Options for feeding a subpanel off a residential panel

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Andy1845c

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Southern Minnesota
Hey guys,

I want to build a shop and would ideally like to put a 200 amp service in it. My house has a 200 amp residential panel id like to feed it off of. I work for an electrical contractor, but I do almost exclusively industrial work. I am wondering if one of you residential guys has some ideas for me.

I have eaton type BR breakers. I can't find anything over 150 amp for snap in breakers and that breaker looks to be hella expensive.

I could have the poco change the service point from my house to the transformer pad (rural setting) and refeed the house but I don't really want to go that route if I can avoid it. I could install a single phase feed through panel and change the panel in my house, also not super appealing. I could live with a 100 amp shop circuit (honestly probably would be fine) or spend the billion dollars they want for the 150 amp breaker and be a little closer to what I set out for in amperage.

Does anyone know of anything legal that I am not thinking of? Id like to just bolt lugs onto the studs where the main breaker feeds the buss and tap off that, but I assume the panel is not listed to be used like that and the inspector will not go for that.

Also, I only have one large lug on my neutral bar. I THINK I can bolt another one on, but need to take some time when the wife is not home and shut the panel down and clean it up a little so I can see better. Any cleaver solutions there?

IMG_0465.jpg
Attached is a picture of the panel.
 
electrofelon said:
My opinion, in this order:

1. Just use a 100 amp feeder. You know deep inside it will be totally fine.

2. Use a 125 amp feeder. 125 double poles aren't that much

3. Use a subfeed terminal block like this. https://www.amazon.com/CUTLER-HAMMER-BRS225-Subfeed-2-300kcmil/dp/B008KNKT7S

4. Use 230.40 exception 3. Set a wireway or box after the meter to make the tap.
Click to expand...

I agree, option #1 would be my first choice. Then the feed block in option #3 would be my next choice. I wouldn't even consider option #4 as that's too much work for what the OP needs.
 
Little Bill said:
. I wouldn't even consider option #4 as that's too much work for what the OP needs.
Click to expand...

I don't necessarily agree. Depending on the specifics, I could take making the tap over routing a 150-200 amp feeder from outside to inside and fighting to land those conductors in a messy crowded panel. 100 amp makes a subfeed alot less miserable IMO.
 
+1 on the 100a option. To me, there's no reason to try to take 200a from a loaded 200a panel. Even with HVAC, you'll never need the power of a small house; no cooking, hot water, laundry, etc.
 
Thanks guys!

I am liking option #2 - The subfeed block looks promising. I did not know that existed so I am glad I asked here.

100% agree 100 amps would probably be fine. That may be what I do. The only reason I was leaning toward 200 is I have various welder/phase converter/machine tools that I would like to set up and having some headroom on the electrical would be nice should I ever want to have more than one thing going on at a time out there.

There are a lot of circuits that can be combined in that panel to clean it up. Halfway thinking about setting a small gutter up above it to straighten it out. Ill have to open it back up and measure to see if I could make the bending radius work on the wire.
 
LarryFine said:
+1 on the 100a option. To me, there's no reason to try to take 200a from a loaded 200a panel. Even with HVAC, you'll never need the power of a small house; no cooking, hot water, laundry, etc.
Click to expand...
I decided one time to check my total connected load.

I have a big house, 200A service, no A/C, gas heat, all electric appliances.... I fire up the double oven on broil, turn on the dryer, plug in the crock pot, crank up the stereo, turn on the tv, clock radios in everyone's bedrooms, turn on every light in every room, turn on all the hair dryers and curling irons (I have two daughters and a wife), microwave some popcorn, brew a pot of coffee, make some toast, and then run outside and check with my amp meter, and I cant't draw 70A, but I'm close. The amp meter is bouncing back and forth between 67 and 68A. I run back inside and open the door on the fridge and freezer and crank up the stereo even more. I just know I can break 70A.

My wife comes outside, hollers at me, "What the .... are you doing?!!!!"

"Important electrical research," I say.

She says nothing and goes back inside. I hear the stereo go silent. I never did break trough to 70A.
 
ActionDave said:
I decided one time to check my total connected load.

