SW1 OFF: Normal operation
Note:
When the Dip SW7-1 and SW9-1 on the control board of the outdoor unit is
ON, set Dip SW7-1, SW9-1 to OFF. (This mode cannot be used together with
the demand function.)
9.2. Demand function (on-site modification) (Fig. 9-2)
(Only for Air-Conditioners)
By performing the following modification, energy consumption can be reduced to
0–100% of the normal consumption.
The demand function 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.
1 Complete the circuit as shown when using the external input adapter
(PAC-SC36NA-E). (Option)
2 By setting SW7-1 on the control board of the outdoor unit, the energy consump-
tion (compared to the normal consumption) can be limited as shown below.
SW7-1 SW2
OFF
ON
Demand
ON
function
ON
OFF
* 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 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 valve com-
pletely.)
* 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 re-
frigerant 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.
SW3 Energy consumption
OFF 100%
OFF 75%
ON 50%
ON 0% (Stop)
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