Hitachi EV-1.5N1, Service Manual

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8. Troubleshooting
283
SMGB0079 rev.0 - 01/2013
8
8.4.2 Checking capacitors CB1 & CB2.
D A N G E R :
• Electrical hazard. Risk of serious injuries or death.
• Before installing the electrical wiring or before performing a periodical check, turn OFF the main switch of the
unit. For safety reasons, be sure that the fan is stopped.
• Prevent from touching the capacitors’ terminals. High voltage should be present before discharging them.
• Turn off the unit and wait for the LED 201 to be off before touching the components.
If it’s possible, check the capacitance of each capacitor : 4700μF ± 20% (between 3760μF to 5640μF).
A visual check of the pressure valve of capacitors
must be done to ensure it’s integrity
N O T E
It is not recommended to check tension.
PN = Power source x √2, PC=CN is nearly equal to PN/2.
R1 & R2:
1 If the value is different:
- Capacitor could be damaged by overload.
- 04 alarm could be displayed if low supply voltage (CN) for ISPM control part is present.
2
R1 = 9.5Ω & R2 = 14.0Ω. If these values are different, the capacitors will be not properly charged.
Resistance between P1 & TB3 = 2kΩ (white resistance in the ISPM).
In case that Mg. SW 52C (CMC1) is not ON, the compressor current will travel through these resistances, and they will
be broken. Mg. SW 52C (CMC1) should be checked. Check the resistance between the primary and secondary terminal
where the contact point is melted for Mg. SW 42C. If there is continuity, the contact is melted and 52C is broken (NG).
Reactor resistance can be messured between TB3 and RB = 0,2Ω. Checking this component is not necessary.
N O T E
• Noise filter does not affect ISPM directly, so is not necessary to check it when ISPM fails.
• Both digital or analog testers are valid to check the values.