Types And Maximum Allowable Length Of Cables - Mitsubishi Electric CMB-WM108V-AA Service Handbook

[ II Restrictions ]

[2] Types and Maximum Allowable Length of Cables

1. Wiring work
(1) Notes
1) Have all electrical work performed by an authorized electrician according to the local regulations and instructions in this man-
ual.
2) Install external transmission cables at least 5cm [1-31/32"] away from the power supply cable to avoid noise interference.
(Do not put the control cable and power supply cable in the same conduit tube.)
3) Provide grounding for the outdoor unit as required.
4) Run the cable from the electric box of the indoor or outdoor unit in such way that the box is accessible for servicing.
5) Do not connect power supply wiring to the terminal block for transmission line. Doing so will damage the electronic compo-
nents on the terminal block.
6) Use 2-core shielded cables as transmission cables.
Do not use a single multiple-core cable to connect indoor units that belong to different refrigerant systems. Doing so may result
in signal transmission errors and malfunctions.
Outdoor unit
TB TB
3 7
2-core shielded cable
TB TB
3 7
2-core shielded cable
TB3: Terminal block for indoor-outdoor transmission line TB7: Terminal block for centralized control
7) When extending the transmission cable, be sure to extend the shield wire.
(2) Control wiring
Different types of control wiring are used for different systems. Before performing wiring work, refer to the following page(s).
[7] Example System with an MA Remote Controller
[8] Example System with an ME Remote Controller
[9] Example System with an MA and an ME Remote Controller

Types and maximum allowable length of cables

Control lines are categorized into 2 types: transmission line and remote controller line.
Use the appropriate type of cables and observe the maximum allowable length specified for a given system. If a given system
has a long transmission line or if a noise source is located near the unit, place the unit away from the noise source to reduce
noise interference.
1) M-NET transmission line
Cable type
Maximum transmission line dis-
tance between the outdoor unit and
the farthest indoor unit
Maximum transmission line dis-
tance for centralized control and In-
door/outdoor transmission line
(Maximum line distance via outdoor
unit)
HWE1708A
HBC Controller Indoor unit
Remote Controller
Facility type
Type
Number of
cores
Cable size
1000 m [3280ft] (500 m [1640ft]) max.
*The maximum overall line length from the power supply unit on the transmission
lines for centralized control to each outdoor unit or to the system controller is 200m
[656ft] max.
*1 If a given system includes one or more unit or remote controller that does not
support the maximum allowable cable distance of 1000 m [3280 ft], the maxi-
mum allowable cable distance in the system will be 500 m [1640 ft]. Refer to the
latest catalog for information on which units and remote controllers support the
maximum allowable cable distance of 1000 m [3280 ft].
Outdoor unit
TB TB
3 7
multiple-core cable
TB TB
3 7
All facility types
Shielded cable CVVS, CPEVS, MVVS
2-core cable
2
Larger than 1.25mm [AWG16], or ø1.2mm or above
200 m [656ft] max.
*1
- 30 -
HBC Controller Indoor unit
Remote Controller
GB