LG Therma V HM091MRS Installation Manual page 87

How to Install 3way Valve for Backup Heater Bypass
Follow below procedures Step 1 ~ Step 2.
Step 1. Uncover front cover of the unit.
Step 2. Find terminal block and connect wire as below.
When Tightening the connect wire on terminal block, Be careful to prevent a shock or injury.
(230 VAC)
2WAY VALVE
(B)
18 19 20
BR WH BL
L L1 N
(NO) (NC) (N)
3way valve
How to Connect Backup Heater Sensor to Unit
Follow below procedures Step 1 – Step 5.
① Find backup heater terminal block Kit(Fig. 1).
② Assemble the terminal block kit using screw on unit.(referring to 40 page)
③ Plug it to 'E/Heater Out' (White Connector) of CN_TH3 in the Main PCB (Unit) as shown Fig.2.
④ Connect harness between the unit and the Backup Heater until it clicks into place.(Fig. 3).
⑤ Use the cord clamper to fix the cable through low voltage hole.
Fig.1
h The terminal block connection number may differ depending on the model. Refer to the
"Wiring Diagram" in the SVC Manual.
WARNING
!
• When type of 2way valve is NO type, 3way valve should
select Flow A(bypass). Electric power is supplied to wire(NO)
and wire(N).
• When type of 2way valve is NC type, 3way valve should
select Flow B(heating In Backup heater). Electric power is
supplied to wire(NC) and wire(N).
CAUTION
!
• 3way valve should be connected together with 2way valve in
terminal block.
• Keep the distance between 3way valve and Backup Heater
more than 0.5m.
• To prevent reverse flow, It is important to use one way
valve(check valve) to Backup Heater water outlet.
E/HEATER OUT
SENSOR
(5 V DC)
7
31 32
A B
E/HEATER OUT
SENSOR
(5 V DC)
Fig.2
ACCESSORIES INSTALLATION
Fig.3
87