EPR SETTINGS
The pressure settings are based on a normal
2 psig pressure drop in the suction line when
the EPR control is mounted in the machine
room.
Evap EPR Pressure Setting (psig)
Temp Refrigerant Application
(
O
F) R404A/R507 R22
–25 11 5
–22 13 7
–20 14 8
–15 18 12
6 37 27
9 41 30
12 44 33
15 47 36
18 51 39
21 55 42
25 60 47
30 68 53
NOTE: The final test for proper EPR setting must be
discharge air temperature or product temperature.
WINTER CONDENSING PRESSURE
CONTROLS
The customer may specify lower pressure set-
tings than those recommended; however,
refrigeration performance may be aff e c t e d .
Minimum receiver pressure is 140 psig. If the
condenser is mounted more than the 6 foot
minimum distance above the Flooding Valve,
add 1 psig to the Flooding Valve Setting for
every additional 2 feet of elevation.
Refrigerant Flooding Receiver
Valve Pressure
(Liquid) (Vapor)
(psig) (psig)
R22 175 165
R404A/R507 205 195
MECHANICAL LOW PRESSURE
CONTROLS
Alco
The Alco Low Pressure Control comes with a
factory set cut-in pressure of 15 psig. Since
the differential is fixed at 10 psig, the cut-out
is 5 psig, which is the lowest possible cut-out
for this control. A small right-angle Phillips
screwdriver is required to access the adjust-
ment screw—located next to the pressure con-
nection. Turn the screw clockwise (when fac-
ing screw head) to increase cut-in pressure.
N o t e : 3
1
⁄2 rotations of the screw represent the entire
70 pound adjustment range. Very roughly,
1
⁄2 turn equals
10 psig.
HUSSMANN CORPORATION • BRIDGETON, MO 63044-2483 • Printed in USA
CONTROL SETTINGS Revised August 1, 1996
8 - 2
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