Special Functions; Refrigerant Collecting (Pump Down) - Mitsubishi Electric Mr.SLIM PUHZ-HRP71HA2 Manuel D'installation

9. Special Functions

A
X
X
SW1
Fig. 9-1
A Circuit diagram example (low noise mode)
B On-site arrangement
C External input adapter (PAC-SC36NA)
X: Relay
A
Y
SW2
Y
Fig. 9-2
A Circuit diagram example (Demand function)
B On-site arrangement
C External input adapter (PAC-SC36NA)
Y: Relay

9.3. Refrigerant collecting (pump down)

Perform the following procedures to collect the refrigerant when moving the indoor
unit or the outdoor unit.
1 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.
2 After the gas stop valve is closed, set the SWP switch on the control board of the
outdoor unit to ON. The compressor (outdoor unit) and ventilators (indoor and
outdoor units) start operating and refrigerant collecting operation begins. LED1
and LED2 on the control board of the outdoor unit are lit.
* Only set the SWP switch (push-button type) to ON if the unit is stopped. How-
ever, even if the unit is stopped and the SWP switch is set to ON less than
three minutes after the compressor stops, the refrigerant collecting operation
cannot be performed. Wait until compressor has been stopped for three min-
utes and then set the SWP switch to ON again.
9.4 Setting the temperature of the ZUBADAN fl ash injection function
The ZUBADAN fl ash 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 fl ash injection function as shown in the below
table.
SW9-3 SW9-4
OFF OFF
OFF ON
ON OFF
ON ON
12
C D
CNDM
Orange
1
Brown
Red
3
D Outdoor unit control board
E Max. 10 m
F Power supply for relay
C D
CNDM
Orange
1
Brown
Red
3
D Outdoor unit control board
E Max. 10 m
F Power supply for relay
Outdoor temperatures
≤ 3˚C (Initial setting)
≤ 0˚C
≤ –3˚C
≤ –6˚C
9.1. Low noise mode (on-site modifi cation) (Fig. 9-1)
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). (Option)
2 SW1 ON: Low noise mode
SW1 OFF: Normal operation
Note:
When the Dip SW9-1 on the control board of the outdoor unit is ON, set Dip
SW9-1 to OFF.
9.2. Demand function (on-site modifi cation) (Fig. 9-2)
By performing the following modifi cation, 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). (Option)
2 By setting SW7-1 and SW7-2 on the control board of the outdoor unit, the ener-
gy consumption (compared to the normal consumption) can be limited as shown
below.
SW7-1 SW7-2
OFF OFF
ON OFF
OFF ON
3 Because the unit automatically stops in about 2 to 3 minutes after the refrigerant
collecting operation (LED1 and LED2 are lit), be sure to quickly close the gas
stop valve. When LED1 and LED2 are lit and the outdoor unit is stopped, open
the liquid stop valve completely, and then repeat step 2 after 3 minutes have
passed.
* If the refrigerant collecting operation has been completed normally (LED1 and
LED2 are lit), the unit will remain stopped until the power supply is turned off.
4 Turn off the power supply (circuit breaker).
* Note that when the length of the extension piping is long, it may not be pos-
sible to perform a pump-down operation. When performing the pump-down
operation, make sure that the low pressure is lowered to near 0 MPa (gauge).
Energy consumption (SW2 ON)
0% (Stop)
50%
75%