Transfer Switch question

[mendozer]

So I'm going to be installing an interlock switch kit (OEM for my panel) here soon. The PO for my home had a Gentran switch. 6 circuits each with 15 amp breakers. When I was searching through my main panel I found that three of them went no where. What I mean by that is the Red or Black wires from the switch went into the panel to a breaker that wasn't labeled nor had any other wires going into it. Maybe I don't understand specifics on transfer switches, but it has a "Line" "off" and "Gen" rocker switch, indicating to me the switch is there to transfer voltage from different sources. So shouldn't the breakers in the main have two wires running to it?

Or was this the old school way of backfeeding a panel, just hooking up several 15 amp breakers to power the bus bars?

I'm ripping it out to simplify things when I have power outages, I just don't know what to do with those breakers

 

[Zeke]

Sounds like it was illegally backfed. Why more than 2, I couldn't even begin to guess. And the way the typical TS is wired is only one source of power can enter a panel at a time. I have a subpanel in which the feed that goes from the main panel breaker to the sub goes to the TS instead and the gen power is on the other side of that switch.

 

[mendozer]

Interesting. Well the current setup is to only allow one supply at a time too, but it doesn't seem to link up like your picture. It's hard to see there, but the yellow dot is the breaker that worked. Nothing else worked during the power outage on this thing.

 

[CJ7VFR]

Most of those transfer switches get hooked up the same way. There is normally one red wire and one black wire for each circuit coming from the transfer switch. These wires will have markings on them that correspond to the circuit and toggle switch on the transfer switch. Example, transfer switch circuit labeled "A" will have the letter "A" marked on the red and black wires.

After shutting off the power to your homes breaker panel, you disconnect the power wire (normally black) from the breaker in your house panel that you want to power with the generator.

Then you connect the red wire from one of the circuits in the transfer switch to the breaker in the house panel.

Then you connect the power wire you disconnected from the breaker in the house panel to the black wire from the circuit in the transfer switch. You normally do this with a wire nut.

You do this for all the circuits in the transfer switch. Also, the transfer switch will come with a single ground wire for the entire unit that you also have to hook up to the house panel ground bar. And it should also have a single white wire that you have to hook up to the house panels neutral bar.

I have a similar transfer switch installed on my house panel. Here is a figure from the instructions that shows how things get hooked up. They also show a 240V double pole breaker set up that you can do as well.

I can see several wire nuts inside your panel. Are these hooked up to wires coming from the transfer switch?

Jim

 

[mendozer]

Ah ok that makes more sense. Thanks for that explaination. There are wire nuts in there labeled A through E. Some didn't make sense but now that I understand more, I would look for different things. Only one circuit worked anyways so maybe it wasn't hooked up well. Also I don't like being stuck on a few circuits only so either way the interlock seems like the way to go for me

 

[Zeke]

CJ, that looks like it will work but there's no lock out for the main. I doubt it's acceptable.

 

[dave*99]

CJ, that looks like it will work but there's no lock out for the main. I doubt it's acceptable.

There is no need to lock out the main when using this type of transfer switch. Each of the branch circuits that are connected to the transfer switch (typically 6 circuits) are individually disconnected from the bus (actually the branch circuit breakers) in the main panel via the transfer switch. Therefore there is no need to lock out the main.

 

[CJ7VFR]

CJ, that looks like it will work but there's no lock out for the main. I doubt it's acceptable.

As dave*99 said, an actual Transfer Switch does not lock out the main breaker. It requires no touching of the electrical panel once it is installed. And in many municipalities, it is the only acceptable and legal way to backfeed your homes electrical panel. Some places do not allow Interlock systems.

The breakers you want to have powered by your generator are controlled by transfer switch via the 20 amp rated toggle switches. The toggle switches have three positions on them. One position is for generator power, one position is for utility power and one position, which is in the middle, is no power.

This guarantees that at no time can both generator power and utility power be sent to the same breaker in your homes electrical panel.

I installed my transfer switch, which is a 10 circuit version, because my wife is deathly afraid of the electrical panel in our house. Even though she knows how to get the generator out and hook it up, she said she would never go into the electrical panel and shut off all the breakers, and then start turning some back on, like you have to do with an Interlock.

With the transfer switch, she just flips the toggle switches from Utility to Generator, and our vital circuits are up and running.

Jim

 

[Zeke]

I don't like it. The possibility exists that the house can be powered simultaneously by utility power and home brewed power.

 

[iced98lx]

Breakers hooked to the transfer switch will only ever be fed by one or the other. You're picking several breakers and putting a switch in between the circuit and the breaker, the switch determines if it's going to go back to the panel and get fed from mains or go to the genny and get fed that way- one way or the other never both. There is no way the genny powers the mains.

