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How to know when utility power returns with a manual transfer

How to know when utility power returns with a manual transfer

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  #1  
Old 09-21-11, 05:59 PM
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How to know when utility power returns with a manual transfer

Recently I installed an new interlock deadfront on my 200 amp CH panel. The 50 amp generator breakers are fed by an 50 amp inlet that is right beside main panel which is located outdoors. I even pulled the permit and passed the required inspection. The only problem with this setup or any manual transfer setup for that matter is that I wont know when utility power has returned when operating on the generator.

I know Reliance makes a "Power Back" widget that you wrap around one of the service conductors and it beeps when utility power returns, however I cant really use that on my outdoor panel very easily.

My current plan is to tap one of the 2/0 service conductors with a 14 gage tap and then use a half amp inline fuse before I run the 14/2 nm about 30' to the utility room where I would connect it to a switch and then a doorbell transformer with a buzzer attached. I figure this would cost me less than 60 bucks in parts. 230.82 seems to suggest this would be legal, but somehow I doubt it.

If anyone has a better or easier way to do this, I am definately open to suggestions.
 
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Old 09-21-11, 06:35 PM
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Wouldn't you have to pull the meter to install the tap? How about using CTs (current transformers) to do something similar? You can get split CTs, although they are fairly expensive.

Otherwise how about buying the PowerBack and dissecting it? More than likely you can figure out how to do a remote light and audio with 30 ft of 18 or 16 AWG.
 
  #3  
Old 09-21-11, 06:51 PM
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First issue I see is your tap:
1) You may not have more than one wire under one screw. No matter what the size.
2) Your tap conductor is too small. You would need at least #12 for a 200 amp service. You may run #14 after the fuse. Not before.

Better Idea? How about just watching your neighbors house?
 
  #4  
Old 09-21-11, 07:01 PM
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I was going to "gutter tap" it with this:

https://images.tradeservice.com/OMHP...BE00007_13.pdf

I found them for about 10 bucks. I could easily do 12 ga to the fuse then 14 ga. after. Do you see any other problems?

I thought about using split core CT's, but with no current flowing I cant see how to make it work.
 
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Old 09-21-11, 08:50 PM
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Originally Posted by Auger01 View Post
I was going to "gutter tap" it with this:

https://images.tradeservice.com/OMHP...BE00007_13.pdf

I found them for about 10 bucks. I could easily do 12 ga to the fuse then 14 ga. after. Do you see any other problems?

I thought about using split core CT's, but with no current flowing I cant see how to make it work.
That kind of tap would be acceptable. You would only need one since the neutral is not disconnected and you could just come off the neutral bar.
I also though about using CT and ran into the same issue as you did. No current with the main off.

The only other issue I can see is the circuit created by the tap would need some type of readily accessible disconnecting means as your basically creating another service. Rather then an in line fuse (I'm envisioning a barrel type fuse and holder), which would be required to be inside an enclosure, install a single fused disconnect or breaker. A 30 amp (with 15 amp fuses or less) fused A/C disconnect might be a good option as they are quite inexpensive, and weatherproof, so you can mount it outside next to the panel. All service disconnects are required to be grouped.
 
  #6  
Old 09-22-11, 07:15 AM
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Originally Posted by Auger01 View Post

I thought about using split core CT's, but with no current flowing I cant see how to make it work.
Good point!

How do they do it with an automatic transfer switch? Just check for voltage?
 
  #7  
Old 09-22-11, 10:51 AM
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The auto transfer switches usually have a signal processor that not only checks for voltage but also makes sure it's a stable waveform for a few seconds before transferring back to line power.

I have wired up a few with a just a 120V panel mount LED between the mains to indicate line power. The wire that comes formed into the LED is like 24 AWG so you can just fold it a little and tuck it into one of the lugs. It's probably not 100% code, but I don't really see what could go wrong with it as it draws something like a couple milliamps and the 24AWG would fuse before an actual fuse.
 
  #8  
Old 09-22-11, 02:10 PM
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For my (Generac) ATS/genset, I think it is actually the controller in the genset that senses utility power or lack of. There are fused taps on both buss bars in the ATS after the utility service disconnect. Both taps/wires go to the controller in the genset. The location of the taps are "before" the actual ATS switch mechanism, such that the position of the switch (utility power or genset power) doesn't affect the presense of power on the taps/wires going to the controller as long as the utility service disconnect has not been thrown manually (or automatically due to overcurrent).

