PROPERLY Connect Generator to Home

Reply

  #1  
Old 12-02-14, 12:39 PM
W
Member
Thread Starter
Join Date: Oct 2012
Location: USA
Posts: 63
Received 0 Votes on 0 Posts
PROPERLY Connect Generator to Home

I recently purchased a portable generator that I would like to backfeed my house with during power outages and I absolutely want to make sure I'm doing it safely for both me and linemen. Attached is a picture to show you my current setup (installed by previous home owners). On the left is the main "Square D" panel with a 60 amp breaker at the very bottom right side which appears to be where the additional "QO Load Center" panel is fed into. From the QO Load Center panel, power leads to a 50 amp female receptacle in my garage.

From my research, I know first thing I need installed is an interlock kit. Is this possible with my current panel configuration? The 60 amp switch is very far from the main power switch and I'm assuming I will need to relocate the 60 amp switch.

Also, the 7,000 watt generator I bought has a 30 amp female outlet. How do you recommend I connect that to my 50 amp female receptacle? I talked to with an electrician today and he said I should make my own cord by splicing a 50 amp male end to a regular 30 amp cord (aka a suicide cord). Is there any other alternative?

Please let me know what steps are needed to make everything work safely. Thank you!

Name:  power.jpg
Views: 8635
Size:  40.2 KB
 
  #2  
Old 12-02-14, 12:53 PM
F
Member
Join Date: Mar 2006
Location: Wet side of Washington state.
Posts: 18,495
Received 36 Votes on 28 Posts
I talked to with an electrician today and he said I should make my own cord by splicing a 50 amp male end to a regular 30 amp cord (aka a suicide cord).
You did not talk to an electrician, you talked to a hack masquerading as an electrician.

DO NOT USE A SUICIDE CORD!
I have to go to the hospital for some tests, I'll post more later.
 
  #3  
Old 12-02-14, 01:06 PM
W
Member
Thread Starter
Join Date: Oct 2012
Location: USA
Posts: 63
Received 0 Votes on 0 Posts
I couldn't agree more, which is why I'm continuing to seek proper advice. Let's try to prevent this from becoming yet another "DON'T DO THAT" thread — instead, I'd like to talk about what are the proper ways to resolve my issue so that I and others can learn the right way. Thank you.
 
  #4  
Old 12-02-14, 02:16 PM
I
Forum Topic Moderator
Join Date: Feb 2005
Location: Near Lansing, Michigan
Posts: 10,943
Received 44 Votes on 42 Posts
Do you need to power the whole house, or would 6-8 circuits be ok? It would be really easy to replace the small subpanel with a transfer panel, replace the 50A female receptacle with a 30A inlet and you'd be all set.
 
  #5  
Old 12-02-14, 03:58 PM
lawrosa's Avatar
Super Moderator
Join Date: Dec 2010
Location: Galivants Ferry SC USA
Posts: 18,154
Received 63 Votes on 55 Posts
It would be really easy to replace the small subpanel with a transfer panel,
Why would he need to replace? Is that not a transfer panel as I see the wires from that manel to the individual circuits in the main panel...

replace the 50A female receptacle with a 30A inlet and you'd be all set.
Yes change the inlet outside to a 30 amp as stated..

From my research, I know first thing I need installed is an interlock kit. Is this possible with my current panel configuration? The 60 amp switch is very far from the main power switch and I'm assuming I will need to relocate the 60 amp switch.
Take a pic of that transfer panel or give us the make and model #...

Also, the 7,000 watt generator I bought has a 30 amp female outlet. How do you recommend I connect that to my 50 amp female receptacle?
Tell us the make and model of the generator. please

The issue you will have is with bonding, depending on what generator you have...

Your best bet IMO would be to get a transfer switch with nuetral switching...

Like this...

XRC0303C X Series - Reliance Controls Corporation


Let's try to prevent this from becoming yet another "DON'T DO THAT" thread instead, I'd like to talk about what are the proper ways to resolve my issue so that I and others can learn the right way. Thank you.

Furd will be glad to help you more in this area as will the other electricians. We will guide you what is correct and to code on this site.

