# Transfer switches



## dirtman (Sep 15, 2011)

a four and a half day power outage has motivated me to get serious about my electricity. I have a 6500 running 8000 surge watt generator that I use for work. I was pricing transfer switches and they seem a little steeply priced for my budget. I am wondering why I can't just wire a regular square D sub panel into the circuits I need and just shut off the main from the meter when I want to run the generator. That would cost about a third of what the 30 amp transfer switch I was looking at costs plus that would be a 60 amp main breaker which is admittedly more than my generator needs plus I have alot of extra square d breakers I've picked up from jobs I've done. Where am I thinking wrong about this?


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## Harry Chickpea (Dec 19, 2008)

Electric code is written to protect everybody- but especially the people who have no clue about electricity. If your house is insured and you had a problem, you be scrawwed.

That said, I've just flipped the main, the disconnect on the trailer pole, and used a Jesus cord. DW won't fool with it, and no kids around to worry about. The far bigger issues are generator noise and fumes. That noise will wear you out if you have to listen to it all the time.


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## Jim-mi (May 15, 2002)

Yes they seem pricy . .but if wired in properly, the safety factor makes them well worth it........ 

Not sure what a "Jesus" cord is ,. . . but if it is a double male plug deal, those are asking for trouble . . . . A flip of the switch at the wrong time can cost you far more than a transfer switch.
(Thats after you put the fire out)..........


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## farminghandyman (Mar 4, 2005)

you could check in a what is called a inter lock kit

http://www.interlockkit.com/

I think there is a couple of companys that make them, 

I would check with you electrical inspector before buying, they say it meets all NEC requirments, but some areas are not thrilled with them,


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## Bearfootfarm (Jul 13, 2006)

> Not sure what a "Jesus" cord is ,.


It has male plugs on each end
You plug into the generator, and then into a house outlet to backfeed current.

It's NOT a good way to do things


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## Harry Chickpea (Dec 19, 2008)

I'll totally agree that for many (if not most) people a Jesus cord is not the way to go. However, electricity doesn't give a rodent's hiney whether it goes through a transfer switch or Jesus cord. I've also done the generally approved extension cords in the house routine during power failures and found those cords to present much more of a danger than a backfeed through an otherwise unused circuit.

Notice however that I specified - NO kids or others who would interfere - TWO disconnects to the power main - and more than a passing knowledge about electricity.

My reason for bringing it up was that if someone is going to spend money trying to rig up something that is already not to code, will void any homeowner insurance, create re-sale issues, and inherently dangerous, then the simple cord will do the same job.


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## Jim-mi (May 15, 2002)

Harry you are correct in that there is a darn Small percentage of folks who know much about electricity and its potential dangers.

I take the general stance "Hire a good electrician" because I have No idea of the ability of the people on the other end of the 'question'

Yes . ."NO Kids or others" . . . . Big problems waiting to happen . . . . . .

A friend of mine is the first "Inspector" on an all volunteer small village fire dept. . . . . .he ain't no backwoods hick . . . and should questions arise he will quickly call the state inspector . . . . . 
They are heavy on looking at the wiring, receptacles, etc.. So an electrical caused fire from 'funny' wiring would negate insurance in a big hurry.


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## dirtman (Sep 15, 2011)

Aside from the other considerations, I'd still like to find out what the difference is between a store bought transfer switch and a home made one. If I installed a regular sub panel and wired its breakers into the main panels breakers for the well pump and kitchen circuit for the refridgerator and a few lights and wired it to the generator then as long as the sub panel main was shut off so I didn't feed power from the utility back into the generator and as long as the Main to the main panel was off when the generator was in use what does a manual transfer switch do that is different?


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## ace admirer (Oct 5, 2005)

if the ASSEMBLY is not ul approved, its illegal and will void insurance.

kinda like the weather, you can talk about it, but you can't do anything about it..

there has to be a fool proofed way of shutting off utility power before it is possible to turn on supply from local sources (generator). mechanical interlocked.

if you are going to rig something , why not use 20 amp three way switches after your normal power distribution panel to form circuits that can be fed from either panel or generator.


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## Harry Chickpea (Dec 19, 2008)

Ace aced it. There is no such thing as a "homemade" transfer switch that will pass.

