Generator Power Transfer Switch - Electrical - Page 2 - DIY Chatroom Home Improvement Forum


Go Back   DIY Chatroom Home Improvement Forum > Home Improvement > Electrical

CLICK HERE AND JOIN OUR COMMUNITY TODAY...IT'S FREE!

Reply
 
Thread Tools Display Modes
Old 06-27-2012, 04:45 PM   #16
E2 Electrician
 
stickboy1375's Avatar
 
Join Date: Apr 2012
Location: Litchfield, CT
Posts: 5,163
Rewards Points: 2,118
Default

Generator power transfer switch


Quote:
Originally Posted by andrew79 View Post
The issue with the dpdt switch is that the neutral remains connected. In theory the guy trying to fix the power lines could get a whack off your genny if circumstances are right. I'm not sure what the rule is on neutrals in the states or even here in Canada code wise but every genny panel I've ever seen switches the neutrals out as well.
How do you propose a utility worker could get shocked?

Advertisement

stickboy1375 is offline   Reply With Quote
Old 06-27-2012, 08:18 PM   #17
Member
 
Join Date: Sep 2011
Posts: 90
Rewards Points: 75
Default

Generator power transfer switch


Quote:
Originally Posted by jburd964 View Post
This is great, I was looking to spend $300 on a DPDT switch. Going to get ahold of the permitting office, hopefully this will be good with them and they come up with some crazy crap. Thanks for everyone's input.

I'm not a professional., But I did stay at Holiday Inn Express last night.
Let us know what the local office has to say. BTW, your are going to need that 300 bucks when you go to buy the power cable. Six guage four conductor cord is $$$.
Auger01 is offline   Reply With Quote
Old 06-27-2012, 10:18 PM   #18
Member
 
jburd964's Avatar
 
Join Date: May 2009
Location: Louisiana
Posts: 218
Rewards Points: 150
Default

Generator power transfer switch


Where I'm at I can use Aluminium wire from utility company an it's about half the price of copper. But still going to be running 150'. I think I can get everything ran for less then $500.
__________________
Gun control isn't about guns, IT'S ABOUT CONTROL.
jburd964 is offline   Reply With Quote
Old 06-27-2012, 11:12 PM   #19
Master Electrician
 
Join Date: Mar 2010
Location: Toronto Ontario
Posts: 1,165
Rewards Points: 500
Default

Generator power transfer switch


Quote:
Originally Posted by stickboy1375 View Post
How do you propose a utility worker could get shocked?
house has a faulty ground, now you've got current travelling right back to the pole to a very large step up transformer, by the time the voltage gets jacked up it'll likely not have enough current to do to much harm but under the right conditions it's possible. If it weren't an issue they wouldn't put three pole disconnects in genny panels to switch the neutral out. Trust me if the lineman gets a whack they will be driving around to see who's got power and testing it. If a more serious injury happens then you might as well just lawyer up.
__________________
Sarcasm is my friend
I'm here to learn too, i do mostly commercial/industrial/new construction and this place is a great way to pick up tips on residential from some good electrical minds. Excuse the spelling, my phone has a mind of it's own.
andrew79 is offline   Reply With Quote
Old 06-27-2012, 11:19 PM   #20
Member
 
jburd964's Avatar
 
Join Date: May 2009
Location: Louisiana
Posts: 218
Rewards Points: 150
Default

Generator power transfer switch


I did talk to permit guy today, he said he didn't really care how the disconnect worked as long as it works. Sounded kinda shady to me but I'm going to email him photos of inter lock before purchasing anything.
__________________
Gun control isn't about guns, IT'S ABOUT CONTROL.
jburd964 is offline   Reply With Quote
Old 06-27-2012, 11:46 PM   #21
Member
 
Join Date: Oct 2010
Location: Cairns Australia
Posts: 2,710
Rewards Points: 2,380
Default

Generator power transfer switch


Quote:
Originally Posted by andrew79 View Post
The issue with the dpdt switch is that the neutral remains connected. In theory the guy trying to fix the power lines could get a whack off your genny if circumstances are right. I'm not sure what the rule is on neutrals in the states or even here in Canada code wise but every genny panel I've ever seen switches the neutrals out as well.
In australia most houses have only one hot line !
Due to the fact we run on 240v most houses can get enough power
on only one hot.

