Transfer Switch - with Pics

[crokett]

Here is the switch and panel:


Here is the switch:


The red bar in the middle is a lockout. The line switches are on the right, generator switches on the left. To switch to gen power I turn the line switches off, move the lockout to generator position then turn the gen switches on. There are two power meters on the left to let me know approx how much power I am pulling. When the drywall is done and painted I will trim out both the switch and the sub panel.

The transfer switch works by having the line or house side of the switch hooked to the breaker in the sub. The load to the house is then hooked to the gen side in the switch. This is all done in-line.

There are some folks who simply wire an extra 220 outlet into their house then just turn off the main and all the circuits they don't want powered. My dad does this but he knows what he is doing. I could have done it this way but just in case somebody else (like my wife) has to hook this up I wanted it to be as simple as possible.

[leehljp]

I have been thinking about this for when I get back to the States for retirement. I hope I don't lose this link. Thanks!

[LinuxRandal]

I have one minor suggestion.

Put an emergency light, over by it if it isn't automatic. This will help keep you from fumbling around when you need to switch to it.

[LCHIEN]

There are some folks who simply wire an extra 220 outlet into their house then just turn off the main and all the circuits they don't want powered. My dad does this but he knows what he is doing. I could have done it this way but just in case somebody else (like my wife) has to hook this up I wanted it to be as simple as possible.

That's illegal in most places. Its easy to make a mistake and connect your genset to the incoming power line. If the incoming power is on your generator will likely be toast. Worse, if the incoming power line was off due to power tranmssion failure, the lines would be made live back to the break, including any tansformers would step the voltage back up to thousands of volts. and kill some unsuspecting lineman who turned off all their switches and breakers going back to the power plant...

[cabinetman]

That's illegal in most places. Its easy to make a mistake and connect your genset to the incoming power line. If the incoming power is on your generator will likely be toast. Worse, if the incoming power line was off due to power tranmssion failure, the lines would be made live back to the break, including any tansformers would step the voltage back up to thousands of volts. and kill some unsuspecting lineman who turned off all their switches and breakers going back to the power plant...

Hey Loring...ya think I'd see the mushroom cloud blast from Ft. Lauderdale?
.

[jackellis]

That's illegal in most places. Its easy to make a mistake and connect your genset to the incoming power line. If the incoming power is on your generator will likely be toast. Worse, if the incoming power line was off due to power tranmssion failure, the lines would be made live back to the break, including any tansformers would step the voltage back up to thousands of volts. and kill some unsuspecting lineman who turned off all their switches and breakers going back to the power plant...

Not to mention you could be the target of an ugly lawsuit. I don't necessarily agree with all the crap utilities put in their rules, but electricity is pretty unforgiving and properly installed protective devices are required for good reason.

[rnelson0]

That's illegal in most places

I am not understanding why. If the main is turned off, how is current getting upstream?

That is not to say that it is the best idea. It is very easy to have the generator on when the power comes back in through the main, causing "issues"

[cgallery]

I am not understanding why. If the main is turned off, how is current getting upstream?

That is not to say that it is the best idea. It is very easy to have the generator on when the power comes back in through the main, causing "issues"

Because you can accidentally forget to disengage the main. So you are powering your house and the lines to the break.

My drafting instructor told me of a lineman he meet that had a real high pitched voice. He was repairing a downed power line. He tested everything before he started and it was all dead. As he was working, someone engaged a backup generator, and it nearly killed him.

A remaining side-effect was his permanently high-pitched voice.

[GoFish104]

It is very easy to have the generator on when the power comes back in through the main, causing "issues"
It's even easier to forget to disconnect when you fire up the generator. The power will backfeed thru the transformer which steps it up to 'system voltage' 7200 or 14400 volts on the systems I work w/. An energized line looks absolutely no different the a dead one. If I was to know someone was backfeeding a line I was working on I would do everything in my power to energize that circuit just because I would want to blow that generator up. Then I would cut their service down & inform the person they needed an electrical engineer to design a new service. And that it might take months before all the paperwork cleared. Yeah the power companies have some assine rules mostly cause most of us know someone that was injured or killed because someone did something stupid. OK rant over. Jack

[LCHIEN]

There are some folks who simply wire an extra 220 outlet into their house then just turn off the main and all the circuits they don't want powered. My dad does this but he knows what he is doing.

this was the remark that started it.
While his dad may know what he is doing, it physically allows a condition which is unsafe.
1. he may accidentally turn on ht main breaker in a moment of forgetfullness (and we all have those).
2. If he is not present to guard the equipment a well-meaning person may walk by and flip on the main breaker assuming that's why the power is out. At the same moment the dad is out back changing the oil in the generator just before he restarts it.
There are any number of scenarios that have the mains breaker being closed by someone who does not know (closed is the normal position) and the generator being on or coming on shortly afterwards.

The transfer switch is a positive safety device... by having break before make double throw switches it guarantees that the mains power and generator power cannot be cross-connected even by accident.

[crokett]

this was the remark that started it.
While his dad may know what he is doing, it physically allows a condition which is unsafe.
1. he may accidentally turn on ht main breaker in a moment of forgetfullness (and we all have those).
2. If he is not present to guard the equipment a well-meaning person may walk by and flip on the main breaker assuming that's why the power is out. At the same moment the dad is out back changing the oil in the generator just before he restarts it.
There are any number of scenarios that have the mains breaker being closed by someone who does not know (closed is the normal position) and the generator being on or coming on shortly afterwards.

The transfer switch is a positive safety device... by having make before break double throw switches it guarantees that the mains power and generator power cannot be cross-connected even by accident.

Loring, I know all this, that was why I went with the transfer switch. I am trying to get my dad to rethink things. That said, plugging your generator into a 220V circuit is more common (at least around here) than you might think. Most folks I know just use the dryer circuit. The other reason I have the switch is my generator is not big enough to power the entire house and I'd have to turn off a lot of breakers. This way I only have to worry about 5.

The emergency light suggestion is a good one and I will think about it but I figure that is what a flashlight is for.

[BobSch]

I figure that is what a flashlight is for.


As long as you keep fresh batteries next to the switch!

[Mr__Bill]

The emergency light suggestion is a good one and I will think about it but I figure that is what a flashlight is for.

I'm wondering what is powering this emergency light when the power is out?


Bill, who is a great believer in Colman Lanterns.

[LinuxRandal]

If you go into commercial buildings you will see emergency lights. They are designed to light towards the exits in case of a power outage. Internally they have a battery that they switch to when power goes out. They ONLY light from the battery. So if power came back on, while he was down there switching stuff, he would know it right away, as well as providing the light to see the switches.

[crokett]

I'm wondering what is powering this emergency light when the power is out?

What LinuxRandal said. The coleman lantern suggestion is a good one also, except I'm not sure I want something on fire like that in my house either. A woodstove is different - you can't knock it over and break the glass on it. A flashlight is much safer. I could just be paranoid, but with 2 young kids...