But as you know there are a few ways to do what you want so you may get conflicting answers...

Let us know the generator make and model...
 
  #6  
Old 12-02-14, 04:45 PM
A
Member
Join Date: Mar 2010
Location: USA
Posts: 4,298
Received 110 Votes on 102 Posts
Normally a portable generator is connected to the house at a male receptacle (inlet) regardless of the type of transfer switch or interlock or transfer panel. Usually you would string a new cable from the primary breaker panel to any location of your choice for the male receptacle.

If you commandeer a cable to existing regular (female) 120/240 volt receptacle(s) for your generator then any regular receptacles still on that cable will never again be able to receive utility power. After that length of cable is used as the generator feed, the transfer method must ensure that it will never be connected to any panel busses at the same time utility power is connected to those busses.

A "transfer panel" (typically with 6 to 20 small transfer switches) is installed next to the panel with the branch circuits to receive generator power; it is not necessary to remove or replace any existing panel.
 

Last edited by AllanJ; 12-02-14 at 05:19 PM.
  #7  
Old 12-02-14, 05:12 PM
W
Member
Thread Starter
Join Date: Oct 2012
Location: USA
Posts: 63
Received 0 Votes on 0 Posts
Thank you for the feedback so far, much appreciated. More details below:

Main panel: Square D HOMC30UC Series S01 Type 1 Enclosure

Sub-panel: QO8-16L100S

Generator: 7000 Watt Elite Series | Portable Generators | Briggs & Stratton US

Current inlet box in garage that is attached to sub-panel: Leviton 50A NEMA 1A-50R

Cord I bought (not in use yet): Amazon.com : Reliance Controls PC3040 40-Feet 30-Amp L14-30 Generator Power Cord for Up to 7500-Watt Generators : Generator Cord Sets And Plugs : Patio, Lawn & Garden

Another inlet box I bought (not installed yet): Amazon.com: Reliance Controls PB30 L14-30 30 Amp Generator Power Cord Inlet Box For Up To 7,500 Watt Generators: Patio, Lawn & Garden

Also, regarding the sub-panel, it is in use all the time. The previous owners added that because they needed to wire a couple additional rooms in the house and some misc receptacles in the basement.

As far as I what I "need" running during a power outage, I'm certainly open to the idea of only running select breakers to keep on important things like water, heat, etc. but ideally I'd like to run the whole panel. Of course, I don't expect to be able to run everything off a 7k generator but by running the whole panel, I would be able to pick and choose what I operate during an outage.
 
  #8  
Old 12-02-14, 05:28 PM
lawrosa's Avatar
Super Moderator
Join Date: Dec 2010
Location: Galivants Ferry SC USA
Posts: 18,154
Received 63 Votes on 55 Posts
On that gen the nutral is bonded. So you either have to remove the bond from the generator or get a type of panel as I linked to.

Let use know what path you are going to take before we continue..
 
  #9  
Old 12-02-14, 05:32 PM
lawrosa's Avatar
Super Moderator
Join Date: Dec 2010
Location: Galivants Ferry SC USA
Posts: 18,154
Received 63 Votes on 55 Posts
Also a definate is to change the inlet as you linked to....

http://www.amazon.com/gp/product/B000BQT47S/
 
  #10  
Old 12-02-14, 05:45 PM
lawrosa's Avatar
Super Moderator
Join Date: Dec 2010
Location: Galivants Ferry SC USA
Posts: 18,154
Received 63 Votes on 55 Posts
What circuits are on that sun panel if I may ask? Lights, Boiler, furnace??? etc....
 
  #11  
Old 12-02-14, 05:56 PM
W
Member
Thread Starter
Join Date: Oct 2012
Location: USA
Posts: 63
Received 0 Votes on 0 Posts
The neutral bond issue is not something I'm familiar with but I'm guessing I do not want to modify the generator and void the warranty. Knowing this, it sounds like I have no choice but to install a transfer switch, is that correct? Again, this area is new to me but is there a basic style switch that I can easily install without needing to rework my main and sub-panels? For example, if I'm going to replace my 50A inlet with 30A, could I simply add the transfer switch at that time?