So with a DPDT switch we do switch the neutral line,
In fact it is mandatory to switch neutral
this is to fully prevent back feeding.

Bigger instalations use 3 phase,
and they use a big rotary cam type multi pole switch.

No split phases in Australia
its eiather 1 phase or 3 phase.
dmxtothemax is offline   Reply With Quote
The Following User Says Thank You to dmxtothemax For This Useful Post:
andrew79 (06-28-2012)
Old 06-27-2012, 11:55 PM   #22
Member
 
Join Date: Sep 2011
Posts: 90
Rewards Points: 75
Default

Generator power transfer switch


Here in the States, we only switch the neutral if the neutral is bonded at the generator. If the neutral is not bonded at the generator, then obviously the neutral is not switched.
Auger01 is offline   Reply With Quote
Old 06-28-2012, 05:35 AM   #23
E2 Electrician
 
stickboy1375's Avatar
 
Join Date: Apr 2012
Location: Litchfield, CT
Posts: 5,163
Rewards Points: 2,118
Default

Generator power transfer switch


Quote:
Originally Posted by andrew79 View Post
house has a faulty ground, now you've got current travelling right back to the pole to a very large step up transformer, by the time the voltage gets jacked up it'll likely not have enough current to do to much harm but under the right conditions it's possible. If it weren't an issue they wouldn't put three pole disconnects in genny panels to switch the neutral out. Trust me if the lineman gets a whack they will be driving around to see who's got power and testing it. If a more serious injury happens then you might as well just lawyer up.
If the generator has a faulty neutral, and all current seeks to get back to its own source, why would current flow to a utility X0 connection?
stickboy1375 is offline   Reply With Quote
Old 06-28-2012, 06:56 AM   #24
Member
 
jburd964's Avatar
 
Join Date: May 2009
Location: Louisiana
Posts: 218
Rewards Points: 150
Default

Generator power transfer switch


Would someone give me the layman explanation of 3 phase? I work in refinery and deal with 110v, 220v, 480v equipment but that's the limit. Why and how?
__________________
Gun control isn't about guns, IT'S ABOUT CONTROL.
jburd964 is offline   Reply With Quote
Old 06-28-2012, 10:35 AM   #25
Master Electrician
 
Join Date: Mar 2010
Location: Toronto Ontario
Posts: 1,165
Rewards Points: 500
Default

Generator power transfer switch


Quote:
Originally Posted by stickboy1375 View Post
If the generator has a faulty neutral, and all current seeks to get back to its own source, why would current flow to a utility X0 connection?
current doesn't seek to get back to it's own source, it looks for the easiest route to go to ground.

Quote:
Originally Posted by jburd964 View Post
Would someone give me the layman explanation of 3 phase? I work in refinery and deal with 110v, 220v, 480v equipment but that's the limit. Why and how?
the main reason 3 phase is used is for motor applications, with three phases running there's is always voltage at the armature and it allows the motor to run smoother and more efficient. A 3 phase system generally can carry more power on the same size wire as well. 3 phase services can handle around 1.5 time the power as it's equivalent single or split phase system. It also allows you to connect many mmore devices to a single circuit. For instance say you've got highbay lights that have a multi tap ballast, with a 100w bulb in it the one i looked up will draw .93A at 120V, .42A at 277V and .22A at 480V. So your looking at more than a 3 to 1 ratio on fixtures going from 120 to 480. Now this could be acheived with a high voltage single phase system as well but another advantage of the three phase system is that if it's engineered correct it will be balanced, so you have 8 lights on A phase 8 on B and 8 on C. These all share the same neutral and because you have a a blanced load on each leg you actually get 0 current comming back on the neutral. I'm sure there's a ton of stuff i missed but there's a start for you.