Some people who like to put a real load on their gensets during weekly exercise will fake a power outage by pulling one of the fuses. The genset controller sees utility power lost on one leg, so it will start up the genset and cause a transfer, even though utility power was not lost. When it's time to stop the exercise, the fuse is put back in, and 15 seconds later, the genset controller will cause a transfer back to utility power. The advantage of doing the exercise this way (in addition to exercising with a load) is that the power transfers are fast enough that clocks don't notice it so they don't have to be reset. The downside is that it is a manual process. I've considered doing something similar using a relay instead of pulling the fuse, and controlling the relay with my home automation system.

I think Generac gensets are somewhat unique with regard to the genset controller calling for the transfer instead of the ATS itself.
 
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Old 09-22-11, 04:12 PM
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I have wired up a few with a just a 120V panel mount LED between the mains to indicate line power. The wire that comes formed into the LED is like 24 AWG so you can just fold it a little and tuck it into one of the lugs. It's probably not 100% code, but I don't really see what could go wrong with it as it draws something like a couple milliamps and the 24AWG would fuse before an actual fuse.
That's what I have, too. Except mine is neon. Bought'em at the big box electronics store.
 
  #10  
Old 09-22-11, 06:53 PM
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Wow. Watching the neighbors house doesnt seem so bad at this point.

If I did do the AC disconnect box, would I need to run a seperate wire to the grounding rod for it?
 
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Old 09-22-11, 06:54 PM
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I think Generac gensets are somewhat unique with regard to the genset controller calling for the transfer instead of the ATS itself.
That's exactly right. Most commercial/industrial standby power systems have the brains in the transfer switch, but Generac puts the brains in the generator controller at least they do in the smaller natural gas and propane machines. Not 100% certain, but I believe the diesel Generacs have the brains in the transfer switch too. Don't see many diesel Generacs around here.
 
  #12  
Old 11-02-11, 08:03 PM
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I just had a manual interlock kit installed, and would also like to have some way of telling me that power has returned (hard to see the neighbors house from here).

The electrician said he could have installed a light connected to the main somehow, and I wish I had him do that, but it wil be tough to get him to come back to do something that small.

Reliance made a Powerback device that was supposed to beep when power returns, but that has bene discontinued.

Can I use a non-contact voltage detector to test to see if voltage has returned?
 
  #13  
Old 11-02-11, 08:11 PM
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Originally Posted by placekicker View Post
Can I use a non-contact voltage detector to test to see if voltage has returned?
Sure, You will have to get it close enough to the wires to set it off. Test it before hand to find a place to set it.
 
  #14  
Old 11-02-11, 09:46 PM
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Thanks - a voltage sniffer seems to be the cheapest way, although I'd love to have a buzzer or LED light wired to the main somehow (if that's possible) and run upstairs when I get richer.
 
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Old 11-02-11, 10:18 PM
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  #16  
Old 11-02-11, 11:57 PM
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Uh, Mike, did you not notice that every one of those links stated the device had been discontinued?
 
  #17  
Old 11-03-11, 08:16 AM
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Uh, Mike, did you not notice that every one of those links stated the device had been discontinued?
Yes. Discontinued from reliance right? But I am sure all those links have them in stock if you went to order one. Or I am sure some companys has them sitting on the shelfs.


You know from looking at it, I would say they are discontinued because people were may have been ending up "DEAD" trying to install it..... I assume you need to pull the meter.

Mike NJ
 
  #18  
Old 11-03-11, 01:06 PM
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I actually did try to order from one of the links, at least to the point where I would have entered my cc info, and it came back that it was discontinued. I assumed that meant that it not only was discontinued by the manufacturer but was also unavailable from the distributor.

Maybe these companies need a better webmaster to delete items from their on-line catalogs when they are not available.

I also assume that you are correct, that Reliance discontinued it because of the extreme hazard involved in a DIYer (or clueless electrician) attempting to install without having the utility disconnect the incoming power. It is also possible that Reliance not only discontinued manufacturing the device but also required their distributors to return any unsold devices. That would not be uncommon with a device deemed to be hazardous.
 
  #19  
Old 10-06-14, 05:50 AM
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Needs to be wireless

I made the best of both. I mated a non-contact AC voltage detector to a cheap wireless doorbell. Attach the voltage detector with Velcro to one of the insulated 120V AC legs coming into the main breaker. The AC voltage detector triggers the wireless transmitter when power returns and "voilą" the wireless doorbell goes off. Carry the doorbell receiver with you where ever you go, leave on night table to wake you up, or leave in kitchen (central part of house). No need to have to keep checking a light or listen for faint alarms.

Best of both!
 
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