Discharge Procedure And How To Cut Off Power To Power Circuit - Hitachi RAM-90QH5 Service Manual

Discharge procedure and how to cut off power to power circuit

Caution
DANGER
Voltage of about 360V is charged at both ends of smoothing capacitor 330 µ F x 6.
G
High voltage (DC 360V) is also charged at terminal sections of ACT module and power module.
G
During continuity check of each circuit of electrical parts in outdoor unit is performed, to prevent
G
secondary trouble, disconnect red/gray wire connected to ACT module from diode stack. (Also be sure to
perform discharging of smoothing capacitor.)
1. Disconnect power plug.
2. Wait for 10 minutes or more after power is turned off and then remove electrical parts box lid. As shown below.
Apply soldering iron of 30-75W for 15 seconds or more to P1 and N1 black/white lead receptacles on Capa
board to discharge voltage from smoothing capacitor.
Do not loosen or remove screws of system power module: If screw is loose, voltage will not be discharged.
3. Before operation check of each part of circuit, remove receptacle of red/gray lead connected to ACT module
from diodde stack.
BLK
LEAD
WIRE
WRT
CAPACITOR BOARD
Sondering iron
– 89 –
Do not use soldering iron with
transformer: Doing so will blow thermal
fuse inside transformer.
As shown left, apply soldering iron to metal
parts TAB 01 P and TAB 02 terminals of
Capa board.
Terminals of ACT module