one other thing i should add is the calcs
in a 3 phase wye connection line current = phase current
line voltage = phase voltage * 1.732
in a 3 phase delta connection line voltage = phase voltage
line current = phase current * 1.732
__________________
Sarcasm is my friend
I'm here to learn too, i do mostly commercial/industrial/new construction and this place is a great way to pick up tips on residential from some good electrical minds. Excuse the spelling, my phone has a mind of it's own.
andrew79 is offline   Reply With Quote
The Following User Says Thank You to andrew79 For This Useful Post:
jburd964 (06-28-2012)
Old 06-28-2012, 04:54 PM   #26
Member
 
Join Date: Jan 2010
Location: Pennsylvania
Posts: 600
Rewards Points: 512
Default

Generator power transfer switch


Quote:
Originally Posted by andrew79 View Post
depending what you want to do with your generator you can pick up a generator panel from a big box store for around $160, it has the interlock built in. You basically feed one side of the main from a 30A breaker and the other side of the main from the generator. what i generally do is install a weather proof 30A twistlock plug on the outside of a house and run it to the genny panel. build them an extension cord with two male ends that plug into the wall and the genny. When the power goes out all they have to do is flip the genny panel breaker plug in the cord and fire up the genny and everything in the genny panel comes back on. It's an idiot proof install.
The idiots you've dealt with are obviously of a higher caliber. The ones I know would fire up the generator with the extension cord attached to it, but not the receptacle-- which is why I think a lot of people call those suicide cords. You could at least fix the live plug problem by simply installing an inlet instead of an outlet and providing a conventional 30A extension cord, right? I'm still not understanding how this keeps them from leaving the main breaker on and thus energizing the main. I'm sure you know all this stuff, but I'm concerned.
operagost is offline   Reply With Quote
Old 06-28-2012, 05:08 PM   #27
E2 Electrician
 
stickboy1375's Avatar
 
Join Date: Apr 2012
Location: Litchfield, CT
Posts: 5,163
Rewards Points: 2,118
Default

Generator power transfer switch


Quote:
Originally Posted by andrew79 View Post
current doesn't seek to get back to it's own source, it looks for the easiest route to go to ground.


Right, because we all know an electrical system will stop functioning when we pull the ground rod out of the ground... I hope you are kidding with that comment by the way.
stickboy1375 is offline   Reply With Quote
Old 06-28-2012, 06:21 PM   #28
Newbie
 
Join Date: Jun 2012
Posts: 2
Rewards Points: 10
Default

Generator power transfer switch


Make sure you account for proper voltage drop for 150' run. Looks like if you are running aluminum you will need 2AWG to stay under 3% drop.
triden is offline   Reply With Quote
Old 06-28-2012, 06:25 PM   #29
E2 Electrician
 
stickboy1375's Avatar
 
Join Date: Apr 2012
Location: Litchfield, CT
Posts: 5,163
Rewards Points: 2,118
Default

Generator power transfer switch


Quote:
Originally Posted by andrew79 View Post
depending what you want to do with your generator you can pick up a generator panel from a big box store for around $160, it has the interlock built in. You basically feed one side of the main from a 30A breaker and the other side of the main from the generator. what i generally do is install a weather proof 30A twistlock plug on the outside of a house and run it to the genny panel. build them an extension cord with two male ends that plug into the wall and the genny. When the power goes out all they have to do is flip the genny panel breaker plug in the cord and fire up the genny and everything in the genny panel comes back on. It's an idiot proof install.
Seriously?
stickboy1375 is offline   Reply With Quote
Old 06-28-2012, 11:43 PM   #30
Master Electrician
 
