Mitsubishi Electric CRHV-P600YA-HPB Service Handbook page 101

[ VII Control ]
Control Method
-10- Automatic operation of pump for freeze-up protection
1. Purpose
This is a function to protect the water circuit from freezing up in winter.
2. Pump wire connection
yellow
CN512
7 6 5 4 3 2
3. Natural freeze-up protection
The units will operate according to the dip switch SW2-1 on the control board as shown in the table below.
Dip switch settings
Control method
Hot water side
Heat source side
HWE1312A
blue
CN511 CN510
1 7 6 5 4 3 2 1 7 6 5 4 3 2
77 76 75 74 73 72 71
No-voltage contact output
Pump start conditions
Pump stop conditions
Pump start conditions
Pump stop conditions
MB Transmission cable for multiple unit control
Measurement terminal for maintenance(M-NET)
MA
TB6
CN52C
52C
red
1
PL2
Pump error
70
(heat source)
TB8
PL1
Pump error
(hot water)
F2
ELB2
SW2-1 OFF
Natural freeze-up protection based on the water temperature
Hot water temperature is within
±1ºC of 3 ºC
Hot water temperature is more than
±1ºC of 5 ºC
Heat source temperature is more
than ±1ºC of -8 ºC
Heat source temperature is more
than ±1ºC of -6 ºC
- 94 -
B
TO SUB BOX TB3
A
M M
MP1 MP2
3 3
~ ~
52P1 52P2
52P1
52P2
power supply
3N~
50Hz
L1 L2 L3 N
380/400/415V
SW2-1 ON
Same as left
Same as left
Same as left
Same as left
GB