Relay and Contactor based GENSET BACKFEED PREVENTER?

Page 2 of 3  

wrote:

I'm not sure what your concern for arcing in the circuit breaker is about. Circuit breakers are made to be turned on and off under load. You could always install wiring and a circuit breaker bigger than the rated capacity of your generator.
John G.
Add pictures here
<% if( /^image/.test(type) ){ %>
<% } %>
<%-name%>
Add image file
Upload
I don't claim to have really followed it, but do know that the contacts on my TS relay fused closed. Unless your device accomodates that (on the line contacts) safely, it is no good.
Add pictures here
<% if( /^image/.test(type) ){ %>
<% } %>
<%-name%>
Add image file
Upload

What is a TS relay?
I want to use a large contactor, rated for way more than what my generator can supply. My genset generates about 28A, whereas the contactor that I would use is rated for 30A.
i
Add pictures here
<% if( /^image/.test(type) ){ %>
<% } %>
<%-name%>
Add image file
Upload
On Tue, 06 Sep 2005 15:42:47 GMT, Ignoramus25850

You want AT LEAST a 50 amp rated contactor, at 500 volts, for a safety factor. 30 amps is cutting it a bit fine, since you do not have zero crossing switching.

Add pictures here
<% if( /^image/.test(type) ){ %>
<% } %>
<%-name%>
Add image file
Upload
On Tue, 06 Sep 2005 12:06:57 -0400, snipped-for-privacy@sny.der.on.ca

Thanks. I have a 3 pole 75A contactor that I am planning on using. Should be plenty for a 28A generator.
i
Add pictures here
<% if( /^image/.test(type) ){ %>
<% } %>
<%-name%>
Add image file
Upload
wrote:

Not a good idea at all!! A transfer switch has to be designed so if it fails it absolutely can not back feed into the utility power. If your contactor fails closed, and believe me it does happen, your generator can back feed per to the utility.
I install and service standby generators, if one of our transfer switches fail there is absolutely no way it will back feed power. The transfer switch may fail in either position, but no way will it cause a back feed! Greg
Add pictures here
<% if( /^image/.test(type) ){ %>
<% } %>
<%-name%>
Add image file
Upload

install it and get it inspected.
Add pictures here
<% if( /^image/.test(type) ){ %>
<% } %>
<%-name%>
Add image file
Upload
riggghhttt. anyone with a bit of sense can install a transfer switch.
Steve Spence Dir., Green Trust, http://www.green-trust.org Contributing Editor, http://www.off-grid.net http://www.rebelwolf.com/essn.html
ATP* wrote:

Add pictures here
<% if( /^image/.test(type) ){ %>
<% } %>
<%-name%>
Add image file
Upload

I've seen plenty of simpler electrical jobs screwed up or just poorly executed by people with more than a bit of sense. In any case, it has to be listed and inspected per the local utility regulations.

Add pictures here
<% if( /^image/.test(type) ){ %>
<% } %>
<%-name%>
Add image file
Upload
maybe in your community, but not in mine. I wired my whole house, panels and entrance. The power company only dropped to the meter on the pole. that was the end of it. I did the rest.
Steve Spence Dir., Green Trust, http://www.green-trust.org Contributing Editor, http://www.off-grid.net http://www.rebelwolf.com/essn.html
ATP* wrote:

Add pictures here
<% if( /^image/.test(type) ){ %>
<% } %>
<%-name%>
Add image file
Upload
On Wed, 07 Sep 2005 18:51:51 -0400, Steve Spence

must pass inspection. After that you must live in it for five years before you can sell it. This is done to prevent bad wiring done by people who are building spec homes. Not that everybody who builds a spec home is going to do a bad job. Just that some people will skimp and not use qualified people to do the wiring. ERS
Add pictures here
<% if( /^image/.test(type) ){ %>
<% } %>
<%-name%>
Add image file
Upload
wrote:

Strange! Here a homeowner can pull a permit to do most anything. Then the job must pass inspection just like anything else and you are done with the process.
Vaughn
Add pictures here
<% if( /^image/.test(type) ){ %>
<% } %>
<%-name%>
Add image file
Upload
Eric R Snow wrote:

That seems like a pretty harsh regulation. Here I believe you can legally wire your own house, but you're supposed to have it inspected afterwards, and certainly before you sell it. But we also have a stupid new law which means that only qualified electricians can buy consumer units. Most people with time and good practical skills, but little money, aren't going to pay an electrician to wire their workshop. They'll find a consumer unit from a friend, or a demolition site, or a dumpster. It just drives work underground. Another sad example of European over-regulation!
Chris
Add pictures here
<% if( /^image/.test(type) ){ %>
<% } %>
<%-name%>
Add image file
Upload
On Thu, 8 Sep 2005 00:37:16 +0000 (UTC), Christopher Tidy

Christopher, what do you mean by a consumer unit?
i
Add pictures here
<% if( /^image/.test(type) ){ %>
<% } %>
<%-name%>
Add image file
Upload

Lets see how my grasp of european terms is..
consumer unit = Breaker panel (made of plastic, with DIN rails)
RCD = GFI (or something very similar)
T+E = Twin+Earth = Romex
ring main = circuit fed from both ends (from the same breaker)
--
-- Welcome My Son, Welcome To The Machine --
Bob Vaughan | techie @ tantivy.net |
  Click to see the full signature.
Add pictures here
<% if( /^image/.test(type) ){ %>
<% } %>
<%-name%>
Add image file
Upload
Eric R Snow wrote: ....

