Mitsubishi Electric CITY MULTI PUHY-P108 Service Handbook page 39

[ II Restrictions ]
3. Group operation of units in a system with multiple outdoor units
In the case of R2
CN41 CN40 L1
Replace
OC
51
TB7 TB3
M1M2
M1M2 S
Connect
In the case of R2
Leave the male
L21
connector
on CN41 as it is.
OC
52
TB7 TB3
M1M2
M1M2 S
NO
*1 BC and BS are found only in the R2 system.
Don'ts
1. M-NET remote controller and MA remote controller cannot
both be connected to the same group of indoor units.
2. No more than 2 MA remote controllers can be connected to
a group of indoor units.
3. Do not connect the terminal blocks (TB5) on the indoor units
that are connected to different outdoor units with each other.
4. Replacement of male power supply switch connector
(CN41) must be performed only on one of the outdoor units.
5. Provide grounding to S terminal on the terminal block for
transmission line for centralized control (TB7) on only one of
the outdoor units.
6. A transmission booster must be connected to a system to
which more than 26 indoor units including one or more in-
door units of 72 model or above are connected.
Sample control wiring
In the case of Y
L2 CN41 CN40
Replac e
OC
*1 BC
51
53
TB02 TB7
M1M2
M1M2 S M1M2 S
Connect
M1M2 S
TB02
55
*1 BS
In the case of Y
Leave the male
L22
connector on CN41 as it is.
OC
*1 BC
52
54
TB02 TB7
M1M2 S M1M2
M1M2 S
NO
L2 L3
Group Group
IC IC
01 05
TB3 TB5 TB15 TB5
M1M2 S 1 2 M1M2 S
A1 B2
MA
L22 L23
Group
IC IC
02 03
TB3 TB5 TB5 TB15
TB15
M1M2 S 1 2 M1M2 S
A1 B2
Maximum allowable length
(1) Indoor/outdoor transmission line
Maximum distance (1.25mm
(L1)* +L2+L3+L4 200m [656ft]
(L21)* +L22+L23+L24 200m [656ft]
*L1 and L21 are applicable only in the R2 system.
(2) Transmission line for centralized control
Maximum line distance via outdoor unit
2
(1.25mm [AWG16] or larger)
(L1)* +L2+L3+L4+L31
+(L21)* +L22+L23+L24 500m [1640ft]
*L1 and L21 are applicable only in the R2 system.
(3) MA remote controller wiring
Same as [4] 1.
- 30 -
Interlock operation with
the ventilation unit
L4
LC
06
TB15 TB5
1 2 M1M2 S
A1 B2
MA
NO
L24
IC
04
TB5 TB15
1 2 M1M2 S 1 2
MA
2
[AWG16] or larger)