Simplex Double-Sided Clock Removal

January 7, 2013 10:20 AM

I have (legal) access to a building slated to be demolished and can take whatever I want. Specifically I want to remove a Simplex clock Similar to the one here.

It's currently running and I do not have access/ability to shut off power to the clock. Will I have a problem just cutting the wires after I unbolt it from the ceiling? Is it safe, as in low-voltage? If not, what can I easily do to remove it without getting shocked?

posted by a_green_man to home & garden (7 answers total)

It is probably running off of 110v service. If there are wire caps, then undo them and pull the wires apart. Put the caps back on the service wire as you remove them and tape them. Be careful of touching the bare wires. Easy peasy.

If there are no wire caps, you can cut the wires (mostly) safely. Wear gloves and use rubber handled linesmans pliers or some other wire cutter. For extra safety, use a fiberglass or wood ladder. Make the cut cleanly and without excess touching of the live wires. Cap them when you are done.

Point is - don't be the path to ground.

Bring a friend and a wooden cane. The cane is to pull you away should something go awry.

This is not risk free - 110V can kill you. But you can mitigate much of the risk with some care.
posted by Pogo_Fuzzybutt at 10:46 AM on January 7 [1 favorite]

I can't tell from that site, but it seems like to even function at all or set the time, you will need some method of communicating with the clock.
posted by MonsieurBon at 10:46 AM on January 7

I think this post is about saving the hardware, not getting it all up and running again.

That said, I believe this would have run off of a main panel, such as in the school office or similar, that should be separately capable of being disabled. Surprising that you wouldn't be able to do that, especially if you brought someone knowledgeable with you. I'm also a bit surprised they would let you do this if THEY did not turn off mains first. Anyway, I have some indirect experience dealing with demo crews and they are often very protective of what is soon to be dust. Then again, there's Richard Nickel.

Obviously, to reiterate, 110V can kill you. (Incidentally, the photo set shows a UL notice with 120V required.) Precautions above are obvious. You can also get electrical hazard work boots, though they'll set you back $150 or more. If it's just one clock, probably not worth that investment, but what's your life worth?

One thing that might help is practicing with a disconnected circuit. It depends, though, because you don't know how the wiring was done before you get there. If it was done really properly, the wires can be so tightly wound together inside the pigtail that you need a pliers to undo them, and then it's really tricky if you're working live. (I've never done that.) I have done things like tighten screw connections on a live receptacle, and I have gotten shocked. Whatever you do you don't want to be somehow in a position to lose control of your body and then collapse or just freeze where you're still in electrical contact. Think before each step. Maybe pile some cardboard boxes under your ladder so you don't injure yourself in a fall (voluntary or involuntary).
posted by dhartung at 11:05 AM on January 7

These types of clocks will indeed run without the master clock, the page that OP links to seems to confirm this.

What happens is that the clocks happily run on their own using the 120VAC feed, then receive a high-frequency signal from the master clock at the top of an hour. This "clutch" circuit receives the tone and a solenoid slams the minute hand up to :00, thereby synchronizing all the clocks in the building.

Some people have hacked up their own little boards to send out this signal on the hour to their salvaged clocks, but it should keep pretty decent time without it anyway.
posted by JoeZydeco at 11:48 AM on January 7

Call a professional electrician and pay their hourly rate to come out and do it. It's not worth the risk to your safety and it would probably be cheaper than the aforementioned work boots.
posted by troika at 11:48 AM on January 7 [2 favorites]

DON'T cut both wires at the same time. The cutter jaw will bridge the conductors, and then you're shorting as much current as the upstream equipment can supply. I have a little spot on my retina from the flash when I did this once, and the gouge taken out of the cutter jaw is pretty amazing. (I don't have a pic handy, sorry!)

DO cut one wire at a time, and cap it before cutting the other. Cut them at staggered lengths so that if the caps fall off, the free ends don't touch.

"Insulated" cutters are expensive, but realistically the rubber-dipped handles on regular tools are fine for 120v. It can't hurt to wear gloves. Make sure the metal parts of the cutter don't contact any other exposed metal (frame parts) during the cut.

Or just walk into your local hackerspace (you're in the bay area? they're all over!) and grab any random electrical badass to accompany you.
posted by Myself at 10:55 PM on January 7

Mission accomplished!

Being innately fearful of electricity, I was a bit nervous going in. I brought rubber soled shoes, a thick rubber mat to stand on, used rubber coated tools and wore rubber gloves. Probably overkill: it went pretty easy since it had wire caps on it and didn't kill me :)

Thanks for the directions folks, and I do appreciate the "find a pro" comments as well, I just really wanted it for free and only had about a two hour window to get it.

Here's a pic as your reward.

If anyone, like JoeZydeco, has any links or more info on setting up the time sync, I can forward it on to my brother. It's a gift for his shop.
posted by a_green_man at 2:00 PM on January 8 [1 favorite]