Backfeeding panel with generator power

[tdkkart]

Google Generlink, I see a couple utility companies are quoting $625 installed, probably not too bad considering what a regular transfer switch setup will cost you installed.

 

[NWOhioChevyGuy]

Well, very prompt reply from Generlink.com.

MA23-N Generlink, Non-Surge 30amp $650
MA23-S Generlink, Surge 30 amp $725
MA24-N Generlink, Non-Surge 40amp $750
MA24-S Generlink, Surge 40amp $825


The other option is putting in a combination Meter Socket - Transfer switch. This was from our utilities website.
MFG: Durham
Catalog#: SB204DT100B

http://www.durhamcompany.com/Catalog/Durham Catalog/pg_0047.htm

 

[Rickochet]

Well, very prompt reply from Generlink.com.

MA23-N Generlink, Non-Surge 30amp $650
MA23-S Generlink, Surge 30 amp $725
MA24-N Generlink, Non-Surge 40amp $750
MA24-S Generlink, Surge 40amp $825


The other option is putting in a combination Meter Socket - Transfer switch. This was from our utilities website.
MFG: Durham
Catalog#: SB204DT100B

http://www.durhamcompany.com/Catalog/Durham Catalog/pg_0047.htm

Do you know what the price ranges are for the combos you shared from Durham?

 

[Rickochet]

The following print is a very basic illustration of how a transfer switch operates. Use carefully thought out plans when trying to connect a generator. It is not just a line mechanic (we have women who perform line work too) who is at risk when a generator is installed improperly.

Take the time to do it right and you will never be sorry. My motto for many things such as this is:

"It takes less time and money to do the job right than it does to explain why it wasn't."

----especially if you are going to do battle with the legal system......

 

[trainer]

So the simplest transfer switch would be a DPDT switch installed between the meter and main breaker?

 

[tdkkart]

So the simplest transfer switch would be a DPDT switch installed between the meter and main breaker?

This is how my transfer switch is set up.

Power comes in through the meter to the main panel.

Main panel has a 50 amp breaker feeding a subpanel containing essential circuits. Well pump, furnace, frig outlet, family room outlets and few light bulbs.

Leads from the 50 amp breaker go through a DPDT knife switch on their way to the subpanel.

Knife switch gets input from either the 50amp breaker or the generator, output goes to the subpanel.

When the power goes out, plug the generator cord into the twistlock receptacle on the back of the house, fire the generator, pull the knife switch to feed power from the generator to the sub panel.

Simple, effective, and safe.

 

[Torque1st]

So the simplest transfer switch would be a DPDT switch installed between the meter and main breaker?

The simplest transfer switch would be the breaker interlock mechanism. It takes the least wiring, fewest connections for the fewest trouble spots, and if you look at the function closely it is just a DPDT switch. The cost factor makes it the best option besides it is simplest, effective, and safe.

 

[Mr_fixit]

The simplest transfer switch would be the breaker interlock mechanism. It takes the least wiring, fewest connections for the fewest trouble spots, and if you look at the function closely it is just a DPDT switch. The cost factor makes it the best option besides it is simplest, effective, and safe.

Here... Here... What I could never understand is that everyone has such a STRONG opinion on what TO do and what NOT to do, but almost no one knows about this inexpensive, simple option. The part itself sells retail for about $70. And a generator inlet might cost you $50.00

The only drawback is that Square D make them for Homeline and Square D QO 100 amp or 200 amp panels. So if you have an older panel or a different brand panel, you HAVE to spend ALOT more money to do things right.

 

[precisionsc54]

Just get an automatice transfer switch unless you want to risk anothers life.

 

[NWOhioChevyGuy]

Do you know what the price ranges are for the combos you shared from Durham?

I sent in a request to my Electrical supplier and have not got a response yet. I did a quick look online and did not find a supplier.

When I get a response with some $'s I'll post it.

 

[mmg440]

Just get an automatice transfer switch unless you want to risk anothers life.

