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Manual transfer switch for portable generator question.

acer66

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Hi there,

I want to wire in a manual transfer switch for my portable generator which provides 30A for my house.
The biggest load will be the fridge, I think, since heating of house and water is done with natural gas.
Seems to be straight forward but the to me big price differences between switches leave me a bit puzzled.

Can anyone shed some light on that and what look out for in the whole set up and while we are on the topic,
is there a code for how far a portable generator has to be away from a above ground propane tank?

Thank you.
 
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Jeff95TA

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The prices of the two you showed are about the same, and appropriate for what you're trying to do. What were you looking at that had a big price difference?
 
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acer66

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The prices of the two you showed are about the same, and appropriate for what you're trying to do. What were you looking at that had a big price difference?

Yeah, I think my research skills today sucked and I went into a rabbit hole.
At one point I was looking at upgradable switches and so on.

Maybe I can rephrase my question in the way if there are brands to avoid or to prefer.

Thank you.
 

larry4406

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I would put a panel cover interlock kit on. Prevents the main and back feed breaker from being on simultaneously.

Install back feed breaker of proper rating. Some need a clamp to secure the backfeed breaker to the panel.

Wire a power inlet sized to your generator.

You will have to manage your house loads manually.
 

highland_hunter

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Ever consider a double throw safety switch?

I have limited electrical requirements at my house and had an electrician wire one up for me and run my entire house on a 7500w portable. (gas heat, stove, dryer, etc and all LED lighting)

Cheaper option for what your looking to do.
 

Jeff95TA

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I inquired with my power company about the interlock and they wouldn't accept it since it wouldn't prevent a failure of the main breaker. The transfer switch is a break-before-make setup.

I know the odds are slim of a main breaker failing in that manner, and I didn't want to find out what the ramifications could be, so I went with the transfer switch.
 

alexb2000

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I know this is heresy, but I have run my portable generator many times off a normal 220 plug. Turn off the main breaker and start the generator. Yes, a manual switch is better. Yes an interlock is better. Yes, an automatic transfer switch is better. I could go on, but this is in the event of an emergency with a small portable gen.. If you are really worried about a main breaker failing you could just pull the meter. At least I'm being honest about it.

....waiting on safety lecture
 
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acer66

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I know this is heresy, but I have run my portable generator many times off a normal 220 plug. Turn off the main breaker and start the generator. Yes, a manual switch is better. Yes an interlock is better. Yes, an automatic transfer switch is better. I could go on, but this is in the event of an emergency with a small portable gen.. If you are really worried about a main breaker failing you could just pull the meter. At least I'm being honest about it.

....waiting on safety lecture

Looks like you already did that yourself. :lol_hitti:beer:
 

rlitman

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I inquired with my power company about the interlock and they wouldn't accept it since it wouldn't prevent a failure of the main breaker. The transfer switch is a break-before-make setup.

I know the odds are slim of a main breaker failing in that manner, and I didn't want to find out what the ramifications could be, so I went with the transfer switch.

An interlock is also a break-before-make setup. The only difference between an interlock and another manual transfer, is that the interlock uses breakers as switches (actually, so do many other manual interlocks).
 

wyliesdiesels

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I inquired with my power company about the interlock and they wouldn't accept it since it wouldn't prevent a failure of the main breaker. The transfer switch is a break-before-make setup.

I know the odds are slim of a main breaker failing in that manner, and I didn't want to find out what the ramifications could be, so I went with the transfer switch.

Is your PoCo also your AHJ? I highly doubt it and if not then they dont have much say in that.

I know this is heresy, but I have run my portable generator many times off a normal 220 plug. Turn off the main breaker and start the generator. Yes, a manual switch is better. Yes an interlock is better. Yes, an automatic transfer switch is better. I could go on, but this is in the event of an emergency with a small portable gen.. If you are really worried about a main breaker failing you could just pull the meter. At least I'm being honest about it.

....waiting on safety lecture

Thats a great way to kill a lineman.

And is this 240v(220v doesnt exist anymore) outlet 4-wire? if not then how did you wire a 240v generator to a 3-wire 240v outlet?

Also, pulling the meter is not a good idea either for many reasons.

Please dont give this kind of horrible advice on here.
 