When I change the inlet from the 50A to the 30A, is there any concern with the 30A not fitting the larger 50A wire? I'm not a pro but I think the current 50A wire is either 6 or 8 and I'm wondering if that's too big to fit the 30A inlet.

The sub-panel does not have essential circuits (nothing I would need running during a power outage) but it does have circuits to some of the bedrooms. Therefore, I always leave the sub-panel on.

Thanks again for the help.
 
  #12  
Old 12-02-14, 07:09 PM
CasualJoe's Avatar
Member
Join Date: Jan 2010
Location: United States
Posts: 10,765
Received 97 Votes on 87 Posts
  #13  
Old 12-02-14, 07:20 PM
A
Member
Join Date: Mar 2010
Location: USA
Posts: 4,298
Received 110 Votes on 102 Posts
If I were doing the project, I would not modify the generator in a manner that may void the warranty, for example not spelled out in its instructions.

If an "incompatible generator and house" were hooked together leaving neutral and ground bonded in each, no harm will come to that.

You can keep a 50 amp inlet provided that everything continuing on to the panel is 50 amps rated such as a 50 amp breaker set to backfeed the panel, or any components with lesser amperage ratings protected with smaller valued breakers.. This way you could substitute a 50 amp generator at a later date. It's okay to construct an extension cord or adapter with 50 amp (female) receptacle and 30 amp plug for today's generator.
 

Last edited by AllanJ; 12-02-14 at 07:39 PM.
  #14  
Old 12-02-14, 07:36 PM
lawrosa's Avatar
Super Moderator
Join Date: Dec 2010
Location: Galivants Ferry SC USA
Posts: 18,154
Received 63 Votes on 55 Posts
If this ends up with neutral and ground bonded in two places, so be it. No harm will come to that.
How can you suggest this allan when it not to code??? You cannot have two bonds....

IMO also forget about the interlocks... Get the proper panel... Most locality s dont alow the interlock and IMO no reason to power the whole panel.. Its emergency power....
 
  #15  
Old 12-02-14, 07:46 PM
CasualJoe's Avatar
Member
Join Date: Jan 2010
Location: United States
Posts: 10,765
Received 97 Votes on 87 Posts
Most locality s dont alow the interlock and IMO no reason to power the whole panel.. Its emergency power....
I disagree. I have not run into a locality that doesn't allow an interlock if it is from the panel manufacturer. There are aftermarket interlocks out there though that sometimes will not be allowed. The OP has a 7,000 watt generator, I see no problem backing up the entire panel for convenience as long as the OP remembers the limitations of the 30 amp circuit.
 
  #16  
Old 12-02-14, 08:09 PM
lawrosa's Avatar
Super Moderator
Join Date: Dec 2010
Location: Galivants Ferry SC USA
Posts: 18,154
Received 63 Votes on 55 Posts
The OP has a 7,000 watt generator, I see no problem backing up the entire panel for convenience as long as the OP remembers the limitations of the 30 amp circuit.
The OP does not want to lift the bond on the gen. How will he do this with an interlock???? Make sense?
 
  #17  
Old 12-03-14, 01:14 AM
F
Member
Join Date: Mar 2006
Location: Wet side of Washington state.
Posts: 18,495
Received 36 Votes on 28 Posts
The OP does not want to lift the bond on the gen. How will he do this with an interlock?
The only method short of an isolation transformer (I've never even heard of one being used in this situation) would be to NOT connect the equipment grounding conductor between the generator frame and the service panel in the house.

The problem is in eliminating a parallel path for normal return currents which an equipment grounding conductor would become if connected to "ground" at both ends. Eliminating the equipment grounding conductor in the interconnect cable, in my opinion, results in a very minor possibility of not tripping the generator-mounted circuit breaker under ground fault conditions. The circuit breaker will still actuate under overload or short circuit faults.

Ideally a neutral switching device would be used but that is impossible with an interlock.
 
