SiEN34-705
Installation
General Information
73
2. Cable size
The thickness of the cables in the circuits (branch circuits) providing the main power supply to
each item of apparatus must satisfy the following conditions:
1. To have a current tolerance of 40% or more of the rated current of the overcurrent circuit
breaker (wiring circuit breaker, etc.).
2. To have a current tolerance of 125% or more of the rated current in cases where the rated
current of the apparatus is 50A or less.
3. To have a current tolerance of 110% or more of the rated current in cases where the rated
current of the apparatus is more than 50A.
4. To satisfy voltage drop standards.
3. Separation of control and power supply cables
!
If control and power cables are run alongside each other
then there is a strong likelihood
of operational faults developing due to interference in the signal wiring caused by
electrostatic and electromagnetic coupling.
The table below indicates our recommendations as to the appropriate spacing of control and
power cables
where these are to be run side by side.
Notes:
1. The figures are based on an assumed length of parallel cabling up to 100m. For lengths in
excess of 100m the figures will have to be recalculated in direct proportion to the additional
length of cable involved.
2. If the power supply waveform continues to exhibit some distortion the recommended
spacing in the table should be increased.
If the cables are laid inside conduits then the following points must also be taken into account
when grouping various cables together for introduction into the conduits.
1. Power cables (including power supply to the air conditioner) and signal cables must not be
laid inside the same conduit. (Power cables and signal cables must each have their own
individual conduits.)
2. In the same way, when grouping the cables, power and signal cables should not be bunched
together.
!
Important points
1. Earthing
!
Have the indoor and outdoor units both been earthed?
∗
If the apparatus is not properly earthed then there is always a risk of electric shocks. The
earthing of the apparatus must be carried out by a qualified person.
Current capacity of power cable
Spacing
100V or more
10A or less
300mm
50A
500mm
100A
1000mm
100A or more
1500mm
[Indoor unit]
[Outdoor unit]
Earth line
Earth line
