Magnetic locks losing power occassionally

[katwalatapan]

Hello,

I have a peculiar case where voltage fluctuations either originating at the facility or via the utility is causing magnetic locks at a facility losing power during some instances.

I wanted to inquire if the mag lock could lose power if a transformer that feeds the secondary line supply voltage to a magnetic lock receives a voltage surge/drop on its primary line.

This voltage surge/drop may be from the utility transformer or from the standby generator if there is an issue with its automatic voltage regulator.

Would there be any other reasons for voltage spikes/drops that may cause a mag lock to lose power and then come back on sporadically?

Thank you.

Regards,

Tapan Katwala.

 

[jraef]

I think it is going to depend on the nature of your "magnetic locks".

If they are ELECTRICALLY HELD (electromagnetic) locks, then any brief interruption of power will cause them to drop out, but then they should re-lock when power is restored.

If on the other hand they are Magnetically Held, as in Permanent magnet, locks, then there would be two electromagnetic coils to engage or disengage the mechanism. If that's the case, then a momentary pulse of power to one side or the other could definitely cause inadvertent operation. Typically, there would be protections against such an incident in the control system design. I did a lot of prison lockdown control systems, we isolated EVERYTHING as a precaution against just that sort of thing. If that is what is happening for you, someone likely didn't think the system through very well and that needs further exploration.

"Will work for (the memory of) salami"

 

[LiteYear]

I wanted to inquire if the mag lock could lose power if a transformer that feeds the secondary line supply voltage to a magnetic lock receives a voltage surge/drop on its primary line.

Basically... yes. Vs ∝ Vp, so if Vp changes, so does Vs. Since Vp is almost guaranteed to fluctuate (there's various standards that put bounds on those fluctuations), Vs will fluctuate too. Since this fluctuation is expected, the design will be expected to tolerate it. So I think the real question is, is the power supply fluctuation immunity in the mag lock design appropriate? It would seem unusual to me to design a mag lock to release on surge/droop.

 

[mikekilroy]

it might also be appropriate to consider how many locks there are and if all do this or only 1 or some? Are they on same or different breaker feeds? Did it always do this or just start recently? Like any electric device, it can fail (open coil, shorted windings) or only happen when bumped if loose connection. If at least one works try swapping its coil with the failing one? Might also consider a UPS on the supply to it (them) if this drop out is important.