I was recently called to one of my Institutional customer after there front doors electric strike would not lock and the electric strike was in locked open position after a tap it dropped closed and I found the mechanism was wearing out and needed replaced. but in replacing the lock I found what has been an on going problem with the lock not opening or partially opening or not closing when button was released.
What was happening was that when the door lock was first installed it was powered by 24 Volts AC power but some where along the way some one change the lock over to 24 Volts DC as the AC powered locks can be very noisy when they operate.
There is nothing wrong with doing this as long as it is done properly.
and in this case it was not . What the person installing the DC lock did was cheat and use a half wave rectifier which had no filtering which produced raw AC/DC power not a good thing to use on an electromagnet and to make matters worse he installed the rectifier in the door jam which made it vulnerable to temperature swings which is why when the door frame got extremely cold or hot it would misbehave also the constant power on power off was not good for this component it is meant to be powered continuously.
I put in a new lock and removed the half wave rectifier and inside I installed a proper filtered DC power supply next to the power transformer and installed surge protectors and door operates with no further problems. I also put in back up battery s as the door lock is used as part of a door access system and unknown to institute was fact when the hacks who put the access system in improperly also never checked to see if door would work during a power failure .
But this is what happens when you hire so called professionals and not properly check them out.
Thanks for posting the useful information to my vision. This is excellent information,.
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