Haier AW07LC2VHA Technical Overview page 15

Power Circuit Board (PCB)
The purpose of the Power Circuit Board is to filter out poten-
tial electrical noise before it reaches the outdoor unit elec-
tronic circuits. All voltage to operate the outdoor unit circuits
must pass through the PCB.
1
A replaceable 25A 250V rated ceramic fuse protects
the outdoor unit electronics. The fuse would open if a power
surge or internal short in the outdoor unit occurred. This fuse
is field replaceable.
2
The Power Circuit Board (PCB) receives line voltage
from the building power supply via a connection between the
Line Power terminal on the outdoor unit and the terminals P1
and P2 of the PCB.
6 6
5
OUTDOOR UNIT TECHNICAL OVERVIEW Technical Overview
Power Circuit Board (PCB)
Ground
3
TECHNICAL OVERVIEW
3 4 5
The voltage that powers the indoor units
connects to terminals P3 and P4. The Electronic Control Unit
receives power to operate via connections at terminals P5
and P6. The Compressor Module board receives power via
connections at terminals P7 and TERMINAL 3.
When power is available to the Electronic Control Board and
the Compressor Module board, their respective GREEN LED
indicators will be flashing if the unit is in standby, or continu-
ously lit if the system is running. If the GREEN LED is not lit,
there may not be power to either the PCB or the board receiv-
ing power from the PCB. (The Power Control Board does not
have a power indicating LED.)
6
There is a communication plug labeled CN-1 on the
PCB. This plug connects from the PCB to the Electronic
Control Unit (ECU). If this cable is disconnected or loose, the
system will generate a Code 6 module low or high voltage
error. This error will not be displayed in memory on the indoor
unit wired controller.
4
2
1
25A 250V
Fuse
PAGE 15