  #18  
Old 12-03-14, 07:20 AM
W
Member
Thread Starter
Join Date: Oct 2012
Location: USA
Posts: 63
Received 0 Votes on 0 Posts
To summarize what I'm hearing, it sounds like:

1) An interlock kit is not possible with my current setup and to do it correctly, I would actually need to replace the entire panel.

2) The other (less safe) option would be to keep everything as is and construct a cord with 30A/50A ends as AllanJ mentioned. To me, that sounds like a suicide cord, unless I'm misunderstanding.

Unfortunately, I do not see replacing the panel anytime soon due to limited funds. I absolutely want to do whatever I can to make operation of the generator safe but I also need to choose the least expensive path to do so.
 
  #19  
Old 12-03-14, 07:34 AM
I
Forum Topic Moderator
Join Date: Feb 2005
Location: Near Lansing, Michigan
Posts: 10,943
Received 44 Votes on 42 Posts
No, you can use the interlock as long as your local code allows interlocks and your inspector will approve it. There are some aftermarket interlocks that inspectors tend not to like because they mount to the panel cover instead of the breaker itself. The ones directly from the panel manufacturer are ok in most areas.

The issue is whether or not you should modify the generator to unbond the neutral and ground inside the generator wiring compartment, usually by removing a wire from a screw. Doing so could theoretically cause you warranty problems if the generator ever needs service. It is slightly safer to unbond the connection when using the generator attached to the house. When using the generator stand-alone the connection must be bonded. Some people modify the generator to add a switch if they intend to use the generator stand-alone and attached to the house.
 
  #20  
Old 12-03-14, 07:45 AM
W
Member
Thread Starter
Join Date: Oct 2012
Location: USA
Posts: 63
Received 0 Votes on 0 Posts
Thank you for clarifying the bond issue. I assumed unbonding was a more involved process but if all it requires is disconnecting the ground wire screwed to the generator frame, I'm fine doing that.

So if that takes care of the generator bond issue, I'm still a little confused on what the next best step is after that. Do I continue with the interlock kit? Or make up my own 30A/50A cord and keep everything as is?
 
  #21  
Old 12-03-14, 10:57 AM
A
Member
Join Date: Mar 2010
Location: USA
Posts: 4,298
Received 110 Votes on 102 Posts
The 50 amp to 30 amp cord I suggested has one female (the 50 amp end) and one male receptacle so it is safe to use. If the male receptacle on the side of the house is 30 amps then you would just need a cord with both ends 30 amp.

This takes care of hooking up the generator to its feed wiring but the other half of the problem, hooking up the generator feed wiring to the rest of the system, needs to be addressed.

The latter is handled using an interlock in the fed panel or a single transfer switch upstream of the fed panel or a unit with several small transfer switches next to the panel.

You may continue with the interlock kit provided it fits in the panel and properly performs its function (physical interlocking) and is an allowable method in your city.
 
  #22  
Old 12-03-14, 11:05 AM
W
Member
Thread Starter
Join Date: Oct 2012
Location: USA
Posts: 63
Received 0 Votes on 0 Posts
I already have a 50A female receptacle in the garage (coming off the sub-panel) so if I modify the gen cord to have another 50A female end, how do I connect the two? If you have specific parts in mind, please list them so I can visual what you're describing. Thank you.
 
  #23  
Old 12-03-14, 11:13 AM
A
Member
Join Date: Mar 2010
Location: USA
Posts: 4,298
Received 110 Votes on 102 Posts
You may not connect the generator to a female receptacle on the wall regardless of the ampere ratings.

You must use a male receptacle as described previously. You must use transfer switches or interlocks as described previously.

Some transfer boxes have a male receptacle on them. Then you would just need to string a standard cord from the generator through a basement window to do the hookup.
 

Last edited by AllanJ; 12-03-14 at 11:50 AM.
  #24  
Old 12-03-14, 11:33 AM
ray2047's Avatar
Member
Join Date: Mar 2006
Location: USA
Posts: 33,582
Received 13 Votes on 11 Posts
A suicide cord is called a suicide cord for very good reasons.

The generator is running. The end at the 50 amp receptacle comes out. You have bare metal prongs that if touched will electrocute you.

There is no safe way to use the receptacle you have.
 
