Power transfer switch for homes.

[Kenfranklinl]

I have the same unit mrmicky has and it has worked out great. Where I live I
lose power a couple times a year and the year before last we lost it for two weeks. I don't remember the install cost because I was adding on a garage at the same time. I know it did not take the electrician very long to install.

I made a dog house for my generator attached to the back if the house. What I also had installed was battery emergency lights so when the power goes out at night I have a light on at the Generator, the cellar and one at the power panel so I'm not carring a light while starting the generator and switching over the power.

 

[tommu56]

My switch came with the transformer. It has three position ON, OFF and Axiliary power.

That set up is definitely not the norm around here.


tsteahr

I do prefer these too if its a new install it is Cadillac all the way!

tom

 

[tsteahr]

What did this 200 amp manual transfer switch cost installed?

I mounted the switch on the wall, installed the generator outlet and ran the wire and conduit from the generator outlet to the switch myself. The meter needed to be pulled (which requires a permit and informing the utility company) to complete the installation so I hired an electrician to do all the work with the heavy 0000 wire that goes from the meter to the switch and from the switch to the main breaker panel. That aluminum wire is difficult to get through conduit. I needed a longer run of wire coming from the meter box. This meant working in the meter box in close proximity to the live feeds coming from the utility pole. I was not comfortable working with the heavy wire and wrenches only inches from a nearly unlimited current source. One slip of the wrench and toast :shocked:.

In total I probably spent $1300-1400 for all the materials and 5 hours electrician labor. But time and material required will be different for every install. Mine was a little more involved that average because of switch placement issues. I probably saved 4 hours labor installing the generator plug, conduit, wire and mounting the switch myself.

 

[Briar Hill Brittanys]

We installed a 20K Seimens with SE rated automatic transfer switch. Power goes off, 30 seconds later unit starts and stabilizes. Transfer switches to generator in about 45 seconds after power loss. Transfer to grid power takes place when it returns, generator then runs in cool down mode and shuts down. All of this takes place automatically. The unit tests and exercises weekly. It runs on propane, and can run at full load for about 10 days on a 500 gal. tank. Before we had this unit installed, we experienced weather related power outages for a total of 16 days. Mostly ice storms in 07 and 08, and severe t-storms in May of 08. Installed the generator and transfer switch in late summer of 08. Our home is 1800 sf, total electric, heated with wood. To date it's run problem free, maintenance is simple. Highly recommend and happy with the quality. Only thing I'd do different is get a liquid cooled unit that runs at lower rpm. The transfer switch itself is a fairly straight forward installation. Installs between the meter base and main panel. It did require power company to come out and de-energize power at the transformer while installing, and re-energize at completion.

 

[cycle_gator]

I guess I'm a little old school. I looked at those interlock plates that you screw onto your breaker panel cover plate and then backfeed the panel through a 220 breaker. I know they meet Code in most areas. I also talked to three different electricians about those plates. The two younger ones said they work great and I'd be foolish to waste my money on a proper whole house transfer switch. The older, more experienced electrician (a personal friend who has retired) agreed they meet Code, but he would never install one. He has seen too many things happen to trust isolation to a breaker in the panel. There is no way to know what can happen to the utility system during a severe storm. Utility lines can get shorted, voltage can go way high momentarily (say a transformer switchyard has a problem) or the neutral leg can get energized.

In other words, things can happen outside the home that a 220 breaker mounted in the panel is not designed to handle. A interlock plate is designed to protect the utility lineman working to restore power. It is not designed to protect your house.

I believe a separate transfer switch panel provides superior isolation between the house and the utility. Throw that switch and I don't care what happens with the utility lines. I'm isolated.

So I did it the old fashioned way, 200 amp manual transfer switch. People have told me I wasted my money. I'm ok with that.

Total Isolation is a bit more complicated than that. I think you will find there remains an electrical path through the grounding system and likely the neutral, in your transfer switch. Don't get me wrong, it is a nice set up, but the only way to develop total isloation is completely separated circuits. The aux. or generator circuits would only operate off the gen set and have totally separate wiring including a different ground. This is the only way to be completely isolated from the utility.

