Wiring 7.1 Power Supply Equipment; Miv And Wivm Wiring - Hitachi NEXT Series Instruction Manual

7. WIRING
1. Always use a licensed electrician. Do not allow an unlicensed person to wire the compressor. An
unlicensed person may wire the air compressor wrongly, and a wrong wiring may cause an electric shock.
2. Do not remove any protective relays on the air compressor. Also, do not make a modification of the
control circuit that may result in impairing the protective relay's function. Remember that the loss of the
protective relay's function may cause serious damage to the air compressor such as a burning of the air
end. In the event that you need to modify the control circuit, consult your distributor.
3. Before opening the control panel to service or wire the air compressor, disconnect the power; otherwise
you may receive an electric shock. Even when the power is disconnected, the controller (V-type only)
and the fan inverter (air-cooled type only) are still charged. Be sure to wait approximately 10 minutes
after power-off and check that the charge lamp of the controller or the fan inverter is completely off
before starting the procedure. In addition, attach a notice on the power supply stating "Under the
maintenance work. Keep the switch off." to prevent someone from carelessly turning the switch on.
7.1 Power Supply Equipment
Use a power supply transformer with adequate kVA
capacity and a power cable with adequate thickness and
length. If properly sized transformers and cables are not
used, excessive voltage drop could occur when the
START button is pressed, it results in 1.) Motors failing
to fully accelerate and/or, 2.) An inefficiently energized
control circuit; thus shutting down the air compressor.
To keep a starting voltage drop within an allowable range
(5% of the rated voltage), use the power supply transformer
Item/Voltage
Power transformer capacity
(kVA)
Power cable thickness AWG
(mm )
2
Capacity values are reference data; some power supplies may require a larger-capacity transformer.

7.2 MIV and WIVM wiring

WIRING FOR MIV
WIRING No. 'DA'
1
WIRING No. '44'
2
3
WIRING No. '43'
4
CABLE FROM TB3 IN THE CONTROL PANEL
5
TERMINAL BOX OF MIV
WIRING FOR WIVM
WIRING No. 'DA'
BLACK
WIRING No. '46'
WHITE
WIRING No. '45'
RED
GREEN
CABLE FROM TB3 IN THE CONTROL PANEL
YELLOW
TERMINAL BOX OF WIVM
WARNING
Model 45/55ATN
45/55WTN
460 V 100 or more
1 to 3/0
460 V
(60 to 100)
and power cable in the table shown below. Lower
thickness values are based on the power cable length of
less than 394 inch (10 m). In the event that the power
cable is longer than 394 inch (10 m), employ a thicker
power cable. Provide intermediate terminals to keep the
power cable thickness lower than the maximum values at
the air compressor terminal block. The maximum
voltage imbalance between the phases shall be within
1%.
75ATN 55VATN
75WTN 55VWTN
150 or more 100 or more
2/0 to 300 1 to 3/0
(80 to 150) (60 to 100)
① Electrical wiring of Motorized Isolation Valve (MIV),
and Motarized Water Isolation Valve (WIVM) shall be
install on side. Refer to the drawing.
(WIVM is only for water-cooled.)
75VATN
75VWTN
150 or more
2/0 to 300
(80 to 150)
53