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Old 11-23-2017, 08:24 PM
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terry lingle terry lingle is offline
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Default repurposing a circuit panel

I often need a simple transfer switch for safe installation of a stand by generator.
What I do is use a suitably sized circuit panel and make up a lock out plate so only one power source can be applied at a time
circuit protection is provided by upstream breakers on both inputs.
The breakers in the panel are fed in reverse and are used as switches.
The load is connected to the normal input terminals of the panel. I also transfer any demand loads to this panel.
Note that when using the generator input the customer must turn off all heavy loads in his house panel but can selectively run any load his generator is capable of supporting by turning every thing else in the panel off.

In this case the main feed is a 200 amp panel in the shop with the house fed from a 100 amp breaker in the shop panel. There is also a freezer circuit in the shop which will be transferred to the 15 amp breaker in the transfer panel.
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Old 11-23-2017, 09:24 PM
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I like it, simple and effective
I'd like the idea better with a padlock hoop, to moron proof it.
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Old 11-23-2017, 10:09 PM
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terry lingle terry lingle is offline
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It is a transfer switch in a home environment there is little point in a padlock as the service panel is 3 feet away.
In an industrial environment I would never do this I would use top quality specified equipment simply because of the required paper trail. Also the service is likely to be 600 volts and three phase in that situation.

In a "normal" home service I have supplied a small panel for the demand loads
put a 40 amp breaker in the main panel wired to a standard range receptacle. the input to the demand panel is a full rated range cord not one of the new ones with a reduced neutral conductor. the generator feeds a second range receptacle. In normal use the demant panel in plugged into the service fed receptacle. for generator just move the plug over. I label both receptacles
"TURN FEED BREAKERS OFF BEFORE MOVING PLUG"
This system as is the above panel is intended to prevent back feeding the grid in case of power outages.

What amazes me is the number of double male ended cord that people have made to power there home then called because there generator keeps blowing the breaker when they do not turn off the main in the house panel.
Fortunately I have not heard of any hydro side events attributed to this but it could result in a manslaughter charge in the worst case.
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Old 11-24-2017, 08:47 AM
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Quote:
Originally Posted by terry lingle View Post
What amazes me is the number of double male ended cord that people have made to power there home then called because there generator keeps blowing the breaker when they do not turn off the main in the house panel.
Fortunately I have not heard of any hydro side events attributed to this but it could result in a manslaughter charge in the worst case.
I hope those linemen are using hot line protocol on a 'dead' line. It is incredibly dumb to feed power into a powerline transformer.
As long as someone who really knows everything about electricity doesn't unbolt the slider plate, what you have is a great option. I need to copy that.
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Old 11-24-2017, 10:06 PM
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I may have to copy it as well.
I have seen commercial units set up in a similar fashion. I wish I could remember where.

I have a transfer switch that uses back to back breakers tied together with a bar making it impossible to have both breakers on at the same time.
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Old 11-24-2017, 10:32 PM
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Quote:
Originally Posted by rustythe4x4 View Post
I may have to copy it as well.
I have seen commercial units set up in a similar fashion. I wish I could remember where.

I have a transfer switch that uses back to back breakers tied together with a bar making it impossible to have both breakers on at the same time.
I saw a home made one like that a few years ago and thought it was a pretty nifty way to do it.
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Old 11-24-2017, 10:44 PM
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I have a set of linked breakers Here. They are pricey also the ones I have are both the same rating.
I would use them if the standby generator was capable of supplying the full load current. If that is not the case then two correct breakers and a panel will be less expensive
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Old 11-25-2017, 11:58 PM
Lowe.Buuck Lowe.Buuck is offline
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Thanks for a timely post.

I just purchased a Honda EU2000I and am working out how to power a few selected loads in the house.

I have a 5000w, 6000w and 9500w generators and a suicide cord to back-feed the house from the shop. The house has a 200a breaker/disconnect box right below the meter. So I can use that and/or the main breaker in the panel to disconnect from the grid.

The issue I wanted to address is the fuel consumption and power quality of the larger generators. I only had $225 invested in all three, however they burn a lot of fuel and some electronics don't like the power quality.

I went through the house and measured the start and running watts of most of the loads in the house. The house needs less than 1000w of 120v in the winter to keep critical loads operating. The EU2000I in Eco mode will use a fraction of the fuel, is much quieter and produces clean power.

I'm still trying to figure the best way to get 120v to 5 locations in the house. I realize that if I back-feed 120v from the shop I will only power one side of the main panel.

I could turn off all the 240v breakers, and then feed the 120v hot leg to both sides of the main panel.

The house mostly has 2 wire service. I am considering wiring 5 new 120v grounded runs for critical loads (basically pre-wired extension cords) and have been trying to figure the best way to power them with the Honda.

My thought was a separate panel for these new circuits keeping them totally separate from the existing wiring.

I could also use your transfer switch to feed this panel from a 15a breaker in the main panel when the grid power is up.

Any suggestions?
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  #9  
Old 11-26-2017, 12:28 AM
Samcord Samcord is offline
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Quote:
Originally Posted by Lowe.Buuck View Post



I could turn off all the 240v breakers, and then feed the 120v hot leg to both sides of the main panel.







Any suggestions?

Can't you move the 5 circuits to the same leg?
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  #10  
Old 11-26-2017, 12:47 AM
Samcord Samcord is offline
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I wanted to make it simple and safe. I installed one of these. So easy a cave man could operate it. No worries about shutting unnecessary loads off. The top row of switches are three position - utility, off, generator.

You basically loop the circuits from the utility breaker, through the transfer switch, and then to the load. You have two wires from the transfer switch that you route into the breaker panel. You disconnect the house wire from the breaker, then connect one wire from the transfer switch to the breaker, and splice the other wire to the house wire. You also have a single larger wire for common.

If I'm not home when the power goes out, I'm confident that my wife could handle it.

They make smaller ones with fewer circuits. Click image for larger version

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