The concept itself is quite simple. It forms a non-shorting double pole double throw switch like this:










When the electric sources are wired to the outside terminals, and the panel to the center terminals, there is no way that there can be an accidental connection between electric sources.


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## Jim-mi (May 15, 2002)

Chuckle . . .Harry I have a Big three pole knife switch like you show. . . . . .
I'm thinking of using it........................nuff said


dirtman you might get away with it, but you will have a specific sequence of flipping breakers . . . . . . .And if you or someone else does it wrong . . disaster.

The switches MUST be "break before make"...................


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## Harry Chickpea (Dec 19, 2008)

I happened to run across a HUGE one in an old theatre once. Pretty standard looking cut-off box, but big. Inside, it did the double throw thing. 600 amp at least. I have no idea why it was put in, since one side was dead.


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## dirtman (Sep 15, 2011)

I surrender. I will buy an approved transfer switch but I think they are a big rip. Three hundred dollars for a box you can duplicate for less than a third of the price to use a $700 dollar generator. It sticks in my craw.


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## Harry Chickpea (Dec 19, 2008)

Three hundred isn't too bad in comparison. Our 400 amp meter box cost $800 for the box and two 200 amp sets of breakers.


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## solidwoods (Dec 23, 2005)

dirtman said:


> I surrender. I will buy an approved transfer switch but I think they are a big rip. Three hundred dollars for a box you can duplicate for less than a third of the price to use a $700 dollar generator. It sticks in my craw.


You don't have to surrender- there was never a war.

If you think its a big rip and the "you" can build one for less than a third then do it big guy. No really do it, do it yourself.
You get what you pay for and you don't want to admit that for a device like this both electric generation devices can't be energized at the same time and shouldnt be set up so they can.
Your fighting yourself. 
jim


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## solidwoods (Dec 23, 2005)

Dirtman.
Here's one for you
Local Sales Network - transfer switch in Sparta, TN #2681575 - Go LSN!


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## JohnP (Sep 1, 2010)

If you're only doing limited, isolated circuits then you might look into transfer switches for RVs. They're UL listed, though not for stationary buildings. Only RVs/travel trailers. You can get a wfco t30 (30 amp) for 50 bucks, 50 amp switches are 150-200 bucks.


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## nadja (May 22, 2011)

Transfer switches are designed to protect both you and the lineman who may be working where you can't see him. If he goes up the pole and doesn't know your little gennie is running, expecting dead lines, you can actually electrocute him when he grabs said dead line. Also, if the power comes back on while your gennie is running , it can also in an instant, burn your house down, and possibly others as well. 

Do NOT ever use a Jesus cord or anything like that. 

A legal transfer switch will prevent those types of accidents from happening, as you can never have more then one power source coming in to the same place at the same time. It is like two trains coming from opposite directions on the same track at about 2,000 miles another. Not good


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## Ozarka (Apr 15, 2007)

Square D makes an accessory for their 200 Amp combo meter/panels that consists of a different panel cover with mechanical interlocks so you have to turn off the main before you can turn on the breaker between the panel and your genset. The gizmo is about $ 100 and is the simplest method of effecting a safe transfer. Any Sq D distributor can get it for you if they don't stock it. I am going to use one on my own service when I switch from overhead to underground.

O,btw, a bit of trivia: The portable generators are required to be equipped with a "spark arrestor" and not a muffler....that's why they be so loud.....

Had a client's helpful BIL come up to his place during the great ice storm in N. Ark. in 2010 and deduce that since the client had a ventless propane fireplace that the fumes from a propane generator would be ok.......so he ducted the generator exhaust into the crawl space to help heat the 4,000 sq. ft. home and almost killed 7 people...all are OK, except his heart condition was pushed to the critical zone and he really has not recovered from the near-disaster.....


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## Harry Chickpea (Dec 19, 2008)

nadja said:


> Transfer switches are designed to protect both you and the lineman who may be working where you can't see him. If he goes up the pole and doesn't know your little gennie is running, expecting dead lines, you can actually electrocute him when he grabs said dead line. Also, if the power comes back on while your gennie is running , it can also in an instant, burn your house down, and possibly others as well.
> 
> Do NOT ever use a Jesus cord or anything like that.
> 
> A legal transfer switch will prevent those types of accidents from happening, as you can never have more then one power source coming in to the same place at the same time. It is like two trains coming from opposite directions on the same track at about 2,000 miles another. Not good


Crock. TOTAL crock. Neon John once exposed it in a particularly colorful way:

Ah, the heroic lineman slaving away against all odds, natural and
manmade, to save humanity. Spare me. You're not talking to a lowly
"civilian". I'm someone who's been right there on the hooks and in
the bucket just like you (if you're not a complete poseur.)

