Carrier 5F - Manual (Page 15)

HEATING A COOLING
5F,H
Open-Drive Compressors
CONTACT ARM RESISTANCE
CONNECT IN
SERIES WITH
CONTROL CIRCUIT
T
240
VAC
±
VAC
REFER TO UNIT LABEL
WIRING DIAGRAM)
HIGH-PRESSURE
CONNECTION TO
OIL PUMP
DISCHARGE
LOW-PRESSURE
CONNECTION
TO CRANKCASE
Fig. 14 — Oil Pressure Safety Switch
SPRING DETAILS
7-LB SPRING
R-12 USAGE
11-LB SPRING
R-22, R-502
USAGE
m
*When compressor Is received, the capacity control adjusting
stem will be backseated. (Compressor will be fully loaded under
all conditions )
Fig. 15 — Capacity Control Valve
An external adjusting stem (Fig. 15) sets the control
point (suction pressure at which first step of cylinder
unloading occurs). The control point is adjustable
as follows:
R-22 and R-502 .............................................. 0 to 85psig
R-12................................................................. 0to50psig
One full clockwise turn of adjusting stem will raise the
control point approximately 6psig with R-12, or lOpsig
with R-22 and R-502.
Control oil pressure is an indication of cylinder loading
condition (Table 6). Refer to Fig. 3-8 for location of
control oil-pressure gage connection. See Accessory
Unloader Paekage Installation Instructions for addi­
tional information.
Table 6 — Control Oil Pressures for
Cylinder Loading and Unloading
COMPRESSOR STEP*
APPROXIMATE
CONTROL OIL PRESS. (psIg)
Loading Unloading
5F20 1 19 8 13.0
5F30
1
2
30 0
198
20 2
130
5F40,60; 1 30.0 19.0
5H40,46, 2 26.0 160
60,66,80, 3 23 0 120
86,120,126 4 20 0 9.0
‘Capacity control reduction steps
To Adjust Control Point
1. Impose an artificial load on the compressor until
suction pressure exceeds control point.
2. Slowly close suction valve to lower compressor
suction pressure to eontrol point pressure.
3. When at control point pressure, turn external
adjusting stem clockwise until first step of unloading
takes place, as indicated by ehanges in control
oil pressure, current draw and sound of compressor.
Control point is now set. Reopen suction service valve.
Compressor will be fully loaded when suction pressure is
3psig (4psig with R-22 and R-502) above control point,
and will be fully unloaded when suction pressure is 4psig
(7 psig with R-22 and R-502) below control point.
5F20 AND 5F30 COMPRESSORS — Two capacity
control packages are available as accessories. One is
suitable for R-12 applications; the other for R-22 and
R-502 applications.
The adjusting stem (Fig. 15) is shipped in a backseated
(fully eounterclockwise) position. Compressor will be
fully loaded under all conditions. Adjust the capacity
control set point by the same 3-step procedure described
above for 5F40 through 5H126 compressors.
Manufacturer reserves the right to discontinue, or change at any time, specifications or designs without notice and without incurring obligations.
Bookl 2 PC111 Catalog No 530-526 PrintedinUSA Form 5F,H-11SI Pg15 2-86 Replaces: 5F.H-9SI
Tab I 2a For replacement items use Carrier Specified Parts