Special Functions - Mitsubishi Electric PUD-SWM60VAA-BS Service Manual

SPECIAL FUNCTIONS

9.7.1. Low noise mode (on-site modification) (Fig. 9-7-1)
1. Using the CNDM connector (Option)
By performing the following modification, operation noise of the outdoor unit can be
reduced.
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
2. Using remote controller
Refer to the indoor unit installation manual.
9.7.2. Demand function (on-site modification) (Fig. 9-7-2)
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 consumption
(compared to the normal consumption) can be limited as shown below.
SW7-1 SW2
OFF
ON
Demand
ON
function
ON
OFF
9.7.3. 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 displayed,
the refrigerant collecting (pump down) cannot be completed normally.
• Startup of the indoor-outdoor communication takes about 3 minutes after the power (circuit breaker) is turned on. Start the pump-down opera-
tion 3 to 4 minutes after the power (circuit breaker) is turned ON.
• In the case of multi-units control, before powering on, disconnect the wiring
between the master indoor unit and the slave indoor unit. For more details
refer to the installation manual for the indoor unit.
2 After the liquid stop valve is closed, set the SWP switch on the control board of the outdoor unit to ON. The compressor (outdoor unit) and venti-
lators (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. However, even if the unit is stopped and the SWP switch is set to
ON less than 3 minutes after the compressor stops, the refrigerant collecting operation cannot be performed. Wait until compressor has been
stopped for 3 minutes and then set the SWP switch to ON again.
3 Because the unit automatically stops in about 2 to 3 minutes when the refrigerant collecting operation is completed (LED1 off, LED2 lit), be sure
to quickly close the gas stop valve. If LED1 is lit and LED2 is off and the outdoor unit is stopped, refrigerant collection is not properly performed.
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 off, LED2 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 extension piping is very long with large refrigerant amount, it may not be possible 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).
WARNING:
When pumping down the refrigerant, stop the compressor before disconnecting the refrigerant pipes.
The compressor may burst if air etc. get into it.
OCH694A
SW3 Energy consumption
OFF 100%
OFF 75%
ON 50%
ON 0% (Stop)
49
A
X
X
F
SW1
B
A Circuit diagram example
(low noise mode)
B On-site arrangement
C External input adapter
(PAC-SC36NA-E)
X: Relay
A
X Y
X
F
SW2
SW3
Y
B
A Circuit diagram example
(Demand function)
B On-site arrangement
X, Y: Relay
C D
CNDM
Orange
1
Brown
Red
3
Fig. 9-7-1
E
D Outdoor unit control board
E Max. 10 m
F Power supply for relay
C D
CNDM
Orange
1
Brown
Red
3
Fig. 9-7-2
E
C External input adapter
(PAC-SC36NA-E)
D Outdoor unit control board
E Max. 10 m
F Power supply for relay