Hitachi RAS-50WX8 Service Manual page 161

HOW TO OPERATE USING THE SERVICE SWITCH THE OUTDOOR UNIT
MODEL RAC-50WX8, RAC-D18EX3
1.Turn the power switch off and then turn on again.
2.Remove the electrical parts cover.
LD303 (red) will light and the unit will operate in the forced cooling mode at this time.
Never operate the unit
in this state for more
than 5 minutes.
(Cautions)
(1) If interface signal (35V DC) terminals C and D are not connected when the outdoor unit service switch is used
for checking, the outdoor unit defect indicator (LD301) will blink 9 times after operation to indicate
communication error.
(2) If checking is done with the compressor connector disconnected, the unit will continue normal operation when
the electrical parts are normal, or it will repeat operating for approx. one minute and stop due to overload
power limit cut, or it will operate in the overload status.
Be sure to return the service switch to "normal" after checking with service operation is completed.
HOW TO OPERATE THE OUTDOOR UNIT INDEPENDENTLY
1. Connect the large dia. pipe side and small dia. pipe side service valves using a pipe.
Connect the small diameter
service value and the large
diameter service valve using the
reducing union and copper pipe
as shown on the right.
Charge refrigerant of 300g
after vacuuming ( ※1)
The operation method is the same as "How to operate using the connector to servicing the outdoor unit".
※1 The charging amount of 300g is equivalent to the load in normal operation.
Open the upper cover
Electrical parts cover
Outdoor unit
Compressor
Reversing
valve
Large dia.service valve
Reducing union
(2/8" and 1/2")
Copper pipe
(2/8")
Small diameter
service valve
– 202 –
Service switch
(forced-cooling mode is set by
pressing for 1 second or
more, and stopped by pressing
again.)
Parts to be prepared
Reducing union
(1)
2/8" (6.35mm)
1/2" (12.7mm)
Copper pipe (2/8" and 1/2")
(2)
Shorting leads
(3)
2 leads approx. 10 cm long
with alligator clip or IC clip
Do not operate for 5 minutes
or more.