Let's examine your statement a bit. Of the following things, which do
you suppose presents the most threat:

1 A live line falling on you while you work.
2 The wrong breaker back at the sub being opened for the job
3 Someone, say, a supervisor, violating the tag-out order and closing
in a breaker on a line under repair.
4 The wrong breaker being closed, hotting up the line under repair.
5 Induction from adjacent lines making the "dead" line hot.
6 Static, lightning, switching surges, etc, making the "dead" line
hot.
(any number of other incidents)
100,000 Someone backfeeding from a generator making the "dead" line
hot.

Hint: I put them in approximately the order that I perceive the risk
to be. I've personally experienced items 1-3. Only result in each
case was the grounding line jumping from the fault current and
(sometimes) a flash off in the distance.

If you have any training at all (and didn't just show up one day to
start twisting wires together) then you know that ALL conductors are
considered hot and that you wear your hot gloves and your jacket and
insulating hardhat all the time. And that you gut and blanket any
nearby conductors - dead or alive. And that you lay grounds BEFORE
you do anything else to work on a "dead" line.

Neon John could be a pain sometimes, but he pegged this one completely. He had other threads on it where he was less nice.

Full thread here:
Generator transfer switches (John De Armond)

Seriously, pull the thread up and read John's remarks. I have rarely seen a usenet poster do a slam-dunk putdown of someone talking out their *ss as his one in this thread. It wouldn't have worked, except everything he was saying was dead on accurate. <OUCH>


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## Jim-mi (May 15, 2002)

Interesting long read . . . .

Yup . .Rule number One; run grounds


It is still a fact, and will be so forever, the vast majority of folks know nothing about electrical stuff . . . . . .Other than "Here is the wall switch that I turn on and off".....

Then of course there is the middle ground of "know enough to get in trouble quickly"

So when in dought I would say Hire an electrician . . . . the @ss you save may well be your own.............


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## InvalidID (Feb 18, 2011)

Jim-mi said:


> Interesting long read . . . .
> 
> Yup . .Rule number One; run grounds
> 
> ...


 That's me exactly! LOL


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## dirtman (Sep 15, 2011)

Ozarka said:


> Square D makes an accessory for their 200 Amp combo meter/panels that consists of a different panel cover with mechanical interlocks so you have to turn off the main before you can turn on the breaker between the panel and your genset. The gizmo is about $ 100 and is the simplest method of effecting a safe transfer. Any Sq D distributor can get it for you if they don't stock it. I am going to use one on my own service when I switch from overhead to underground.
> 
> O,btw, a bit of trivia: The portable generators are required to be equipped with a "spark arrestor" and not a muffler....that's why they be so loud.....
> 
> Had a client's helpful BIL come up to his place during the great ice storm in N. Ark. in 2010 and deduce that since the client had a ventless propane fireplace that the fumes from a propane generator would be ok.......so he ducted the generator exhaust into the crawl space to help heat the 4,000 sq. ft. home and almost killed 7 people...all are OK, except his heart condition was pushed to the critical zone and he really has not recovered from the near-disaster.....


This sounds like a plan. I do have a 200 amp square D panel. I asked the guy at home depot but that was useless. I'll try a electrical supply company next time I get to town.


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## farminghandyman (Mar 4, 2005)

there are extension cords, for emergency use, it may be a cheaper and better for many if your power outages are not often,


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## farminghandyman (Mar 4, 2005)

> Square D makes an accessory for their 200 Amp combo meter/panels that consists of a different panel cover with mechanical interlocks so you have to turn off the main before you can turn on the breaker between the panel and your genset. The gizmo is about $ 100 and is the simplest method of effecting a safe transfer. Any Sq D distributor can get it for you if they don't stock it.





> you could check in a what is called a inter lock kit
> 
> Generator InterLock Kit
> 
> I think there is a couple of companies that make them,


these are fairly cost effective as well,


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