Automatic or manual, The transfer switch if the part needed. I don't think a manual positive interlock transfer method is any more or less dangerous the a automatic system. Both prevent generator current from entering the line to the grid. I have a manual generator that won't automatically come on line so the automatic switch would be money spent for equipment unneeded in my situation. However a manual transfer switch or box interlock system would be a wise investment

 

[NWOhioChevyGuy]

FYI: I finally recieved an email back on the price of the socket transfer switch we discussesd above.

That socket transfer switch I posted on above runs $370 from my electrical supplier. I would have to have it installed.

 

[tdkkart]

FYI: I finally recieved an email back on the price of the socket transfer switch we discussesd above.
That socket transfer switch I posted on above runs $370 from my electrical supplier. I would have to have it installed.

That's dirt cheap considering that it's a plug-in solution. Requires no additional equipment, no alterations to your present system. Clean and simple, automatic operation.

 

[NWOhioChevyGuy]

Yep,

Simple!
Utility Approved!
Safe!
Cheap!!!!!!!

All the right words.

 

[Ezzie]

I have been considering installing an interlock on my breaker panel so I can connect a generator to it. As I investigate this, it is apparent that the rules in Canada are far different than in the USA. So for the Canadians in the crowd, I thought I would post this here so we can all be better informed.

It appears that in Canada, the use of interlocks is illegal, you must use a transfer switch. Here is a response from a tech. support guy at Schneider when I asked him about the QOCGK2 interlock for use on my QO series load center.

"The QOCGK2 is not CSA approved and can not be installed in a panel in Canada. Even if you find a way to install it on the breakers, it does not meet the Canadian Code.

With reference to the document F0102AN9901EP, many Authorities have taken the stance that if you do not have a permanent generator, you have to be able to switch the neutral. You would have to check with you local inspector to see what they require.

We do not offer a product similar to the QOCGK2 in Canada. It is required to be able to lock you main breaker off so the hasp is a required part of the breaker to meet CSA requirements."

This explains why the Canadian load centres appear to be different than the US ones even from the same manufacturer.

And to further complicate the issue, the type of transfer switch you must use is dependant on whether the generator's neutral is bonded to the frame OR has a floating neutral. Here is a link to the Application Note on the topic that has been published by Schneider Canada on the topic.

http://members.rennlist.org/warren/Gen_Panels_Appl_Note_EN.pdf

 

[geaugafletcher]

Without a doubt, a transfer switch is the proper (and legal) way to do things.

For anybody who'd like to know more about how the whole backfeed thing works, do a google search for John De Armond's comments on the matter.

 

[tcianci]

Connecting a generator to a panel without benefit of opening the main breaker will immediately overload the generator and open the on-board circuit breakers.Failing that it would just plain kill your generator. While from a technical standpoint, you are backfeeding the service entrance and everyone else attached to it, the possibility of whacking a serviceman on a pole somewhere is just about nil. I would be very interested in any published information provided by a utility or a newspaper that documents someone being injured or killed from this activity.

 

[Stuart in MN]

I would be very interested in any published information provided by a utility or a newspaper that documents someone being injured or killed from this activity.

Here's one example: http://www.electricenergyonline.com/?page=show_news&id=38786

 

[abnorm]

http://www.powerlineman.com/lforum/archive/index.php/t-711.html

 

[walrus]

I would be very interested in any published information provided by a utility or a newspaper that documents someone being injured or killed from this activity.

Google is your friend, you get hits for linemen killed by backfeeding generator

 

[Torque1st]

They have rules and training for linemen to ground wires out but everyone human slips up sometime. If by chance an idiot homeowner that backfeeds improperly with his generator aligns with a very tired lineman deadly things happen.

During ice storms here in KC KCP&L have had a single lineman out clearing the lines with a bucket truck alone. To do it alone seems absurd. I have spent many hours out there in the sleet watching them in case the unthinkable happens.

