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English
L-2091 Installation
On systems with two plates, the CPV is connected to the inlet
side of the fi rst plate, and a jumper line is attached between
the plates. The suction line then returns to the condensing unit.
See Figure 14. The lineset is in series:
Condensing Unit – CPV – Plate 1 – Jumper – Plate 2 – Condensing Unit
The quick connect fi ttings “polarize” the connections, so
the connections can not be confused as long as the CPV is
connected to the plate inlet. The system will be open once the
lines are attached.
The CPV is preset at the factory to 2 psi, and no further
adjustment should be needed. However, if using the system as
a refrigerator only, you can raise the low side pressure to 10-12
psi to increase effi ciency. See the table below:
SYSTEM CPV SET POINT DIFF.
Bait Box 2 psi 0°– 10°F/-18°– -12°C 5°F
(Freezer)
Catch Box 10-12 psi 35°– 40°F/1.7°– 4.4°C 5°F
(Refrigerator)
Note: set point range is meant as an example and does not
guarantee box temperature.
The CPV, and all connections after it back to the condensing
unit, should be well insulated to prevent condensation and ice
from forming on the lines. The plastic adjustment cap must be
installed on the CPV to prevent moisture entering the valve
and freezing. Refer to “Setting the CPV” in the Operation Sec-
tion, “Recharging the System.”
Thermostatic Expansion Valve (TXV)
Placement
Used in place of the CPV, the Thermostatic Expansion Valves
(TXV) must be installed in an accessible location and fastened
properly. Do not install TXV with the diaphragm on the bottom.
Recommended location of the TXV is near the box with the
plate. It may also be located in the box unless it is in a fi shbox.
The TXV sensing bulb is to be properly located and secured on
the outlet (suction line) of the last plate in series as close to the
plate as possible. Recommended location is on a horizontal
portion of tubing on the top (between eleven and one o’clock).
The full length of the bulb should be in good thermal contact
with the refrigerant tubing. Attach it to the closest straight
piece of tubing exiting the last plate. If either the expansion
valve or its sensing bulb is located outside of the box, each
part must be properly insulated to protect against condensa-
tion, as well as to allow accurate temperature sensing of the
bulb. The bulb must be secured to the pipe with a metal clamp
to ensure fi rm contact with the pipe and prevent movement.
Plastic ties are not acceptable. Refer to “Adjusting the TXV” in
the Operation Section, “Recharging the System.”
Dual Box Applications
Use TXVs if two boxes are used in conjunction with one
condenser unit.
Quick-Connect Fittings
All plates and lines have quick-connect fi ttings. Quick-connect
(QC) fi ttings allow for the connection and disconnection of
refrigerant lines with no loss of refrigerant. They also allow for
the unit to come factory charged with refrigerant. All connec-
tions are polarized so that misconnecting the lines, condensing
unit, or evaporator is impossible. If installed correctly, they will
not leak. The majority of problems with these have been leaks
due to not tightening the connections properly. Over-tightening
(especially the coupling to tube adapter on the old, two-piece
fi ttings) can damage the fi tting. Newer QCs are a one-piece
model and may be tightened securely at the union nut.
For the standard one-piece type, the following procedure
for connecting the fi ttings must be used:
1. Lubricate the gasket seal on the male threaded coupling
with refrigeration grade oil.
2. Thread the union nut of the female coupling onto the male
threaded coupling by rotating the union nut clockwise.
3. Start the connection by hand, and then tighten the female
thread connection with a 15/16" wrench while holding
the opposite coupling with a 7/8" wrench. This should be
tightened to 10-12 ft-lbs.
For the old two-piece type, the following procedure for connect-
ing the fi ttings must be used:
1. Lubricate the gasket seal on the male threaded coupling
with refrigeration grade oil.
2. Thread the union nut of the female coupling onto the male
threaded coupling by rotating the union nut clockwise.
Important: Do not allow the coupling body to rotate on the
tube adaptor during connection.
3. Start the connection by hand, and then tighten the female
thread connection with a 3/4" wrench while holding the
opposite coupling with a 5/8" wrench. This should be
tightened to 6-8 ft-lbs. Do not over-tighten the coupling on
the tube adaptor; doing so may destroy the seal.
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