System With Two Refrigerant Circuits - Mitsubishi Electric PU(H)Y-P250YGM-A Service Handbook

[ II Restrictions ]

2. System with two refrigerant circuits

1. Assign the sequential number to the indoor units.
2. Do not connect the terminal blocks (TB5) on the indoor unit-
sthat are connected to different outdoor units with each oth-
er.
3. Replacement of male power supply switch connector(CN41)
must be performed only on one of the outdoor units.
4. Provide grounding to S terminal on the terminal block for-
transmission line for centralized control (TB7) on only one
ofthe outdoor units.
5. When the power supply unit is connected to the transmis-
sion line for centralized control, leave the male connector on
the female power supply switch connector (CN41) as it is.
(Factory setting)
Sample control wiring
L1
CN40
CN41
OC
Replace
51
TB7 TB3 TB5-1
M1M2S M1M2
A1 B1 S
TB15
Connect
Leave the male
connector on
CN41 as it is.
OC
52
TB5-2
TB7 TB3
M1M2 S M1M2 A2 B2S
NO
L2
Notes
IC
01
*Two indoor controllers (controller circuit boards)
are equipped in the indoor unit (P500).
1 2
A B
NO
MA
02
(1) Indoor/outdoor transmission line
Maximum distance (1.25mm
L1, L2 200m
(2) Transmission line for centralized control
Maximum line distance via outdoor unit
2
(1.25mm
L1+L31+L2
- 24 -
Maximum allowable length
2
or larger)
or larger)
500m