So far, so good...

How could they possibly enforce that?
Add pictures here
<% if( /^image/.test(type) ){ %>
<% } %>
<%-name%>
Add image file
Upload
On Thu, 08 Sep 2005 08:30:58 -0500, Duane Bozarth

hardly any reasons. In WA the inspection is done by Labor & Industries. They come out when they come out. And do hold up projects. My father-in-law is a licensed electrician. I flew him up to WA to help with the wiring to make sure it all done to code. He told me that in Santa Clara county in CA the inspectors have 24 hours to show up and do the inspection. If they don't then the wiring can be covered and is considered to be up to code. BTW, just because a house is wired by a "professional" and has passed inspection it doesn't mean that the wiring will be done correctly. My last house had all the wiring in the garage and laundry room backwards. So all the white wires were hot and the black wires neutral. The problem was in a junction box where someone had connected the wires in reverse. This box had undisturbed mud and paint on it from the original drywall. So the wiring had not been changed by any previous owners. ERS
Add pictures here
<% if( /^image/.test(type) ){ %>
<% } %>
<%-name%>
Add image file
Upload
On Wed, 07 Sep 2005 18:51:51 -0400, Steve Spence

Some of the most screwed up DIY installations I've ever had to rework were done by engineers and (literally) 'Rocket Scientists' who thought they knew better. I think half the parts the former owner used for the additions at this house (before we bought it) "fell off the loading dock" at Rocketdyne in the '60's, though I can't prove it.

In EVERY community I know of, the electrical utility won't tie onto a power panel and provide a meter unless the panel has been inspected and approved as safe by /somebody/ referred to as the Authority Having Jurisdiction or AHJ.
If there isn't a city building inspector, the job falls back to the county or parish level. If it's on state or federally owned property, then their inspector has the authority. The power utility doesn't want the legal liability if someone gets hurt or killed, so they insist on it.
Now after the AHJ has passed the installation, the utility has connected the feed, and both parties are long gone, /then/ you can do additional work without a permit, and cheat as much as you want, with one gigantic caveat: As long as they never see it.
And if the AHJ comes back to check something else and sees you have cheated, now you have a problem. They can (and will) force you to fix it. If you don't, their ultimate recourse is to call the utility and tell them to cut the feed and pull the meter, the installation is no longer safe. Darkness and quiet quickly ensues. (*)
(* At least on things run from utility power, noting the crosspost.)
Except for mobile homes / manufactured housing in California, where inspection of the meter pedestal and outside wiring is a city or county responsibility like normal, but anything electrical inside or on the coach itself is inspected by a State bureaucrat. Our local mobile home inspector drives into Western LA County from Riverside, where the closest office is.
--<< Bruce >>--
--
Bruce L. Bergman, Woodland Hills (Los Angeles) CA - Desktop
Electrician for Westend Electric - CA726700
  Click to see the full signature.
Add pictures here
<% if( /^image/.test(type) ){ %>
<% } %>
<%-name%>
Add image file
Upload
"Bruce L. Bergman" wrote:

Local electric utility linemen do some pretty screwed up stuff as well. The house I'm in now had a utility lineman as an owner previously and I'm still correcting his mess.
Little things like 240v feeds to the shop wirenutted and left exposed at ground level, as in individual THHN comes out through hole in brick, wirenut to more THHN and then disappear underground. The same 240v feed to the shop is fed from separate 20a and 30a single pole breakers in the damn panel.
All of the mess to the shop and indeed the crappy stab-lock main panel are on the agenda to be replaced with a good 200a QO panel for the house, a 100a QO for the shop, all new wire to the shop in some proper sch 40 PVC underground to the shop, etc. I figure it's a good weekend project, not counting pre-trenching in the conduit.
There are plenty of other less significant things that I've been fixing along the way as well. I do however like the four steel light poles he used to support the carport roof along side the shop and the two others with HID lights (mismatched of course) that light the yard.
Pete C.
Add pictures here
<% if( /^image/.test(type) ){ %>
<% } %>
<%-name%>
Add image file
Upload
I hear this all the time. High wire janitors are not electricians or engineers.
wrote:

Add pictures here
<% if( /^image/.test(type) ){ %>
<% } %>
<%-name%>
Add image file
Upload

Related Threads

    HomeOwnersHub.com is a website for homeowners and building and maintenance pros. It is not affiliated with any of the manufacturers or service providers discussed here. All logos and trade names are the property of their respective owners.