 

[mendozer]

So after understanding all of this, I gather those breakers that are unlabeled do something, I just don't know what yet. I'll have to just assume they're useful for now and put the black wires back on.

 

[dave*99]

I don't like it. The possibility exists that the house can be powered simultaneously by utility power and home brewed power.

In a sense you are correct and it happens like this - during a power outage the homeowner fires up the genny. Then flips a few breakers in the transfer switch over to the genny side. So his refrigerator and heater and some lights run.

At some point the POCO restores power. And all those circuits that were NOT routed through the transfer switch come alive. The lights in the spare bedroom work again.

At this point, some of the house is running off the POCO and some off the genny. But there is no interconnection between those two sets of circuits.

Safe? Absolutely.
Done all the time? Yes.
Most common way to add a portable generator to your house - Yup.
Code approved method - yes in most jurisdictions.

But if you don't like it, just don't install it in your house. The OP will be just fine.

 

[CJ7VFR]

I don't like it. The possibility exists that the house can be powered simultaneously by utility power and home brewed power.

Read dave*99 response. It is right on the money. A transfer switch is not "home brewed" power. It is an NEC code compliant way to get generator power to your home safely and to guarantee you are not sending generator power back up to the pole/line where it can injure a linesman.

If you look at the picture you posted, the toggle switches on the transfer switch work the same way as what you have shown. For powering specific breakers in your homes panel, either the utility power or the generator power is allowed to pass thru the transfer switch. Instead of just one single large switch that you have shown, there are 6, 8 or 10 toggle switches, one for each individual breaker.

There are many threads and posts from the sparkies on this forum about using transfer switches, and how they are one of only several legal and code compliant ways to backfeed your home.

Jim

 

[CJ7VFR]

So after understanding all of this, I gather those breakers that are unlabeled do something, I just don't know what yet. I'll have to just assume they're useful for now and put the black wires back on.

Yeah, that seems to be a good place to start.

If you are removing the transfer switch with the intention of eventually installing an Interlock, making sure all the house wires are connected to the proper breakers in your house panel is the right move.

It will be interesting to see if after doing that, and putting the house panel back to it's original set up, will show you where/what those breakers were hooked up to.

Jim

 

[Zeke]

Yes, yes, I understand. What might have helped is a diagram of the TS showing that it too has individual breakers for the pump and fridge shown in the diagram above. And I misstated about lock-outs.

I have a transfer switch that is a 60A that powers the sub panel I put in the house when I removed all the K and T, rewired the whole shebang, and installed AFIC's as well as any missing GFCI's needed. One throw moves the power source. All heavy draw stuff is not in that panel.

OK, and I understand the one wife's fear of the main panel when she can flip some individual breakers in a convenient location. I think that's a lot of work rewiring those circuits to a 'convenient' panel if the main load center isn't inside or in the basement (which we don't have many of in SoCal).

And I know I have to do 2 steps if not 3 to turn off the breakers in the sub, light up the gen and then flip the critical breakers on one by one.

So maybe it is better. You say potatoe and I say potato.

Oh, and by 'home brewed', I simply was being un-clever saying generator power was local to the home rather than central. "Home Brewed."

 

[imjustdave]

Honestly if you have a decent size genny I would pull that out and just install an interlock with the main, and feed the entire panel. with proper load management you can usually run just about anything within the limits of the generator. My last home had this and I loved it, even ran the hot tub once at midnight on christmas eve, we were literally walking to the tub when the power went out... I continued walking around the corner and fired up the genny, walked back into the hose to the panel and flip, flip... I did shut down the heat pump too flip.... Then jumped into the tub with the wiffy, jets and all 12,500 watts will run a bunch 1 at a time.

 

[mendozer]

Honestly if you have a decent size genny I would pull that out and just install an interlock with the main, and feed the entire panel. with proper load management you can usually run just about anything within the limits of the generator. My last home had this and I loved it, even ran the hot tub once at midnight on christmas eve, we were literally walking to the tub when the power went out... I continued walking around the corner and fired up the genny, walked back into the hose to the panel and flip, flip... I did shut down the heat pump too flip.... Then jumped into the tub with the wiffy, jets and all 12,500 watts will run a bunch 1 at a time.

I am doing an interlock. I just wanted to know how to properly restore the other wires after removal of the switch

 

[LS6 Tommy]

I don't like it. The possibility exists that the house can be powered simultaneously by utility power and home brewed power.

No it can't. The transfer switch circuits are all switched manually between "Service" and "Generator". They can't be fed from both sources simultaneously. All the other circuits are only fed from "Service".

Tommy