ELR Humming Instead of Retracting - Troubleshooting Guide

Answer

Diagnostic Checks

1. Mechanical Binding at the Strike or Rods

   Excessive mechanical resistance may prevent latch retraction.      

    Check for the following:

   • Latches rubbing against the strike
   • Vertical rods not centered
   • Vertical rods misaligned or skewed
   • Top rod out of adjustment

   If any binding is present, correct the mechanical alignment and re-test. 

2. Yoke Assembly Pin Condition

    A misaligned or damaged yoke pin can prevent proper solenoid movement.

   Inspect the yoke assembly pin for:

   • Misalignment 
   • Rubbing
   • Burrs or surface damage

   If damage or interface is found, correct or replace the affected components. See Image in Additional Information Section Below. 

3. Electrical Resistance in Wiring

   Excessive resistance can prevent the solenoid from developing sufficient force.

   Test Procedure:

   1. Turn off power to the ELR150 power supply
   2. At the terminal block 2, measure resistance across:
      • Pin 1
      • Pin 2 (white wires)

   Expected Measurement:

   • Resistance must be between 4.5 and 6.0 ohms

   If resistance is outside this range, inspect wiring and connections for faults.

Applies To

 ELR, Electric Latch Retraction, APEX 2000
 

Additional Information

Yoke Assembly Pin Location Description

• The pin is positioned on the yoke assembly, which connects the solenoid plunger to the latch retraction mechanism.
• It is located at the joint where the yoke arm pivots during solenoid activation