Hitachi RAS-10HRNM, Service Manual, Page: 274 / 482

Alarm code
51
Abnormal operation of the current sensor
• The RUN LED flickers and "ALARM" is displayed on the remote control switch.
• The unit number, the alarm code and the unit code are alternately displayed on the set temperature section.
The unit number and the alarm code are displayed on the display of the outdoor unit PCB.
– This alarm code is displayed when the current transformer is abnormal (0 A detection or 5 A alarm condition) and
the alarm has more than three occurrences in 30 minutes.
– Condition of Activation:
♦ When the frequency of the compressor is maintained at 15~18 Hz after the compressor is started, one of the
absolute values of the running current at each phase U+, U-, V+ and V- is less than 1.5 A (including 1.5A)
♦ Before the compressor is operated (at the end of position control), the current wave value is less than 5.0 A
Group A: RAS-(2-3)HVRN(1)(E)(S)
Group B: RAS-(3-6)HVRNM(S)E
RAS-(5-6)HRNM1E
RAS-(4-6)HVRNS1E
Group C: RAS-(8-12)HRNM
RAS-(8/10)HRNSE
Group D: RAS-4HRNMIE
Replace the ISPM (Group)
and ISPM
(Group D) if faulty
N O T E
• *1) P17 is shown at 7-segment on the outdoor unit PCB.
• *2) Perform the high voltage discharge work by referring to the item Procedure of checking other main parts
for ES Series , see on page 312 in part “Checking procedure for the electronic expansion valve” before checking
and replacing the inverter parts.
8 Troubleshooting
266
SMGB0060 rev. 1- 12/2010