Climate Control

HVACR Tech Tip: Troubleshooting Solenoid Valves in Refrigeration Applications

HVAC Tech Tip: Troubleshooting Solenoid Valves in Refrigeration -Solenoid valve products - Sporlan Division Parker Hannifin ​To ensure peak performance, solenoid valves must be selected and applied correctly; however, proper installation procedures are equally important. Aside from correct installation, troubleshooting the typical malfunctions is something all HVAC technicians should know.

Learn about the three typical malfunctions and download our installation and servicing guide for reference.

 

Typical malfunctions 

There are only three possible malfunctions:

  1. Coil burnout.

  2. Failure to open. 

  3. Failure to close. 


Coil Burnout 

HVAC Tech Tip: Troubleshooting Solenoid Valves in Refrigeration Applications - Solenoid anatomy cross section - Sporlan division Parker HannifinCoil burnouts are extremely rare unless caused by one of the following:

  • Improper electrical characteristics. 

  • Under-voltage of more than 15%. This applies only if the operating conditions are such that the reduced MOPD causes stalling of the plunger, which results in excessive current draw. 

  • Incomplete magnetic circuit due to the omission of parts such as the plunger on the PKC molded model coils. 

  • Mechanical interference with plunger movement which may be caused by a deformed enclosing tube. 

  • Voltage spike.

  • Valve ambient exceeds 120°F.

  • Fluid or gas temperatures greater than 240°F, while the valve ambient is 120°F.


Failure to Open

(Normally Closed Types)

  • Coil burned out or an open circuit to coil connections. 

  • Improper electrical characteristics. 

  • In pilot operated valves, dirt, scale or sludge may prevent the piston, disc or diaphragm from lifting. This could also be caused by a deformed body. 

  • High differential pressure that exceeds the MOPD rating of the valve. 

  • Diameter reduction of synthetic seating material in pilot port because of high temperatures and/ or pressures, or severe pulsations.
     

The problem of dirt can be avoided by installing a Sporlan Catch-All® Filter- Drier upstream from the solenoid valve. The Catch-All® Filter-Drier will retain much smaller particles than a conventional strainer. Use a Sporlan strainer for water applications upstream of every industrial solenoid valve.


Failure to close 

  • Valve is oversized.

  • In pilot operated valves, dirt, scale or sludge may prevent the piston, disc or diaphragm from closing. This could also be caused by a deformed body. 

  • Held open by the manual lift stem. 

  • In pilot operated valves only, a damaged pilot port may prevent closing.

  • A floating disc due to severe discharge pulses.

  • Have voltage feedback to the coil after the coil de-energizes.

HVAC Tech Tip: Troubleshooting Solenoid Valves in Refrigeration Applications

Miscellaneous contributors

Liquid Hammer – Industrial solenoid valves, or other liquid line valves, may cause liquid hammer when installed on liquid lines with high liquid velocities. If this occurs, it can be minimized by the use of larger pipes, (i.e.lower velocities), or a standpipe installed in the piping near the solenoid valve inlet. Commercially available shock absorbers may also be used to reduce this noise. Recommended maximum velocity is approximately 300 fpm.

AC Hum – This problem may be caused by a loose coil. A loose coil hex screw or coil locknut may cause this problem on the MKC molded model coils. Foreign material between the magnetic top plug and the plunger in the Types A3, E3, W3, E5, B6, E6, W6, E8, B9, E9, B10S2, E10S1, E10S2, B14, E14, W14, B19, E19, W19, B25, E25, W25, E35 and E43 Series Solenoid valves may cause AC hum also.

Water applications - Deposits may accumulate in the valve which could cause AC hum. This may be eliminated by cleaning or flushing the valve. 

 

HVAC Tech Tip: Troubleshooting Solenoid Valves in Refrigeration Applications - Cover image of Solenoid valve s- installation and servicing instruction s - Sporlan Division Parker Hannifin

Download the complete guide for installation and servicing instructions for solenoid valves

 

 

 

 

 

 

 

 

 

 

 

Jim Eckelkamp

HVACR Tech Tip Article contributed by Jim Eckelkamp Solenoid Product Manager,  Sporlan Division of Parker Hannifin

Additional resources:

Use of Suction Line Filter-Driers for HVAC Clean-up After Burnout

Clean-up Procedure for Refrigeration and Air Conditioning Systems

HVACR Tech Tip: Guide to Servicing Blended Refrigerants

Compressor Overheating Is the Number-One Refrigeration Problem

 

 

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