BRANCH LIQUID LINE
SOLENOID VALVES
The Branch Liquid Line Solenoid Valve closes off
refrigerant supply to the evaporator, yet allows
back flow of refrigerant into the Liquid Manifold
for Koolgas Defrost.
When the Solenoid is de-energized the Valve Port
➀
is held closed. Higher Pressure
➄
upstream
fills the Valve Chamber
➂
through the Equalizing
Port
➃
, keeping the Valve closed.
In refrigeration the Valve Port
➀
opens, emptying
Valve Chamber
➂
through the Check Valve
➁
faster than the Equalizing Port
➃
can fill it.
Higher Pressure
➄
upstream forces the Valve
open.
During Defrost, Valve Port
➀
opens, removing
kick spring force from the valve. Higher Pressure
➄
downstream back flows, closing the Check
Valve
➁
and forcing the Valve up. Equalizing Port
➃
allows Valve Chamber
➂
pressure to escape
upstream.
Note:
The Solenoid of the branch valve is ener-
gized during refrigeration and for back flow
during defrost.
Table 6-3 — Troubleshooting
Branch Liquid Line Solenoid Valves
CONTROL VALVES
September 1, 1997
6 - 6
HUSSM ANN CORPORATION • BRIDGETON, M O 63044-2483 • Printed in USA
Malfunction
Cause
Action
Fails to Open
Dirt plugging valve port
Disassemble and clean
or equalizing port
Solenoid not energized
-bad solenoid
Replace solenoid
-circuit open
Find and repair open
Fails to close
Dirt in valve port
Clean or replace
or equalizing port
Barrel or piston scored
Replace
Dirt in piston chamber, causing drag
Clean or replace
Valve Detail
Check Valve
Valve Port
Upstream
Equalizing Port
Refrigeration - Forward Flow
5
Energized
4
2
1
3
Defrost - Back Flow
5
1
Energized
2
3
4
Branch Liquid Line Solenoid Valve
5
De-energized
4
2
1
3
Figure 6-7 — Branch Liquid Line
with Back Flow
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