66043014 © Geocislariu | Dreamstime.com
Learning how to recognize and avoid common failures with solenoids can help to minimize unplanned machine downtime.

Solenoid Troubleshooting Checklist

July 25, 2023
Learning how to identify common causes of solenoid failure and how to prevent them will help to reduce unplanned downtime.

Solenoids are an important device which help convert electrical energy into mechanical work. Understanding how to identify and fix potential issues which may arise with a solenoid helps to ensure proper repairs are made and larger machine issues can be prevented.

The following solenoid troubleshooting checklist outlines some of the key failures which can occur with solenoids and how to address them. 

Issue 1: Overheating

When a solenoid is first energized, its coil receives a pulse of high inrush current that decreases as the plunger closes. If the plunger does not close, the high inrush current continues, which can cause the coil to overheat and burn out. This is the most common cause of solenoid failure and spotting it is easy.

When a coil burns out, the nylon bobbin upon which it is wound melts and runs into the air gap under the plunger. If you find melted bobbin material, see if the plunger was mechanically blocked open. On a double-solenoid valve, see if both solenoids were energized at the same time. (Magnet wire insulation wire may burn too).

Standard coils are rated class 105°C (221°F), so they can safely reach and sustain temperatures slightly hotter than boiling water. Thus, a solenoid too hot to touch may not be overheated.

A drop in supply line voltage can prevent a solenoid from closing by reducing its force until it can’t overcome the load’s resistance. Check the line voltage over a 24-hour period.

If ambient temperature is too high, the coil’s ability to dissipate heat by radiation is reduced. An overheated coil’s resistance increases, current flow and force are reduced, and the solenoid will not close, resulting in coil burnout again.

Check the cycling rate. If a solenoid cycles too fast, heat will build up faster than it can be dissipated. The solenoid becomes too weak to close, so it receives a continuous high inrush current and burns out.

READ MORE: Why Solenoid Coils on Hydraulic Valves Burn-Out

Issue 2: High Voltages

In rare cases, a solenoid coil will burn out due to over voltage. The plunger closes easily because the solenoid has extra force, but high voltage causes excessive holding current, which overheats the coil gradually and burns insulation on the magnet wire. There is no melted bobbin in this case.

Issue 3: Shorting 

Another possible cause of solenoid coil burnout is shorting. Water-based coolants often carry fine metallic particles. Accidental splashing or soaking of the coil’s lead wire junctions can cause short circuits.

Issue 4: Damage

Finally, a solenoid can hammer itself to pieces — evidenced by mechanical damage and breakage. Excessive force can be caused by overvoltage or by a reduced load on the solenoid and must be absorbed when the plunger hits the C-stack or field.

Determine the cause of damage before replacing a solenoid. Its force should closely match the load.

This material was extracted from “What is a Solenoid?”, a free brochure previously available from ROSS Decco (formerly known as Detroit Coil Co. [Decco]).

Continue Reading

Common Modes of Failure for Hydraulic Piston Pumps

Oct. 13, 2021
Learning how to recognize and proactively maintain the four most common modes of failure for hydraulic piston pumps will reduce unplanned downtime.

A Guide to Recognizing the Causes of Hose Failure

June 26, 2023
When a hose failure occurs, identifying what the problem is and taking appropriate steps to correct it will help to minimize system downtime in the future.

Sponsored Recommendations

MONITORING RELAYS — TYPES AND APPLICATIONS

May 15, 2024
Production equipment is expensive and needs to be protected against input abnormalities such as voltage, current, frequency, and phase to stay online and in operation for the ...

Circuit Protection Devices & Busbars

March 13, 2024
With experienced Product Engineers and Customer Service personnel, Altech provides solutions to your most pressing application challenges. All with one thought in mind - to ensure...

All-In-One DC-UPS Power Solutions

March 13, 2024
Introducing the All-In-One DC-UPS, a versatile solution combining multiple functionalities in a single device. Serving as a power supply, battery charger, battery care module,...

Motor Disconnect Switches

March 13, 2024
With experienced Product Engineers and Customer Service personnel, Altech provides solutions to your most pressing application challenges. All with one thought in mind - to ensure...