Bretny

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In my area the only way the PoCO gent involved in generators if your putting in one one of those on meter style transfer switches.

Use an interlock and not have to pre choose your circuits that run on the generator.

Use to small of a transfer switch and chances are your still going to have extension cords running around. Im assuming this is part of why your wanting a transfer switch in the first place, as your loads all look like they could be 120v.
 

alexb2000

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Is your PoCo also your AHJ? I highly doubt it and if not then they dont have much say in that.



Thats a great way to kill a lineman.

And is this 240v(220v doesnt exist anymore) outlet 4-wire? if not then how did you wire a 240v generator to a 3-wire 240v outlet?

Also, pulling the meter is not a good idea either for many reasons.

Please dont give this kind of horrible advice on here.

An interlock is a $50 piece of sheetmetal that prevents turning on the breaker connecting the generator to the panel unless the main breaker is off. How is that technically different than just turning off the main breaker and plugging in a generator? How will that kill a lineman?
 

pistolpete1313

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An interlock is a $50 piece of sheetmetal that prevents turning on the breaker connecting the generator to the panel unless the main breaker is off. How is that technically different than just turning off the main breaker and plugging in a generator? How will that kill a lineman?
It's not different other than being idiot proof. It's for safety.

Power goes out, you fire up the generator but don't flip off the main breaker now all of a sudden your providing voltage up to the point where the limb broke the power line. Lineman assumes that power doesn't exist in both directions, but now it does. Zap

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alexb2000

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It's not different other than being idiot proof. It's for safety.

Power goes out, you fire up the generator but don't flip off the main breaker now all of a sudden your providing voltage up to the point where the limb broke the power line. Lineman assumes that power doesn't exist in both directions, but now it does. Zap

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So that's the question, if someone is mechanically inclined, has a small generator, no transfer switch or interlock, and finds themselves in a disaster situation as many people do every year...

Is it better for them to understand how to use the generator without endangering the linemen or should they just let their family freeze?

This is a DIY type forum so I would hope people would enumerate the dangers and help them. Maybe I just have too much faith in peoples abilities here.

Otherwise, why even have a forum, just a sticky?

Generator question.. call an electrician

Car problem... go to the dealer

Building question... hire a contractor

If you don't BAD things that are too horrible to even discuss will happen.

Done.
 
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volodar

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An interlock is a $50 piece of sheetmetal that prevents turning on the breaker connecting the generator to the panel unless the main breaker is off. How is that technically different than just turning off the main breaker and plugging in a generator? How will that kill a lineman?

Agree, turning off main breaker first is what I do as well. I also turn off the auxiliary panel with the 240v circuits (our generator is 3500w peak, 3000w run - don't want oven, hot water, clothes dryer in the circuit).

Our utility, via the web, tells us when power is restored - as well, we can see those nearby properties who we know do not have generators.

Our main breaker does not come back on unless our generator is off, and unplugged from the house.

How does that kill linemen?
 

Crazyjake8493

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So that's the question, if someone is mechanically inclined, has a small generator, no transfer switch or interlock, and finds themselves in a disaster situation as many people do every year...

Is it better for them to understand how to use the generator without endangering the linemen or should they just let their family freeze?

This is a DIY type forum so I would hope people would enumerate the dangers and help them. Maybe I just have too much faith in peoples abilities here.

Otherwise, why even have a forum, just a sticky?

Generator question.. call an electrician

Car problem... go to the dealer

Building question... hire a contractor

If you don't BAD things that are too horrible to even discuss will happen.

Done.

Just because you do something yourself, doesn't mean you shouldn't still do it right. $50 for an interlock is a small cost in relation to the generator itself. Even a proper cord to backfeed 120/240v costs at least $50.
 

wyliesdiesels

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Be aware that most lineman, when they see a house with gen power and discover no transfer switch or interlock, will cut the service at the pole and you wont be reconnected until a proper hookup method(ie interlock or transfer switch) is installed and verified by the AHJ.
 

alexb2000

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Just because you do something yourself, doesn't mean you shouldn't still do it right. $50 for an interlock is a small cost in relation to the generator itself. Even a proper cord to backfeed 120/240v costs at least $50.

I'm thinking about the person that runs down to HD or Lowes on the eve of a hurricane kind of scenario and wires up an extension cord with a dryer plug and hopes for the best.

