2.11 Reverse Rotation Protection
Correct compressor rotation is critical for com-
pressor reliability. The compressor can fail with-
in 2-6 seconds of start-up if it is not rotating in
the correct direction. Installation of a pressure
gage at the discharge pressure access fitting in
the compressor body (measuring the pressure
upstream of the integral discharge check valve)
is recommended during initial start-up or
whenever the compressor is serviced. The
gage should be monitored to ensure increasing
discharge pressure at start-up.
The new LonCEM protection module (available
midyear 2000) uses a pressure sensor to moni-
tor the discharge pressure change at start-up
to ensure proper compressor rotation. The
LonCEM module eliminates the need for a
mechanical low-pressure switch and line/load
phase monitor. See Appendix A for descrip-
tions of operation applications for the LonCEM
module.
2.12 Mufflers
Screw compressors emit very high frequency
gas pulsations that have the potential to result
in significant discharge line and oil separator
noise. The addition of the Carlyle screw com-
pressor muffler is required in all applications to
reduce discharge line and oil separator noise
levels
(Carlyle P/N LM10HH162)
. The muffler
should be located within 6-in. of the compres-
sor discharge service valve.
10
L3
L2
L1
LS3
LS2
LS1
LOW VOLTAGE
HIGH VOLTAGE
LOAD ENERGIZER
FAULT
INTERROGATION
SECONDS
SYMMETRY
LOCKOUT
MINUTES
L3
L2
L1
FUSE
FUSE
FUSE
C
LS1
LS2
LS3
LOAD
CONTROL
VOLTAGE
19-240
VAC/VDC
CHECKS
LOAD
VOLTAGE
CHECKS
SOURCE
VOLTAGE
PHASE MONITOR WIRING DIAGRAM
CONTACTOR
VOLTAGE
ADJUST
FOR REFERENCE ONLY
INCHES
[MILLIMETERS (mm)]
Screw Compressor Muffler
PHASE MONITOR WIRING DIAGRAM