  #25  
Old 12-03-14, 11:57 AM
I
Forum Topic Moderator
Join Date: Feb 2005
Location: Near Lansing, Michigan
Posts: 10,943
Received 44 Votes on 42 Posts
I think there is some confusion over the terminology. The OP is pretty clear they understand the suicide cord is wrong.

Starting at the generator, there is a female receptacle. The cord then should have a male plug on the generator side and a female plug on the house side. At the house, you have a male inlet, which has the prongs of a male plug, but they are fixed inside a recessed cavity which accepts the female end of the generator cord. The inlet is then hard wired into the interlocked breaker or transfer panel terminals using a building wire like #10-3 Romex.

Specific parts, you should have a L14-30 twist lock receptacle on the generator. You need a 10 gauge cord with an L14-30 male on one side and L14-30 female on the other side. The house needs an inlet box with a L14-30 inlet (see the pattern ) Keep the receptacle you have in your toolbox in case you want to hook up an electric range or welder someday.
 
  #26  
Old 12-03-14, 11:59 AM
W
Member
Thread Starter
Join Date: Oct 2012
Location: USA
Posts: 63
Received 0 Votes on 0 Posts
I understand the dangers of a suicide cord, hence I don't want to do that.

Here's a related question: so far, everyone agrees that I need to replace the female receptacle in my garage with a male. The problem I see there is the sub-panel that leads to the garage receptacle is always powered ON. If I now replace the garage receptacle with a male, doesn't mean I'll always have a dangerous male receptacle in my garage that could shock someone?
 
  #27  
Old 12-03-14, 12:07 PM
F
Member
Join Date: Mar 2006
Location: Wet side of Washington state.
Posts: 18,495
Received 36 Votes on 28 Posts
You cannot use the connection to the sub-panel. You will have to move the cable serving the 50 ampere receptacle from the sub-panel and connect it to the interlocked generator CB you will install in the service panel.

OR, just forget about the existing 50 ampere receptacle and circuit and run a new generator inlet circuit from the service panel interlocked circuit breaker (to be installed) to the generator inlet (male receptacle).
 
  #28  
Old 12-03-14, 12:18 PM
W
Member
Thread Starter
Join Date: Oct 2012
Location: USA
Posts: 63
Received 0 Votes on 0 Posts
Ok, I'm starting to see the light, thank you again for your help and patience.

You just said something that interests me a lot: leave the current 50A receptacle alone and install a separate interlock and inlet. The reason I like that is I would like to buy a welder eventually and could use the existing 50A.

So in order to install a new, separate inlet and install a new interlock on the main panel, what am I looking at for parts? I already purchased this inlet, if that will work: Amazon.com: Reliance Controls PB30 L14-30 30 Amp Generator Power Cord Inlet Box For Up To 7,500 Watt Generators: Patio, Lawn & Garden. For the interlock, could I buy a kit from Generator InterLock Kit Manual Transfer Switch and be done?
 
  #29  
Old 12-03-14, 12:36 PM
F
Member
Join Date: Mar 2006
Location: Wet side of Washington state.
Posts: 18,495
Received 36 Votes on 28 Posts
Whether or not you may use an interlock kit from that supplier is dependent upon your LOCAL code and inspector. To properly meet the National Electrical Code (NEC) requirements the interlock must be designed to prevent it from easily being bypassed. Some jurisdictions have interpreted that as meaning if the interlock can be defeated by merely removing the panel cover it does NOT meet the requirement of not easily being bypassed. Since LOCAL code always trumps the model (national) code ONLY your local inspection agency can answer the question.

That aside, the answer is yes, the inlet box and the generator cord you have previously linked are the proper items.
 
  #30  
Old 12-03-14, 06:59 PM
CasualJoe's Avatar
Member
Join Date: Jan 2010
Location: United States
Posts: 10,765
Received 97 Votes on 87 Posts
You said your main panel was a Homeline. I gave you the info on Square D Homeline interlocks in post #12

Depending on exact Homeline panel you have, you'll probably need one of the Square D interlock kits.

