Advantage Maximum MG Series - Unit will Not Start; Compressor Hums but will Not Start; Shuts off on High Pressure

Maximum Series Portable Chiller : Air & Water-Cooled : MG Series Instrument
update 08/02/2021
Page: 46
ADVANTAGE ENGINEERING, INC.
525 East Stop 18 Road Greenwood, Indiana 46142
317-887-0729 Fax: 317-881-1277
Service Department Fax: 317-885-8683
Email: service@AdvantageEngineering.com
4.1 UNIT WILL NOT START
A. Power off. Check main disconnect.
B. Main line open. Check fuses.
C. Loose terminals. Tighten terminals with POWER OFF.
D. Control circuit open. Check control voltage fuses and transformer.
4.2 COMPRESSOR HUMS BUT WILL NOT START
A. Contactor problem. Check contacts and contactor operation.
B. Low voltage. Check voltage at main and at the unit. If voltage is OK at the main but low
at the unit, increase wire size. If low at main, consult your local power company. Voltage
must be +/- 10% nameplate rating.
C. No power on one phase of a three phase unit. Check fuses in control panel and main
disconnect. Also check unit wiring, main plant fuse and wiring. If the problem is with the
main power supply coming into the plant, call the local power company.
D. Loose terminals. Power off and follow all company lock-out tag-out procedure before
tightening terminals.
4.3 SHUTS OFF ON HIGH PRESSURE LIMIT
A. Air-cooled units:
1. Insufcient condenser air ow.Checkcondenserlterfordirt,nsmaybe
plugged with dirt or foreign material. Also, check for proper fan rotation.
Note: All enclosure panels must be attached.
2. Fan motor not operating. Have electrician check fuses and wiring, motor starter
and overloads, and motor. Repair or replace motor if defective.
B. Water-cooled units:
1. Water regulator valve. Adjust condenser water regulator valve to maintain
100°F to 105°F refrigerant condensing temperature*. If valve is defective, have
valve repaired or replaced by a refrigeration serviceman.
2. Thewaterregulatorvalveisnormallyfactorysetforproperoperation.Wheneld
adjustments are required, turn the adjusting nut on the top of the valve counter
WARNING: Before troubleshooting or servicing this unit, follow all company lock-out tag-out
procedures.
* See Temperature-Pressure
chart in Section 8.2 for
refrigerant pressure.