Very Hot Electric Strikes

I was in a newly constructed building today that has a few locations of EAC. Nothing special, basic looking electric strikes. Unsure of brands but I'll be back there next week and will check it out in more depth. I brushed against one of the strikes walking in, and it was very hot. I then checked out a few others out of curiosity, and they were all hot. Pretty much burn level hot. Something...

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Was it a new or old unit?

Especially when strikes get older, the coil pack in the solenoid becomes less efficient. Over time, the potting inside the solenoids melt and 'burn-in', and usually they draw more amperage to do the same work.

In my experience, when they get hot like that, the 'end is near' and it might have days or weeks left before giving up the ghost.

I also remember one application with a NEW solenoid that ran hot because the power cable was a really long run. I think 75' - 85'.

The strike manufacturer troubleshot this, and explained that due to voltage drop in the long run, the solenoid never 'bottomed out' and floated. Even though the strike released well, it never completed a cycle, and always drew a small amount of power....

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Do you know if they are fail safe or fail secure? Fail safe electric strikes have a constant 24V to the lock to keep it in the secure position. This will cause the locks to run hot. If the electric strikes are hot (burn the skin), then you have a bigger issue.

My money (for as much as an over-the-internet diagnosis is worth) is on over-voltage - a strike designed for 12VDC being run on 24VDC, for example. If it's a particularly long run, it's possible it wasn't operating properly at 12VDC due to voltage loss, and someone decided it would be a good idea to give it 24V as a work-around (don't laugh, I've seen it).

24V constantly energized strikes run with 12V power supply. At half the voltage, you need twice the current to do the same work. Double the current, double the heat.

Correct voltage with very long and/or smaller gauge cable can also do this.

Ummm... current would be limited by the DC resistance of the coil. Same load at half the voltage would be half the current. I=V/R.

No, in this case, flip that:

With a purely resistive load, the relationship between voltage and amperage is directly proportional like Matt suggests. If one increases so does the other proportionately.

However, with an inductive load (even a DC coil, like a solenoid) the...

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I will do what I can to get more details on the issue and share the findings. It's someone else's system so my poking may be limited but it was a curiosity. Lots of good info here; thank you all. Someone will win a cookie.

New construction.......energized strikes (open doors and very hot). Bet the strikes are rated for "intermittent duty" and they are being fed continuosly making them run super hot. That is definitely a fire hazard....at the panel! Depending on the relay rating doing the switching, more and more current is being pulled thru them so its just a matter of time before they burn letting out all...

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From HES FAQ website:

Is it normal for HES electric strikes to heat up during continuous duty?

Yes, all electric strike solenoids will heat up, especially...

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I concur with this post. We always use the SMART PACs as well if the HES strike will be unlocked for hours.

When we first installed the strikes in the new building at my old job (HES 1006), we noticed they heated up, as well. Some thought to the point of burning. I didn't think they were that bad. We did use the Smart Pac III on some projects, though, and it did help with it. They still get warm, but not hot.

Heat is the killer of all electronics. Another related feature of the smartpak is that it fires the strike at the higher voltage (12 or 24) then runs at a lower 9 or 18 volts after 2 seconds. Also has built in diagnostics.

See the

I've seen this problem before, and it's a simple fix if the hardware allows. Electric strikes are typically used as fail-secure, and stay locked when not energized - they open with a shot of energy from the controller. If the application requires the door to remain unlocked most of the time, then a lock with a fail-safe hardware setting (usually a toggle or turn-screw) will be used. It...

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Assuming it is just an issue with the strike under constant power (during the day for example) and all else is correct, I see where that would be good during the day, but then you have the reverse problem at night and it gets hot at night. Plus, you fundamentally change the security situation upon loss of power with that modification.

I ended up there on Friday and rounded up some additional information. Note: this is not our building so I was trying to maintain a light footprint.

  • Building: 3 story, 65K SF
  • Strikes are HES 1006CLB-12/24D-630
  • Voltage being supplies was 27.44VDC at one test point relatively close to the PS. It appears that it's all powered and controlled from a single...

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Since those are a dual-voltage strike, I'd look into whether they're wired for 12V operation:

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It was the 24VDC tail. Sorry, should have included that.

Negative: It's set for fail secure and is engergized during some hours of the day to allow for free, non-card, access during those times. It fits for this application.

Ah... sounds like everything IS (theoretically) as it should be, then... which makes this a real mystery!

I experienced the same thing with the same strike. Hard to swallow 140* is "normal" not to mention 171* is hot enough to burn skin.

Folger Adams, Adams Rite, and Vonduprin strikes I have used get warm but not like that.

Smartpacs fixed the problem although 19X$38= a big chunk of my profit.

Something else you can do is if the strike is an AC version (i.e. just a coil for the solenoid) and you feed it with DC it will seem to work ok but the AC solenoid is constructed with less coil wire causing a lower resistance and hence more heat then failure. You can minimise this by sticking a diode (like a IN4007) across the coil. make sure the positive from the supply goes to the anode...

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Smart Pac all the way. It lowers the voltage draw after the strike opens to reduce the heat. We were called into a school after their integrator installed a hundred of them and one of the kids got burned after leaning on it.

Hopefully you have enough room in the stike pockets to wire it in there or you are going to be doing a lot of cleaning out.

Hmmm Smart Pac seems to be a good product....

in-line power control that is able to receive input voltages from 12 to 32V AC or DC. bridge rectifier. Continuous duty timer reduces initial voltage by 25% to extend the life of the electric strike. Includes built-in resettable fuse, MOV, voltage regulation and input status LED....

HES 2005M3: SMART Pac III™

If the Doors need to be kept open for long times ... Wouldn't maglock be the better solution? Does it have to be strikes?

Strikes are much less likely to require inspection and tying into fire alarm systems for override in emergency.  Strikes are usually much less expensive.  Also, fail secure strikes will function in their security roll long after the battery drains on a maglock power supply during power outages.

This post makes me cringe almost to the point of vomiting. Resisting the urge to hammer the "disagree" and "unhelpful" buttons. :)

Maglocks should never, ever be used by anyone serious about access control, except as an absolute last resort.

Ever.

EV-AR.

This post makes me cringe almost to the point of vomiting. Resisting the urge to hammer the "disagree" and "unhelpful" buttons. :)

I for one would have preferred you used the buttons...