Square D 100 Amp Homeline Load Center Outdoor Generator Inter-Lock Kit-HOMCRBGK1 at The Home Depot

Square D Homeline Outdoor Generator Inter-Lock Kit-HOMRBGK2C at The Home Depot
If your main panel is 200 amp, Square D makes interlocks for them too.
 
  #31  
Old 12-04-14, 09:10 AM
W
Member
Thread Starter
Join Date: Oct 2012
Location: USA
Posts: 63
Received 0 Votes on 0 Posts
I was able to reach the previous homeowners and they said they had also used a grounding rod on the generator outside. This must be related to the bonding issue previously mentioned in this thread. Does my particular gen need a ground rod as well, or do I simply disconnect the ground to the frame of the unit?
 
  #32  
Old 12-04-14, 03:32 PM
A
Member
Join Date: Aug 2010
Location: USA
Posts: 118
Received 0 Votes on 0 Posts
You need two things to make this a compliant install:

ONE: Square D interlock attachment part # QO2DTI

It is 18.71 bucks at zoro.com. Put a 60 amp breaker in the sub and connect it to the wires from the 60 amp breaker in the main. Looks like the supanel is full do you will need two tandem breakers to make the space. Another alternative is to connect two circuits to one breaker if they are lightly loaded. You can do that because QO breakers are rated for two wires. Put QO2DTI attachment between the 60 feed in the sub and the 50 amp breaker from the inlet. It "interlocks" the breakers so only one is on at a time. Congratulations, you just changed that panel to a generator panel and didn't get raped for 300 bucks.

SQUARE D Interlock Attachment - G7578067 at Zoro

TWO: A 50 amp INLET

Replace the 50 amp outlet with an 50 amp inlet. Don't use a thirty. You cant put a 30 amp inlet on a circuit with a 50 amp breaker. Make a cord for your generator with a 30 amp male for the gen side and a 50 amp female for the house side. If you upgrade to a bigger generator later all you have to change is the cord. The home wiring doesn't need to change.

Reliance Controls Power Inlet Box, 50A, 120/240V By GeneratorFactoryOutlet.com

You are welcome.

P.S. Forget about the ground rod. The generator is connected to the house ground via that 4th green wire in the cable.
 

Last edited by Auger01; 12-04-14 at 04:37 PM.
  #33  
Old 12-04-14, 03:55 PM
lawrosa's Avatar
Super Moderator
Join Date: Dec 2010
Location: Galivants Ferry SC USA
Posts: 18,154
Received 63 Votes on 55 Posts
IMO your not being given the best advice here in several posts...

Answer this please and is most important.

1. Are you going to unbond the generator? Is your generator able to be unbounded?

2. What circuits do you want to power? Are there more then 10?

Normal requirements are refridgerator, heat, lights, some outlets, well pump if you have one.

A 7000 watt gen? Is that starting watts or run watts? You dont want to run a gen at max capacity. Youll burn it up. Lets say 6000 watts.

That 6000 watts will power 3000 watts per side of the panel. Cut that to 50% load and thats 1500 watts per side... You must balance the load on each winding of the gen or you will have severe vibration issues...


( I dont know why many want to power the whole panel. Its emergency power. How often and how long are you usually without power?)

I have 6 circuts only and got through Hurricane Sandy on 12 gallons of fuel for 9 days. House was 72 degrees. Had hot water, heat, lights and food...My biggest load was my well pump...

Just a note this was a 3250 watt gen 120 volt only..............

I was one of 5 people in my whole development that had power of 200 homes...Compared to them I was living at the Hilton. Since we are all wells here no one could flush their toilets... Ewwwww!!!!


Well sorry I am rambling... just trying to show reality.
 

Last edited by lawrosa; 12-04-14 at 04:29 PM.
  #34  
Old 12-04-14, 03:59 PM
CasualJoe's Avatar
Member
Join Date: Jan 2010
Location: United States
Posts: 10,765
Received 97 Votes on 87 Posts
You need two things to make this a compliant install:

ONE: Square D interlock attachment part # QO2DTI
This part is for a QO series panel, but will it also work on a Homeline panel like the OP has? Square D used to have an interlock for to work on either series, but this isn't the one I am thinking of.
 