 

[sdowney717]

https://docs.google.com/viewer?url=http://www.chudov.com/tmp/interlock_kit.pdf

generator interlock for a homeline or a QO box with part numbers.
simple stamped sheet metal
shut off main breaker
turn on gen breaker
device keeps them locked out apart from each other
easy to balance loads by turning on and off breakers when needed

 

[Mr_fixit]

Stupidity seems to get alot of people killed. I'm waiting for the reality TV show.

 

[Teken]

I have been considering installing an interlock on my breaker panel so I can connect a generator to it. As I investigate this, it is apparent that the rules in Canada are far different than in the USA. So for the Canadians in the crowd, I thought I would post this here so we can all be better informed.

It appears that in Canada, the use of interlocks is illegal, you must use a transfer switch. Here is a response from a tech. support guy at Schneider when I asked him about the QOCGK2 interlock for use on my QO series load center.

"The QOCGK2 is not CSA approved and can not be installed in a panel in Canada. Even if you find a way to install it on the breakers, it does not meet the Canadian Code.

With reference to the document F0102AN9901EP, many Authorities have taken the stance that if you do not have a permanent generator, you have to be able to switch the neutral. You would have to check with you local inspector to see what they require.

We do not offer a product similar to the QOCGK2 in Canada. It is required to be able to lock you main breaker off so the hasp is a required part of the breaker to meet CSA requirements."

This explains why the Canadian load centres appear to be different than the US ones even from the same manufacturer.

And to further complicate the issue, the type of transfer switch you must use is dependant on whether the generator's neutral is bonded to the frame OR has a floating neutral. Here is a link to the Application Note on the topic that has been published by Schneider Canada on the topic.

http://members.rennlist.org/warren/Gen_Panels_Appl_Note_EN.pdf

I was hoping someone would chime in from Canada regarding this metal plate thing . . . In a pinch I almost went this route, but all the con's and the feed-back by the GJ members here which I respect have changed my mind in this unit . . .

There are things I would consider going cheaper . . . This happens not to be one of them great thread and info as always!

 

[sdowney717]

Well if your gen set is mis wired and you energize the neutral at the main panel the hots are going straight to ground.

here it is for $65
http://ecatalog.mecampbell.com/default.aspx?page=item detail&itemcode=SQDHOMCGK2

here is a good shot of one installed
http://www.johnnypopper.com/forums/index.php?showtopic=16393

 

[Teken]

Well if your gen set is mis wired and you energize the neutral at the main panel the hots are going straight to ground.

here it is for $65
http://ecatalog.mecampbell.com/default.aspx?page=item detail&itemcode=SQDHOMCGK2

here is a good shot of one installed
http://www.johnnypopper.com/forums/index.php?showtopic=16393

My thoughts are this would be a great addition with a manual transfer switch. You can never be too careful so this would be a nice thing to have.

Someone is making a killing on a simple piece of metal . . .

 

[mrb]

Someone is making a killing on a simple piece of metal . . .

not really. between designing and making the thing, UL listing for USA and Canada, warehousing, and all the other costs involved, they probably make $5 or $10 off the thing.

 

[Teken]

not really. between designing and making the thing, UL listing for USA and Canada, warehousing, and all the other costs involved, they probably make $5 or $10 off the thing.

Totally forgot those aspects of the product . . . UL certification is one of the large costs factors in the initial stage to get a product listed and being able to have the logo displayed.

I'm just jealous that I didn't come up with such a useful and simple design is all!

 

[sdowney717]

here is what the label looks like.
Did not know how to put the long lines in
and it looses the spacing when posted

UTILITY
S Interlocked Circuit Breakers
T 1. Turn UTILITY circuit breaker “OFF”
A 2. Turn OFF all branch circuit breakers
N 3. Slide this interlock plate up --------->
D 4. Turn STANDBY circuit breaker “ON”
B 5. Turn “ON” branch circuit breakers
Y supplying essential circuits.
-- Reverse procedure to return to
UTILITY circuit breaker

my panel is triple grounded
I have a standard copper rod
I have a second multistrand 4 gauge wire to the copper cold water line
And the twisted ground bare wire return to the grid from the utility.