Otherwise given preparation, planning, an electrician, etc. of course do the job right.
 

pistolpete1313

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Be aware that most lineman, when they see a house with gen power and discover no transfer switch or interlock, will cut the service at the pole and you wont be reconnected until a proper hookup method(ie interlock or transfer switch) is installed and verified by the AHJ.
What!?! They value their safety or something?

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Matt Matt

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A manual disconnect from power source to allow generator source cost what $30?

Yeah, on automatic disconnect with generator starter might cost you $500...

If your power is out for four days or one hour, don’t backfeed!
 

CJ7VFR

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Be aware that most lineman, when they see a house with gen power and discover no transfer switch or interlock, will cut the service at the pole and you wont be reconnected until a proper hookup method(ie interlock or transfer switch) is installed and verified by the AHJ.

A manual disconnect from power source to allow generator source cost what $30?

Yeah, on automatic disconnect with generator starter might cost you $500...

If your power is out for four days or one hour, don’t backfeed!

This actually happened to one of my neighbors back in 2012 during hurricane Sandy.

At the last minute he went out and bought a portable generator and rigged up a dead mans extension cord, which is one that has a 240v male plug on both ends. He ran the cord between the generator and the receptacle for his clothes dryer in order to back feed his load center for the house.

When the power went out during the hurricane he plugged in the cord and fired up the generator. During the rush to get power to the house, he forgot to turn off the main breaker in the panel. For the first few days it went ok, until the power company came around and found power being fed back up the pole.

So they went around to each house that had a generator running, and when they found his place did not have an approved method to back feed the house they actually cut his main line to the house up at the pole. Boom, done.

It took him almost 3 weeks to get the power company to hook it back up, besides the fine he received. And there was nothing he could do about it. He broke the law and he paid the price. It is against the law to back feed your home without some type of approved device that disconnects the main breaker in your load center from the incoming wiring from the pole.

In the end, he paid almost three times as much to get everything hooked back up than if he had just purchased either an Interlock or a manual transfer switch.

Jim
 
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Bretny

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You do realize that if he was back feeding the grid he would be powering the whole neighborhood. I very highly doubt his generator was capable of that. And if it was no one noticed that the power was back on for days and shut there generator off? I dont buy they cut his power.
 

alexb2000

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This is how it goes on these boards, I knew a guy, who knew a guy, who's brother in law had this happen. While I'm sure there are examples of stupid people doing just about anything under the sun if it were that pervasive and killing people they wouldn't be allowed to sell portable generators.

Also, I don't know about every location, but in Texas the linemen are not forcibly coming in your house to inspect your panel for an interlock and they are not going to punitively disconnect your power for weeks because someone could require power for a piece of medical equipment (O2 concentrator, CPAP, etc) and then the POCO could be liable for their death.

As an aside, there are a couple of "specialty" electricians running around this area that only do hot service change outs. They did a hot 400 amp. meter base install for me for $200, well worth it IMO. Point is there is a lot of hot work going on everyday, professionals expect it, and know how to deal with it.
 

Bretny

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Thats funny. They changed over my service hot too. I watched. It looked like they did it every day...must be a regional thing.
 

pjmariner

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This is how it goes on these boards, I knew a guy, who knew a guy, who's brother in law had this happen. While I'm sure there are examples of stupid people doing just about anything under the sun if it were that pervasive and killing people they wouldn't be allowed to sell portable generators.

Also, I don't know about every location, but in Texas the linemen are not forcibly coming in your house to inspect your panel for an interlock and they are not going to punitively disconnect your power for weeks because someone could require power for a piece of medical equipment (O2 concentrator, CPAP, etc) and then the POCO could be liable for their death.

As an aside, there are a couple of "specialty" electricians running around this area that only do hot service change outs. They did a hot 400 amp. meter base install for me for $200, well worth it IMO. Point is there is a lot of hot work going on everyday, professionals expect it, and know how to deal with it.

Stories aside, I think the main point is an interlock setup generally costs little more than making a dual male backfeed cable long enough to get from dryer to your generator, so why not do it right.

