Daikin VRV II Series, Design, Installation & Testing Instructions, Page: 59 / 242

Si39-303 Installation
General Information 53
d) In the case of a remote controller with a three way selector for cooling, heating and ventilation, twin core
cable should be used when the ventilation mode is not required and three core cable should be used
when three way selection is required.
e) Since there is a considerable risk of mixing high (220 to 240V) and low voltage in the case of, for
example, a PCB for remote control, multiple core cable must not be used.
(Internal wiring regulations and dielectric strengths of cables are relevant here.)
f) Other important points
1. The refrigerant circuit and the indoor/outdoor connecting cables must correspond exactly.
2. A suitable gap must be left between the control cables and the power supply cables where these are
laid alongside each other. (See “Separation of control and power supply cables” on page 54)
Power Supply
(Cabling of Main
Power Supply)
1. Choosing a circuit breaker
The power supply work must conform to local regulations. In Japan, the relevant regulations are the MITI
ordinance determining technical standards for electrical equipment, and the Internal Wining Provisions.
a) The indoor unit circuit breakers
!
In accordance with the provisions for internal wiring (JEAC8001-1986), power may be supplied by
means of crossover lines between the indoor units in a single system branch circuit.
When using high static pressure indoor units the fan motors must have a large capacity. Single phase
220~240V branch circuits are therefore required for each indoor unit.
Example: Up to 10 × 2.5HP indoor units or 5 × 5HP indoor units can be wired together.
b) The outdoor unit circuit breaker
!
A separate circuit breaker must be fitted for each unit.
!
The motors incorporated into air conditioning system compressors are treated as special motors under
the internal wiring provisions. The values which apply to normal motors are thus somewhat variance
with those which apply to such compressor motors. You are recommended to adhere strictly to the
procedures laid down in the technical materials included in, for example, the system design manuals.
Calculation of load (Refer to local regulation.)
With respect to the calculation of load for motors with special applications such as elevator, air conditioner
and refrigerator motors, not only must the rated current be shown on the name plate of the said motor or
piece of apparatus but it must also included all special characteristics or applications.
Branch circuit facility (Internal wiring provisions
305-2)
The motors must be set up with a dedicated branch
circuit for each unit. However, where they
correspond to any of the following situations, this
limitation does not apply.
When used in a 15A branch circuit of a 20A
circuit breaker branch circuit
Note: It is recommended that the total rated
capacity of the motors set up in a 15A branch circuit
or a 20A circuit breaker branch circuit should be no
more than 2.2kW.