Why is the Von Duprin PS873 power supply buzzing or chattering?

Some transformers in the power supplies provide a little humming noise and that is normal. If the humming in Von Duprin PS873 power supply is loud follow these steps.

  1. Remove the load from the output of the power supply and see if the humming stops. If  it does, You may have grounding or over load issue.
  2. Verify PS873 is putting out 24VDC plus or minus 10%.  The buzzing could be caused by the main board putting out excessive voltage.  If this is the case you will need to replace the PS873 main board and if not available move to the PS914-XX supply and new option cards.
  3. The potted module at the electrified exit device may be faulty.  Check voltage out of potted module on green and yellow.  Should measure 0, if holding voltage on yellow indicates pull coil is remaining energized and pulling power supply down, replace the potted module.
  4. If using a battery backup board, overcharged batteries may cause the power supply to chatter. Disconnect the batteries and see if the chattering will stop. If it will, remove AC voltage and connect the batteries and let batteries to operate the hardware for awhile.

DISCLAIMER:

INFORMATION PROVIDED THROUGH THIS SITE IS PROVIDED TO YOU AS IS WITHOUT ANY EXPRESS REPRESENTATIONS OR WARRANTIES OF ANY KIND, AND WE MAKE NO REPRESENTATION OR WARRANTY THAT THIS SITE(OR ANY INFORMATION PROVIDED IN RESPONSE TO YOUR INQUIRY), WILL BE ACCURATE, COMPLETE, OR ERROR-FREE.

YOU AGREE THAT YOU MUST EVALUATE ALL INFORMATION AND RESPONSES, AND THAT YOU BEAR ALL RISKS ASSOCIATED WITH, THE USE OF THIS SITE, INCLUDING ANY RELIANCE ON THE ACCURACY,COMPLETENESS, OR USEFULNESS OF ANY INFORMATION OR MATERIALS MADE AVAILABLE THROUGH THIS SITE.

Other users ask

Question