Electrical Wiring; Main Power Wiring Procedures; Control Wiring - Hitachi RUA-13AT3S Instruction Manual

ELECTRICAL WIRING

3. ELECTRICAL WIRING
Tools and Instruments – One set of wiring tools,
electrical tester (Clamp meter).
Schedule Check – Confirm that the field selected
electrical components (main power switch, fuses,
wires, conduit connections, wire terminals) are
properly selected and ensure that they comply
with national and local codes. It is recommended
that the main power switch be locked at the OFF
position, to prevent against accidental supply of
the power during unit servicing.
Service Panel – Access to the magnetic switch
box is provided from the service panel, which is
fixed with screws (see the panel location in the
Operation Instructions.)

3.1 Main Power Wiring Procedures

Confirm that electrical power is not being supplied
to the installation location prior to any electrical
installation work.
1. Install the field-supplied main switch box at the
properly selected location.
2. Install conduit connectors in the hole for power
wiring (knockout holes).
3. Lead the main power wires and the earthing
wire through the connector to the screw
terminals for main power and earthing in the
magnetic switch box. The neutral wire to 220V
power supplies should also be led through the
connector. Firmly connect the wires with wire
terminals to the unit screw terminals R(L1),
S(L2) and T(L3) for 220V power supplies
according to Fig. 6 or the wiring label attached
to the magnetic switch box.
A scroll compressor is equipped. Because that
the rotation direction of the orbiting scroll of the
HITACHI scroll
therefore a reverse & single phase sequence
protection relay is equipped in this unit. If each
phase R, S or T of the power source is incorrectly
connected, the compressor does not start due to
the activation of the reverse & single phase
sequence protection relay. Therefore, in order to
check the correct wiring connection, the utilization
of a phase sequence indicator is recommended
when the unit is started after installation of the
unit.
4
type compressor is
(1) If the phase is wrong, exchange two of the
three wires connected from the main power
source to the main terminals of the unit as
indicated with dotted lines, and then check the
rotation direction of the phase sequence
indicator once again. Do not exchange the
wires in the unit in order to protect the
compressor against the reversal rotation.
(2) Do not operate the compressor by depressing
the button of the magnetic switch for the
compressor.
A three-phase condenser fan motor is equipped;
therefore, the fan motor rotation should be
checked. Interchange two of the three main power
source wires, if incorrect rotation is detected
during initial start-up.

3.2 Control Wiring

Install the optional room thermostat at a suitable
location in the space to be air-conditioned.
Connect the control wires between the unit
terminals and the thermostat terminals according
to Fig. 6 or the wiring label.
fixed,
Main
Power
Wiring
Main
Power
Switch
(Field Supplied)
Unit Side
R S T
Earth Terminal
Main Power
Control
Terminal
Circuit
SL
Terminal
R S T
A B D
L1 L3
L2
Fig. 6. Field Wiring Connection
Fig. 6. Field Wiring Connection
Room Thermostat
(Field Supplied)
Unit
E F
Five (5) Wires for
Cooling Operation
(Utilize Connectors
A,B,D,E and F)