Simple Check On Inverter Circuit Components - Mitsubishi Electric PUHY-HP72 Service Handbook

[8-9 Troubleshooting Inverter Problems ]
8-9-13

Simple Check on Inverter Circuit Components

Turn off the power to the unit, and leave it turned off for at least 10 minutes. Check that the voltage across pins 1 (+) and
5 (-) of the connector RYPN1 is 20 VDC or less before removing components from the control box.
Part name
IGBT module Refer to the following page(s). [8-9-14 Troubleshooting Problems with IGBT Module]
Rush current pro- Measure the resistance between terminals R1 and R5: 22 ±10%
tection resistor
R1, R5
Electromagnetic
relay
72C
YNU
TNU
DC reactor Measure the resistance between terminals: 1 or lower (almost 0 )
DCL Measure the resistance between terminals and the chassis:
Current sensor Disconnect the wiring connector from CNCT2, and measure the inter-teminal resistance: 280 ±30
ACCT Between pins 1 and 2 (U-phase), pins 3 and 4 (W-phase)
HWE18240_GB
This electromagnetic relay is rated at DC12V and is driven by a coil.
Check the resistance between terminals
4 3
1 2
4 3
1 2
ACCT-U
*Check ACCT wiring for correct phase and direction.
Judgment method
Check point
INV board
X901, X902
Coil
Across pins 1-2
INV board
FT-P1 and FT-P2
Contact
*Faston terminal removed
At a voltage input of 12 VDC: 0Ω
Check point
INV board
X901, X902, X903
Coil
Across pins 1-2
INV board
FT-P1 and FT-P2
Contact
*Faston terminal removed
At a voltage input of 12 VDC: 0Ω
INV board
SC-U SC-V SC-W
U W ACCT-W
Checking criteria
160Ω ± 10%
INV board CNRY
Open: ∞
INV board CNRY
Checking criteria
160Ω ± 10%
INV board CNRY
Open: ∞
INV board CNRY
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