Utility is just 2 hots and a ground coming into the box, there is no neutral on the utility pole, neutral is the ground at ground potential. which is that large twisted multistrand bare aluminum wire which goes from house to pole and the whole area. AFAIK, all the connected homes all share the same common ground. I think they even ground the poles.

A lot will have to go wrong to destroy my electrical ground

 

[mrb]

here is what the label looks like.
Did not know how to put the long lines in
and it looses the spacing when posted


my panel is triple grounded
I have a standard copper rod
I have a second multistrand 4 gauge wire to the copper cold water line
And the twisted ground bare wire return to the grid from the utility.

Utility is just 2 hots and a ground coming into the box, there is no neutral on the utility pole, neutral is the ground at ground potential. which is that large twisted multistrand bare aluminum wire which goes from house to pole and the whole area. AFAIK, all the connected homes all share the same common ground. I think they even ground the poles.

A lot will have to go wrong to destroy my electrical ground

the line from the utility is the neutral. your 'ground wires' downstream of your main bonding jumper (connection from neutral to ground at your service) are Equiment Grounding Conductors'. The purpose of bonding (what many call grounding) is to provide a low impedance path back to the source for fault current so a protective device (breaker or fuse) will trip during a fault. The water pipes are bonded for safety, the copper rod is your grounding electrode which is for lightning, discharge of static and stray currents, etc. The ground rod doesnt have anything to do with the function of the aforementioned bonding. Your house is not 'triple grounded', it is properly grounded. Remove any one of those three things and you have a problem.

 

[sdowney717]

think about it, the utility bare 'neutral' is also bonded to ground.
This bare wire will carry a current return to the utility but it is still a bare wire. Never heard of someone shocked off it if everything is as it should be. I wonder how much current is flowing threw that wire for the 120 volt potential of hot to bare neutral.

I also wonder if that utility 'neutral' ground was cut if my house ground would handle the load. I think it would, but I suppose you might be able to burn threw a single 6 gauge ground wire that would be carrying all the current on the 120 volt side to ground.
I think it is best to have at least 2 separate ground wires grounded to earth. The code here says a single solid copper wire 6 gauge to 2 ground rods 7 or 8 feet apart, or one wire grounded to cold water line and a separate wire to a single ground rod

 

[sdowney717]

I recall when redoing the panel, I called the city and also talked to the inspector and the cold water ground was considered a true ground, not just a static charge safety issue. And they also expressed a like for it as a ground connection, saying it is an excellent ground.

 

[mrb]

think about it, the utility bare 'neutral' is also bonded to ground.
This bare wire will carry a current return to the utility but it is still a bare wire. Never heard of someone shocked off it if everything is as it should be. I wonder how much current is flowing threw that wire for the 120 volt potential of hot to bare neutral.

I also wonder if that utility 'neutral' ground was cut if my house ground would handle the load. I think it would, but I suppose you might be able to burn threw a single 6 gauge ground wire that would be carrying all the current on the 120 volt side to ground.
I think it is best to have at least 2 separate ground wires grounded to earth. The code here says a single solid copper wire 6 gauge to 2 ground rods 7 or 8 feet apart, or one wire grounded to cold water line and a separate wire to a single ground rod

the line from the utility is the neutral, not a ground. that line carries the imbalance between the two hots. For example say you have a 200 amp service, are pulling 75 amps on Phase A and 150 amps on Phase B, the neutral will carry 75 amps (150 on A-75 on B=75).

If the utility neutral were cut, those 75 amps are not going to magically flow through the earth to get back to the utility transformer. In an open neutral situation the voltage on each phase in your house is going to vary from zero to 240v depending on what loads are on. Many people have had expensive electronics ruined from an open neutral.

Again, ground rods and other grounding electrodes such as a bonded water pipe do nothing to return current to the source. The reason for grounding electrodes is lightning and to limit voltages imposed by accidental contact with higher voltage power lines. During normal operation of your electrical system grounding electrodes do actually nothing and have nothing to do with Equipment Grounding which is the connection of metal conduits, the ground pin in receptacles, etc to the ground bar in the panel.

Here is some good reading http://ecmweb.com/topics/grounding-vs-bonding/index.html

Look at fig 2 here http://ecmweb.com/grounding/electric_grounding_vs_bonding/

 

[sdowney717]

I noticed driving down the street, all the utility poles are grounded.
They call this setup a multi grounded neutral.
I always thought that if the neutral broke then the grounding system would return power back to the utility sytsem threw the ground. I will keep looking into this. I know in some areas grounds are more difficult to obtain a good ground for the system.

To me I always think of the grounded neutral is basically ground at a zero earth potential, with the entire neutral wire system grounded creating a very large network of grounded returns. Yeah I know current will preferentially flow the path of least resistance which is the "Multi grounded neutral" network, involving all the homes, utility poles etc...

http://www.psc.state.fl.us/consumers/utilitypole/en/allutilitypoleinfo.aspx
# Multi-Grounded Neutral (MGN)
Distribution lines have a grounded neutral conductor to provide a return path for the electricity. On many poles, if the distribution line is also connected to the ground wire (or grounding conductor), the line is called a multi-grounded neutral.

Actually curious how well the ground returns power if the neutral somehow is broken.
Not willing to test this myself, but somewhere somebody knows

That neutral return I am grounded by way of all the interconnected homes and utility pole grounds, it is electrically connected anything else makes no sense.

 

[Torque1st]

Actually curious how well the ground returns power if the neutral somehow is broken.
Not willing to test this myself, but somewhere somebody knows

If the neutral to your split phase service is broken the voltages on your house outlets etc go completely nuts. It burns things out and is very dangerous. The ground stake is not a power return.

 

[walrus]

Actually curious how well the ground returns power if the neutral somehow is broken.

Had a branch come down on my service, the neutral was spliced in the air by the power company(triplex). Middle of winter, wasn't living in the house at the time, somehow my furnace(actually a boiler) was still running. Was several days before the power company could get there, power outages everywhere so I had to wait. Furnace never shut down so it must return some current

 

[Torque1st]

Had a branch come down on my service, the neutral was spliced in the air by the power company(triplex). Middle of winter, wasn't living in the house at the time, somehow my furnace(actually a boiler) was still running. Was several days before the power company could get there, power outages everywhere so I had to wait. Furnace never shut down so it must return some current

The current returns through the other Line.

 

[sdowney717]

Just learning something here, check this out folks, current can return thru the ground and some AC distribution systems apparently use it
http://www.absoluteastronomy.com/topics/Ground_(electricity)

Power transmission

In Single Wire Earth Return
Single wire earth return
Single wire earth return or single wire ground return is a single-wire transmission line for supplying single-phase electrical power from an electrical grid to remote areas at low cost. It is principally used for rural electrification, but also finds use for larger isolated loads such as water...

(SWER) AC electrical distribution systems, costs are saved by using just a single high voltage conductor for the power grid, while routing the AC return current through the earth. This system is mostly used in rural areas where large earth currents will not otherwise cause hazards.

 

[sdowney717]

still looking into this some more.
You could test ground flow by driving a ground rod, take a hot wire and touch it to ground and see what happens. I dont know if only one ground rod gets a good enough ground to create a short condition, but it would be interesting to find out.

It turns out that the power company uses the Earth as one of the wires in the power system. The planet is a good conductor, and it's huge, so it makes a handy return path for electrons.

http://science.howstuffworks.com/electricity6.htm

 

[sdowney717]

http://www.rivervalleynewspapers.com/strayvoltage/stories/index.php?Story=20000423_rule.inc
here some people are complaining about 'dirty power' where utility power flows threw the ground return and affects the cows on the farm.

"The reality is with a multigrounded system, part of the current associated with customer load flows through the earth," Cook said

solution is an ungrounded neutral return but then that is really unsafe i think.

A 1995 survey by the Minnesota Public Utilities Commission of 48 utilities found that 59 percent of the current returns through the earth. The Michigan attorney general says as much as 75 percent of Consumers Energy returns through the earth.