  #35  
Old 12-04-14, 04:34 PM
A
Member
Join Date: Aug 2010
Location: USA
Posts: 118
Received 0 Votes on 0 Posts
Casual Joe:

That QO2DI would be for the subpanel, assuming he has the circuits that he wants to power located in the sub. If not, relocating the feed from the inlet to the main and using the parts you mentioned would be the better way to go.
 
  #36  
Old 12-04-14, 04:59 PM
lawrosa's Avatar
Super Moderator
Join Date: Dec 2010
Location: Galivants Ferry SC USA
Posts: 18,154
Received 63 Votes on 55 Posts
P.S. Forget about the ground rod. The generator is connected to the house ground via that 4th green wire in the cable.
If the OP does not unbond the gen then he has two bonds. Not to code.... This should not be suggested without an explanation...
 
  #37  
Old 12-04-14, 05:34 PM
A
Member
Join Date: Mar 2010
Location: USA
Posts: 4,298
Received 110 Votes on 102 Posts
Here is an explanation for not unbonding neutral and ground at a generator.

If the bond cannot be eliminated without substantial disassembly of the generator or voiding its warranty then it is better to leave that bond in place.

This will not compromise overcurrent protection since the breaker in the generator (should have one) will trip regardless of whether return overcurrent arrives on the neutral or the equipment grounding conductor or both if they are bonded at the generator.
 
  #38  
Old 12-04-14, 07:29 PM
A
Member
Join Date: Aug 2010
Location: USA
Posts: 118
Received 0 Votes on 0 Posts
Auger01

P.S. Forget about the ground rod. The generator is connected to the house ground via that 4th green wire in the cable.

lawrosa

. If the OP does not unbond the gen then he has two bonds. Not to code.... This should not be suggested without an explanation...

I don't follow you.

If he does unbond the generator, he needs to forget about an external ground rod because the generator is already grounded via the ground wire in the cable.

If he doesn't unbond the generator he needs forget about the external ground, because the generator is still grounded via the ground wire in the cable to the house ground. Yes there are two bonds and no it isn't to code but only because of the two bonds. What he does or doesn't do with an external ground rod isn't going to change that fact.

Bottom line, either way forget about the extra ground rod. It isn't going to make two bonds code compliant either way. It could however set up some ground loop currents which are undesirable.
 
  #39  
Old 12-04-14, 07:44 PM
lawrosa's Avatar
Super Moderator
Join Date: Dec 2010
Location: Galivants Ferry SC USA
Posts: 18,154
Received 63 Votes on 55 Posts
If the bond cannot be eliminated without substantial disassembly of the generator or voiding its warranty then it is better to leave that bond in place.

This will not compromise overcurrent protection since the breaker in the generator (should have one) will trip regardless of whether return overcurrent arrives on the neutral or the equipment grounding conductor or both if they are bonded at the generator.

Allan your an electrician?

Read this please...

http://www.oshaprofessor.com/Portabl...rds%203-05.pdf

Then please read here and post back...

https://cumminspower.com/www/literat...ingAC-2-en.pdf
 
  #40  
Old 12-09-14, 07:21 AM
W
Member
Thread Starter
Join Date: Oct 2012
Location: USA
Posts: 63
Received 0 Votes on 0 Posts
Ok, I have been taking the knowledge gained here and doing more homework. Here's what I've come up with:

I want to install a transfer switch, no doubt about it. As already mentioned, this seems to be the safest route.

If I understand everything correctly, I believe I can leave my current sub-panel and 50A inlet completely alone and install the transfer switch directly into the main panel.

Also, by using a transfer switch, I believe 1) I will not need an interlock kit and 2) the switch will ensure I can never backfeed to the grid and possibly harm someone. Correct?

I'm looking at this unit but I'm confused on the watts. It says up to a 7,500 gen in the title but then says 4,500 in the item description: http://www.amazon.com/Reliance-31406...fer+switch+kit

Is the correct switch for my application?
 
 

Thread Tools
Search this Thread
 
Ask a Question
Question Title:
Description:
Your question will be posted in: