Replacing 200 MB disco with MB panel

[iand74]

Hi

I have a customer who wants to replace a 200a main breaker disconnect with a 200a main breaker panel.

Existing situation is that the meter feeds a MB disco and the disco feeds a panel in another part of the house

If I replace the disco with a MB panel i will have to feed the existing panel (located elsewhere) off a breaker in the new panel.
I'm worried about landing the existing conductors (4/0 AL) on a breaker because the wire is so big. In my experience wire this big will pull a breaker right off the bus.

Has anyone ever done this or have any knowledge of any lug kits i could install in the new panel that i could land 4/0 AL in?

Let me know if you have any questions.

Thanks

 

[electricguy61]

Depending on the panel you buy, there are 200amp feed through lugs you can purchase.

http://cmsapps.sea.siemens.com/murray/murraycatalog/2008/08Murray_pdfs/08Murray_02/02_15.pdf

 

[Dennis Alwon]

A panel with feed thru lugs is a great idea if the wire feeding the sub panel is in conduit and rated 75C. If there is se cable that cable will now be rated 60C in most cases and will have to be protected at 150 amps since it will not carry the load of the entire dwelling. Many panels will not accept 15 amps on the bus. I know that many GE panels will accept 110 amps per finger max.

 

[Strathead]

confused

confused

Hi

I have a customer who wants to replace a 200a main breaker disconnect with a 200a main breaker panel.

Existing situation is that the meter feeds a MB disco and the disco feeds a panel in another part of the house

If I replace the disco with a MB panel i will have to feed the existing panel (located elsewhere) off a breaker in the new panel.
I'm worried about landing the existing conductors (4/0 AL) on a breaker because the wire is so big. In my experience wire this big will pull a breaker right off the bus.

Has anyone ever done this or have any knowledge of any lug kits i could install in the new panel that i could land 4/0 AL in?

Let me know if you have any questions.

Thanks

I am not sure what you consider a problem. If the new panel has a main breaker rated at 200 Amps, and a sub feed breaker rated at 200A, the design of the panel will be adequate for bend radius and wire size of 4/0 aluminum. Otherwise it would not be UL listed. There should be no problem with 4/0 aluminum in this case. If you are planning to feed the existing panel with less than a 200 amp breaker, there are two things to consider. Is the new breaker listed for use with 4/0 wire? If so, then you need to make sure the bending space per 312.6 and associated tables is adequate. If these are OK I would not be concerned with the wire pulling the breaker off. Just train the wire before you land it on the breaker.

Other solutions. Tap the load conductor after the existing disconnect and extend to the new panel. Install a gutter before the existing disconnect and tap the condutors in the gutter. Extend to the new panel and the existing disconnect.

 

[Dennis Alwon]

I am not sure what you consider a problem. If the new panel has a main breaker rated at 200 Amps, and a sub feed breaker rated at 200A, the design of the panel will be adequate for bend radius and wire size of 4/0 aluminum.

It is not that simple. Most 200 amp residential panels don't accept 150 or 200 amp breaker on the bus bar and feed thru would probably not be compliant.

Other solutions. Tap the load conductor after the existing disconnect and extend to the new panel. Install a gutter before the existing disconnect and tap the condutors in the gutter. Extend to the new panel and the existing disconnect.

Not compliant a the other panel is in another part of the house according to the op.

 

[Strathead]

It is not that simple. Most 200 amp residential panels don't accept 150 or 200 amp breaker on the bus bar and feed thru would probably not be compliant..

Agreed, regarding the 125A standard breaker slots. Since I work mostly commercial, I don't see enough loadcenters to know what is readily available, however, what I said still holds up and stands true. And a feed though would be OK if the main breaker was rated for the current carrying capacity of the sub feed wire. We are both assuming that the original installation is code compliant (I.E. bonded in the right place.

Not compliant a the other panel is in another part of the house according to the op.

I guess you again missed what I wrote. If you put a gutter on the line side of the disconnect, you are not replacing the disconnect. It would still be there to protect the conductors for the interior panel. A tap in the conductors to the new Main breaker panel. grounding and bonding in the gutter. Perfectly legal.

 

[iand74]

thanks for the responses...

the existing installation is correct re: bonding.


i have some questions re the lug kits:

can you put a lug kit on a snap in murray panel?

is there additional overcurrent protection on the lug kit or does it rely in the MB in the panel?

Can you buy a snap-in breaker panel with feed through lugs in it already?

I suppose the easiest thing to do would be to downsize the panel to 125 amps and put in a regular breaker...?

 

[suemarkp]

Maybe. Has Murray been absorbed by Siemens? This link for Siemens references some murray panels or breakers for some of the items listed. You'd have to dig deeper to see if the subfeed lugs will work with your specific panel if purchasing a Siemens version.

http://www.sea.siemens.com/us/inter...ial-Murray/docs/electricenter_accessories.pdf

Yes, you can buy residential panels with built in feed through lugs. Here's a Cutler-Hammer one:
http://www.amazon.com/Eaton-Corpora...HKGC/ref=sr_1_1?ie=UTF8&qid=1330392656&sr=8-1

The F in the part number suffix indicates it comes with feed thru lugs.

 

[Cow]

I would just buy a panel with factory feed thru lugs. Simple as that.

Next option would be to buy a regular panel and buy an accessory sub feed lug kit.

Or buy a combo metermain and replace everything, if this is all outside.