I have a big house, 200A service, no A/C, gas heat, all electric appliances.... I fire up the double oven on broil, turn on the dryer, plug in the crock pot, crank up the stereo, turn on the tv, clock radios in everyone's bedrooms, turn on every light in every room, turn on all the hair dryers and curling irons (I have two daughters and a wife), microwave some popcorn, brew a pot of coffee, make some toast, and then run outside and check with my amp meter, and I cant't draw 70A, but I'm close. The amp meter is bouncing back and forth between 67 and 68A. I run back inside and open the door on the fridge and freezer and crank up the stereo even more. I just know I can break 70A.

My wife comes outside, hollers at me, "What the .... are you doing?!!!!"

"Important electrical research," I say.

She says nothing and goes back inside. I hear the stereo go silent. I never did break trough to 70A.
Click to expand...
:thumbsup:

Most of our derating has been engineered toward one goal......the sale of CU

~RJ~
 
ActionDave said:
I decided one time to check my total connected load.

I have a big house, 200A service, no A/C, gas heat, all electric appliances.... I fire up the double oven on broil, turn on the dryer, plug in the crock pot, crank up the stereo, turn on the tv, clock radios in everyone's bedrooms, turn on every light in every room, turn on all the hair dryers and curling irons (I have two daughters and a wife), microwave some popcorn, brew a pot of coffee, make some toast, and then run outside and check with my amp meter, and I cant't draw 70A, but I'm close. The amp meter is bouncing back and forth between 67 and 68A. I run back inside and open the door on the fridge and freezer and crank up the stereo even more. I just know I can break 70A.

My wife comes outside, hollers at me, "What the .... are you doing?!!!!"

"Important electrical research," I say.

She says nothing and goes back inside. I hear the stereo go silent. I never did break trough to 70A.
Click to expand...

I was thinking the same thing at my house....until one cold winter day my wife was busy working in the house. I was in the shop. She calls me and says, "Hey come in the house for a minute...the electric panel is humming real loud." So, I break into running sprint to the house, blast though the back door, run up to the panel, and, sure enough, the panel is almost roaring! So I ask her what she has turned on that is using electricity. She says, "Well.....the house felt cold so I turned up the heat (30KW worth of back-up coils all running at once), I'm washing clothes (washer, water pump, septic pump, and water heater all running 6KW), I'm also drying clothes (6KW), Ironing clothes(1.5KW), doing dishes (dish washer heater 1.5KW).....oh and I almost forgot....I'm cleaning the oven (self cleaning....another 10KW).
Turns out I had not yet learned the importance of running panel feeders (top fed panel with bottom fed feeders) together through gutters and so I had run one leg up each side of the panel. The full 230A of current I was pulling in the panel at that moment was creating a big inductor which was vibrating the panel cover. Needless to say, I corrected that situation shortly....lucky I had enough length in the feeders to re-route one of them to the other gutter. Also had a lengthy discussion with my sweet-heart about the electrical load that is imparted on the service when the heat gets abruptly turned up high enough to cause all the back-up coils to run at once! The house now has a 400A service. Not required by NEC, but we did pull 230A on a 200A main for quite a while that day and I didn't like it one bit! :D
 
Eaton BJ-220 is the 200A breaker for that panel. (Check the panel label.)

But I would probably follow the other advice and use a subfeed lug or a smaller feeder.
 
ActionDave said:
I decided one time to check my total connected load.

I have a big house, 200A service, no A/C, gas heat, all electric appliances.... I fire up the double oven on broil, turn on the dryer, plug in the crock pot, crank up the stereo, turn on the tv, clock radios in everyone's bedrooms, turn on every light in every room, turn on all the hair dryers and curling irons (I have two daughters and a wife), microwave some popcorn, brew a pot of coffee, make some toast, and then run outside and check with my amp meter, and I cant't draw 70A, but I'm close. The amp meter is bouncing back and forth between 67 and 68A. I run back inside and open the door on the fridge and freezer and crank up the stereo even more. I just know I can break 70A.

My wife comes outside, hollers at me, "What the .... are you doing?!!!!"

"Important electrical research," I say.

She says nothing and goes back inside. I hear the stereo go silent. I never did break trough to 70A.
Click to expand...

Funny story! Important electrical research! Can only imagine what it would take to trip a 200 Main
 
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