Frick SGC 1913 - Page 27

070.650-IOM (AUG 2015)
Page 27
SGC ROTARY SCREW COMPRESSOR
MAINTENANCE
TROUBLESHOOTING THE SGC COMPRESSOR
SYMPTOM PROBABLE CAUSES and CORRECTIONS
SLIDE VALVE and/or SLIDE STOP
WILL NOT MOVE
• 4-way hydraulic control valve failed. Repair or replace.
• Slide stop indicator rod stuck. Contact
Johnson Controls – Frick Service for assistance.
• Check both S.V. and S.S. feedback devices for wiring and resistance.
•Compressormustberunningwithsufcientoilpressure.
• Unloader piston stuck. Contact J
ohnson Controls – Frick Service for assistance.
• P
iston Seals worn out/damaged. Contact Johnson Controls - Frick Service for assistance.
NOTICE
Unless the Service Technician has been certied by Johnson Controls – Frick to rebuild our compressors,
troubleshooting the compressor is limited to identifying the probable cause. If a mechanical problem is suspected
contact Johnson Controls – Frick Service. DO NOT ATTEMPT TO DISASSEMBLE COMPRESSOR.
TROUBLESHOOTING THE HYDRAULIC SYSTEM
SYMPTOM PROBABLE CAUSES and CORRECTIONS
SLIDE VALVE WILL NOT LOAD OR
UNLOAD
• Solenoid coils burned out. Replace.
• Valve closed. Open hydraulic service valves.
• Solenoid spool stuck or centering spring broken. Replace.
• Check LED on coil. If lit, there is power to the coil. Check coil.
• Solenoid may be actuated mechanically by inserting a piece of 3/16” rod against
armaturepinandpushingspooltooppositeend.PushAsidetoconrmunload
capability. If valve works, problem is electrical.
SLIDE VALVE WILL LOAD BUT
WILL NOT UNLOAD
• A side solenoid coil may be burned out. Replace.
• Dirt inside solenoid valve preventing valve from operating both ways. Clean.
• Check LED on coil. If lit, valve is functioning mechanically. Problem is electrical.
• Solenoid may be actuated mechanically by inserting a piece of 3/16” rod against
armaturepinandpushingspooltooppositeend.PushAsidetoconrmunload
capability. If valve works, problem is electrical.
SLIDE VALVE WILL UNLOAD BUT
WILL NOT LOAD
• A side solenoid coil may be burned out. Replace.
• Dirt inside solenoid valve preventing valve from operating both ways. Clean.
• Check LED on coil. If lit, valve is functioning mechanically. Problem is electrical.
• Solenoid may be actuated mechanically by inserting a piece of 3/16” rod against
armaturepinandpushingspooltooppositeend.PushAsidetoconrmunload
capability. If valve works, problem is electrical.
SLIDE STOP WILL NOT FUNCTION
EITHER DIRECTION
• Solenoid coils may be burned out. Replace.
• Solenoid service valves may be closed. Open.
• Manually actuate solenoid. If slide stop will not move mechanical problems are
indicated. Consult Johnson Controls - Frick Service.