Last time we lost power I was going to make a back feed cable because like yourself I trust myself enough to use one. By the time I priced out the necessary cable and connectors at Lowes I was at over $120 bucks with 50' of cable so I could run cord out laundry, through garage and be 20' from house. Instead I sucked it up and used extension cords again. I then ordered an interlock kit for $60, a double pole 30amp breaker for $10, a 30amp inlet for outside house for $50, and a 25' generator cord for $45, I put inlet outside house just above fuse box so all I needed about 2 feet of 10-3 nm to get through wall in into panel.

So all in to do it right cost me $165 to do it myself vs $120 for something I was "safe" with, but would not anyone else to touch AKA my kids.
 

CJ7VFR

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You do realize that if he was back feeding the grid he would be powering the whole neighborhood. I very highly doubt his generator was capable of that. And if it was no one noticed that the power was back on for days and shut there generator off? I dont buy they cut his power.

Not back feeding the grid. He was back feeding his house, and because he never shut off the main breaker to his load center, the power company linesman were able to detect power being back fed up to the pole they were working on. As such, the linesmen needed to find out where the back fed power was coming from in order to work on the downed lines nearby, as well as protect themselves from some ****** illegally powering his home.

What happened in my neighbors case is that when the power company started to do the repair work to the lines on my street, they went around to anyone who had a generator running and asked to see how they were hooked up before they started work on the lines.

They wanted to see which ******* was back feeding their generators up to the pole for their own safety.

I have a portable generator with a 10 position manual transfer switch that I set up before hurricane Sandy, and mine was up and running when they came to my door. They said to me, not to a guy that knew a guy, who knew his uncle about the issue, but to me directly, to see my set up.

They said that someone who had a generator running in the area around the pole that had wires down was back feeding the line as they detected power coming back up to the pole. They wanted to see my generator setup, and make sure I was not the one illegally back feeding my house.

I showed them my set up, and they said I was fine, as the transfer switch was preventing any back feeding.

They then went across the street to my neighbors house, who had the illegal back feed hookup, with the double ended male cord (which by the way I saw with my own eyes when he made it) as his generator was also running.

I have no idea what they said to him, but a few minutes later his generator shut off, and one of the power guys went up the pole and cut the line to his house. Physically cut it at the pole. This I saw with my own eyes. They then did something to the line so that it did not fall to the ground, but was still hanging up at the location where it was cut.

They then went around to the 4 other houses that had generators running, but they never came back to the pole to cut any more lines, so I figure everyone else had a legal way of getting power to their homes via their portable generators.

Our area was hit very hard by hurricane Sandy, and there were lines down everywhere, and people everywhere powering their homes with portable generators. Because we all have wells and septic systems, everything we have requires electricity to run. If you did not have a portable generator for the 11 days it took to get the power back to our part of town, everything you had in your refrigerators went bad, you could not heat your home or have hot water, you only flush the toilet a few times, and you had no discharge for your human waste into your septic system.

Out here, the issue with people illegally back feeding a home is taken VERY seriously. And if you screw with the power company, which by the way is New Jersey Central Power and Light, they have no issues with cutting your power lines and making you pay a fine before they hook them back up.

Jim
 
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rlitman

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Not back feeding the grid. He was back feeding his house, and because he never shut off the main breaker to his load center, the power company linesman were able to detect power being back fed up to the pole they were working on....
I have no idea what they said to him, but a few minutes later his generator shut off, and one of the power guys went up the pole and cut the line to his house. Physically cut it at the pole. This I saw with my own eyes. They then did something to the line so that it did not fall to the ground, but was still hanging up at the location where it was cut...


Your first paragraph is a contradiction. By back feeding his house with the main on, he was back feeding the grid. How far that power actually traveled depends on where the grid is broken. If the trees took out the power downstream of your transformer, then he's just back feeding low voltage into a small group of houses (this is still a fire and electrocution risk). If not, then the transformer can easily convert the power he's back feeding into high voltage on the primary side (another fire and electrocution risk). As much as we all think that the load from this should always be enough to stall any portable generator, clearly it was not. Anyway, the biggest danger here (since linesman SHOULD all be smart enough to know how to handle the voltages on the wires) is the risk of the power being reconnected while his back-feed was still connected. That would almost certainly end badly.

In any case, what your neighbor did was dangerous, and I can certainly understand why the power company would be all upset about it.