Join Date: Mar 2010
Location: Toronto Ontario
Posts: 1,165
Rewards Points: 500
Default

Generator power transfer switch


Quote:
Originally Posted by stickboy1375 View Post
Right, because we all know an electrical system will stop functioning when we pull the ground rod out of the ground... I hope you are kidding with that comment by the way.
i didn't say it would stop functioning, i said it will look for the easiest path to ground, not necessarily back to it's source. When you grab the hot and get shocked what happens? it hurts like hell. If the power were trying to go back to it's source it wouldn't bother running through you into the ground now would it.I guess technically speaking it's going through the ground back to it's source via the pole ground but at that point your just pulling straws. Unfortunately your going to argue with me over it for the sake of arguing anyways so there wasn't much point in explaining myself, but here it is anyways. If you happen to have a hot to ground fault while your generator is running you've suddenly put 120v on the neutral. If for some reason your panel bond is faulty as well you've now livened up a wire heading back out to the pole potentially putting oh say 4000v to 13000V on what's now become the load side of a very large step up transformer. Clearly it's an issue if it's not legal to do in Australia, and i'm relatively sure(don't have my code book nearby) it's also illegal in Canada as well. I realize that's it's fine to do in the states but the op is aussie so NEC has no bearing on him there.

Quote:
Originally Posted by operagost View Post
The idiots you've dealt with are obviously of a higher caliber. The ones I know would fire up the generator with the extension cord attached to it, but not the receptacle-- which is why I think a lot of people call those suicide cords. You could at least fix the live plug problem by simply installing an inlet instead of an outlet and providing a conventional 30A extension cord, right? I'm still not understanding how this keeps them from leaving the main breaker on and thus energizing the main. I'm sure you know all this stuff, but I'm concerned.
the way to hook up the genny cord is that it has a female end on one side of the cord and a male end on the other, The flange plug that goes onto the house has the male end so there's no live energized parts exposed at any time, Where the mains would be in the panel is two seperate 3 pole breakers with a mechanical interlock that prevents panel side power and genny side power from coming on at the same time. It's basically a fancy version of a panel interlock but what this does is swap out the neutral as well. Also it prevents anyone from turning on too many breakers and tripping your genny's breakers as well increasing the life of the genny as it's probably not going to be as loaded down. I can see where the confusion is, and your right to point it out, i put two male ends in a previous post instead of explaining the cord. I was in a bit of a rush. Thanks for catching it.

here's a link to a genny panel available here
http://www.homedepot.ca/product/60a-...ble-if-/941193

here's a link to what the wp genny plug on the house looks like
http://www.generatorfactoryoutlet.co...ducts/PB30.asp

Advertisement

__________________
Sarcasm is my friend
I'm here to learn too, i do mostly commercial/industrial/new construction and this place is a great way to pick up tips on residential from some good electrical minds. Excuse the spelling, my phone has a mind of it's own.

Last edited by andrew79; 06-29-2012 at 12:31 AM.
andrew79 is offline   Reply With Quote
Reply


Thread Tools
Display Modes

Posting Rules
You may not post new threads
You may not post replies
You may not post attachments
You may not edit your posts

BB code is On
Smilies are On
[IMG] code is On
HTML code is Off
Trackbacks are Off
Pingbacks are Off
Refbacks are Off


Similar Threads
Thread Thread Starter Forum Replies Last Post
Electrical transfer switch dougp23 Electrical 4 11-23-2011 04:22 PM
Portable Generator Transfer Switch Question Dave_T Electrical 1 11-21-2011 06:08 PM
Changing A Double Switch to a single pole switch and a dimmer switch loydbrahn Electrical 0 11-09-2011 12:00 AM
Meter Socket Manual Gen Transfer Switch Mainebob Electrical 3 05-11-2011 08:31 AM
fan/light switch buzzing mjlocat Electrical 4 05-23-2010 03:44 PM




Top of Page | View New Posts