T-CU11-OCT22-0
Page 17
Installation
Electrical
The mains 3phase electrical supply to the condensing unit MUST fitted via a suitable
motor rated circuit breaker or fuse, to provide short circuit protection to the
condensing unit. A mains isolator MUST also be fitted to all condensing units unless site
conditions or regulations dictate differently.
Daikin condensing units require a 400 Volt / 3 Phase / 50Hz supply, both of which must include a Neutral and an Earth.
These systems are not suitable for any other supply voltages (other than specified in
and are not suitable for
60Hz supplies).
Table below is just a guideline for power supply cable sizes to the condensing unit for maximum length up to 30m.
Installer might specify cable size different from this guideline, depending on the wire material and length, system
design, ambient temperature, etc.
Table 9: Power Supply Wiring Sizes
Model
Cable size, mm
2
(from network to unit)
Maximum Fuse Rating (A)
LRMYS0180AXY1
2.5
15
LRMYS0250AXY1
2.5
15
LRMSS0400FXY1
4.0
20
LRMSS0500FXY1
4.0
20
LRMSS0600FXY1
4.0
25
Cables to the condensing unit should wherever possible be routed through the designated access (wire bush/valve
cover) on the rear-right panel and the termination at control panel should be stress relieved by tie the incoming supply
cable with the provided push releasable tie.
Ensure an adequate liquid charge has been introduced to the high side of the system
before starting to ensure a minimum operating pressure on the suction side of 0.5 bar
is maintained, otherwise overheating of the scroll and rotary and subsequent damage
may occur. Refrigerant blend must be charged in liquid form to avoid change of
chemical properties.
Never start the compressor under vacuum (do not operate the compressor with the
low-pressure cut-out bypassing), as
this will cause the rotating part to overheat very
quickly causing premature failure.
Do not use a megohmmeter nor apply power to the compressor while the system
under vacuum as this may cause internal damage to the compressor.