KOOLGAS DEFROST CYCLE
Beginning with the
Receiver
the Koolgas Cycle
splits in two directions—Receiver Vapor and
Receiver Liquid. The high pressure liquid flowing
from the Receiver is throttled by the
Main Liquid
Line Solenoid Valve
causing a pressure reduction
in the
Liquid Manifold
.
The
Branch Liquid Line Solenoid Valve
is
designed to allow backflow into the reduced pres-
sure Liquid Manifold. When a branch of refrigera-
tion cases enters the defrost cycle its
Branch Valve
allows refrigerant to flow into the Liquid Manifold.
The valve solenoid is energized both for refrigera-
tion and for defrost.
The Receiver Vapor flows directly into the
Koolgas Manifold
. This Koolgas Vapor maintains
the same high pressure as the Receiver. A
3-Way Valve
closes the suction line to the
Suction Manifold
and opens the Koolgas line to
the
Evaporator.
Koolgas Vapor flows backward
through the Evaporator, giving up heat to the
Evaporator for defrost.
The Koolgas Vapor condenses and flows into the
reduced pressure liquid line through a
Bypass
Check Valve
around the TEV. From there it is
returned to the
Liquid Line Manifold.
If a
Suction Stop EPR Valve
is used to control
Evaporator temperature, the 3-Way Valve is not
used. When defrost is called for, the suction line
control valve closes and a two-way
Koolgas
Valve
opens the line from the Koolgas Manifold
to the Evaporator.
September 1, 1997
P/N 401789
2 - 7
HUSSM ANN CORPORATION • BRIDGETON, M O 63044-2483 • Printed in USA
KS
Evaporator
EPR
Suction Manifold
Koolgas Manifold
Evaporator
MS
S_
3W
Liquid Manifold
Suction Manifold
Koolgas Manifold
KS
SS
Defrost Mode
Refrigeration Mode
Evaporator
High Pressure Hot Vapor
High Pressure Warm Liquid
High Pressure Warm Vapor
Low Pressure Cool Vapor
Reduced Pressure Warm Liquid
Receiver
Figure 2-13 — Koolgas Defrost Cycle
Figure 2-14 — Koolgas Defrost with Valve
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