 

[crazyal]

Amazing how folks just love to spend money cause they don't have a clue. Barnum & Bailey said it best.

Notice the schematic from the site for Generator Interlock that Tommu56 posted ........... looks almost exactly as I described.

That's how I do it. I'm sure it's not the best way but it works fine for me and no laws here saying you can't. I do have an inductive light on the feed coming in from the line so I know when the power has been restored.

With three different buildings to feed power to and a meter that's 300 yards from the house if I wanted to use a transfer switch I would need to make a pad and install a standby genset.

 

[TripleR]

I paid an electrician $400 to put mine in. I have used the back feed and my brothers still do, but it made me too uncomfortable.

 

[rjkobbeman]

Amazing how folks just love to spend money cause they don't have a clue. Barnum & Bailey said it best.

Notice the schematic from the site for Generator Interlock that Tommu56 posted ........... looks almost exactly as I described.

Electrically speaking, they are exactly the same. Some differences though:

1. The interlock kit prevents both utility and generator mains from being closed.
2. The power inlet eliminates the double-male plug which is used in traditional backfeeding.

I have seen the automatic transfer switches for whole house generators. There is nothing fancy about them, they just re-route the source of power through the main breaker. Smaller manual units also come in various flavors. I currently use a SquareD lug sub panel with two double-pole branch breakers as mains. One is utility main and the other is genny main. There is an interlock kit to prevent both being closed at the same time.

 

[check]

At the cottage, we have a 17 KW Kohler propane-powered standby generator with an automatic transfer switch. It wasn't cheap, but we get power outages up there all the time (2.5 hours North of Toronto), and we needed a lot of standby power for the outdoor hot tub which we run all winter. Since we are only there intermittently, we needed an automatic standby switch so the generator comes on automatically (it does so within 10 seconds) when the power goes out, and shuts off again when main power is restored.

We avoided having to disconnect the meter during installation by (a) taking all the circuit breakers out of our main panel, (b) installing a single, 100-amp breaker, (c) running a cable out from that breaker to the automatic transfer switch, which then runs out to a brand new panel that we bought, and then (d) putting all the old breakers into the new panel. Note that for this procedure you only need to use a non "service entrance" transfer switch for the standby generator (it is cheaper anyways), which can just be mounted on the wall at a convenient location close to the other panels.

We also left our previous portable generator sub-panel in place (which was just a 60-amp sub-panel with a safety isolator plate and a few critical breakers in it), just in case we wanted to use our portable generator some time (e.g., if power went out in the summer when we were at the cottage and could control everything manually). The reason for this idea was that the big 17 KW propane standby generator uses a LOT of propane, at a cost of about $80-$100 per day. Our portable 5500 W gasoline powered generator, on the other hand, uses regular gasoline at a much cheaper rate.

So, we have the best of both worlds, and safety, too. (I hadn't realized, however, that, as cycle_gator pointed out, you can still get power feeding through your ground and neutral with the little generator sub-panel! Is there a way of perhaps isolating this little panel by running a separate ground wire out of it to a separate grounding rod, and then disconnecting the ground that comes from the main panel? I guess you would have to disconnect the metal conduit between the main panel and the small generator sub-panel, since it also acts as a ground, but then what? Use PVC conduit? But isn't that illegal for interior applications?)

 

[rjkobbeman]

Sub panels should have their ground and neutral isolated. In other words, the ground and netural should not be bonded in the sub panel. This prevents current from flowing on the ground between the sub and main panel in normal operation (no fault conditions).

In a case where a generator is connected to a properly installed sub panel, the neutral and ground in the generator should not be bonded. In other words, they should be isolated just like in the sub panel. (Some portable generators have their neutral and ground bonded because they were not originally intended to connect to a house.)

The generator's grounding to earth is achieved by the ground rod connected to the main panel.

If everything is wired correctly, there will be no current backfeeding to the utility -- neutral or otherwise. Regular two-pole breakers that disconnect the "hots" will achieve isolation.