As for what they cut, if they just left the neutral intact, the wires wouldn't fall.

Certainly, it is unlikely that cutting your lines is company policy. Still, while pulling the meter should suffice, if this guy already back-fed the grid, what's to say he won't plug his meter back in, so disconnecting it at the pole is the logical thing to do. However, since the power company owns the overhead lines, I'd expect them to just disconnect them (it just takes loosening one bolt) rather than cut them.

Anyway, when you do stupid things like this, you can expect similarly stupid repercussions.

main-qimg-50636b8f7c0ef220b270ca823490494b
 

CJ7VFR

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Your first paragraph is a contradiction. By back feeding his house with the main on, he was back feeding the grid. How far that power actually traveled depends on where the grid is broken. If the trees took out the power downstream of your transformer, then he's just back feeding low voltage into a small group of houses (this is still a fire and electrocution risk)...

That is what I meant. The power he was putting up the pole was not enough to send any usable power to any of the homes near by, but enough to let the linesmen know someone was illegally back feeding their house.

As I am across the street from this neighbor, none of his power feeding the pole was enough to reach my house and power things like the clocks on my appliances that were still hooked up to the utility power, and waiting for the lines to get fixed and power restored. So in my case, I would not have known he, or anyone else was back feeding illegally. I only knew because my neighbor told me he was going to do it.

I always wondered how much actual power a 5000w generator, back feeding a pole, would be putting out to all the other houses, and how far down the line a linesman could detect it.

Jim
 

CJ7VFR

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...I'd expect them to just disconnect them (it just takes loosening one bolt) rather than cut them.

I think this is what they actually did, as they did something to the line to keep it up at the pole instead of letting it drop down to the ground. His line was clearly no longer connected to the pole up near the transformer.

Jim
 

Bretny

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Mabe that transformer has diodes in it. I highly doubt it though. No one would beable to sell back solar and the lines man wouldnt beable to detect the voltage coming back. Also you would beable to see voltage at your house if he was backfeeding with the main on and you didnt. Unless he was running his mouth to the wrong people i would put this in the fiction category.
 

yeldogt

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There must be some way that this back feeding can occur w/o overloading the portable generator ... We had insert included with our bill a few years ago.

In an emergency I can see how someone could put together a system to save his house -- but, after understanding the issues doing it incorrectly again is just foolish.

We have had this debate before -- At my rural place in PA we need to have an actual switch/panel setup vs just the interlock on the panel. It's still not an overly expensive setup -- I'm sure even with a fair about of wire it's under $300 dollars for parts.

They also make a gizmo that mounts between the meter and the meter pan -- It's basically a self contained auto transfer switch with a plug on the bottom. It's not cheap at $650 -- but, I'm wondering what's really involved as far as codes and inspection. It's remove meter -- install and place meter back on.
 

alexb2000

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There must be some way that this back feeding can occur w/o overloading the portable generator ... We had insert included with our bill a few years ago.

In an emergency I can see how someone could put together a system to save his house -- but, after understanding the issues doing it incorrectly again is just foolish.

We have had this debate before -- At my rural place in PA we need to have an actual switch/panel setup vs just the interlock on the panel. It's still not an overly expensive setup -- I'm sure even with a fair about of wire it's under $300 dollars for parts.

They also make a gizmo that mounts between the meter and the meter pan -- It's basically a self contained auto transfer switch with a plug on the bottom. It's not cheap at $650 -- but, I'm wondering what's really involved as far as codes and inspection. It's remove meter -- install and place meter back on.

I see generators as two types, fully automatic, your gone, power goes out, generator starts and runs. Cadillac solution.

Or, some form of manual switch requiring you to be there to set it up. Of those options, with no Interlock allowed, I would just do a manual throw switch like this because it's idiot proof, even more so than an interlock:

https://www.ebay.com/itm/Eaton-Doub...=item41f472ab5d:g:BPQAAOSwLF1YAY37:rk:10:pf:0

However, I don't think it will be cheap, I would say ~$1200 in parts and labor since you have to put any switch between the meter base and the main, fabricate an extension cord, have a place to plug in the gen, etc.

Those meter adapters look kind of questionable to me and I don't know how the utility would like them either.
 
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