feed through lugs question

Merry Christmas

anbm

Senior Member
250A main CB panel, 208Y/120V, 3PH, can we use this panel to power an existing 225A MLO 208Y/120V, 3PH panel
via feed through lugs with 250A wires (4 #250KCM)? Any codes issues? The two panels are 120 feet away from each other.
 

anbm

Senior Member
You cannot use a 250 amp OCPD to protect a 225 amp panelboard.
I am thinking about tap rule, the feeder from 250A panel to 225A panel is 250A feeder, should the tap rule starts at 225A panel? but all branch circuits in 225A panel are protected by appropriate CBs, so tap rule is met.... Am I wrong?
 

Dennis Alwon

Moderator
Staff member
Location
Chapel Hill, NC
Occupation
Retired Electrical Contractor
I am thinking about tap rule, the feeder from 250A panel to 225A panel is 250A feeder, should the tap rule starts at 225A panel? but all branch circuits in 225A panel are protected by appropriate CBs, so tap rule is met.... Am I wrong?
What tap rule lets you go 120 feet away unless it is outside?

Using the feed thru lugs is not IMO a tap
 

MyCleveland

Senior Member
Location
Cleveland, Ohio
Look at the DISTANCE limitations on the tap rules and the fact the tap MUST terminate at an OCPD.

Trying checking with the panel mfg...may be able to swap out feed through lugs for a sub-feed CBer, otherwise just come off the lugs and set a CBer then run to your panel.
 

anbm

Senior Member
What tap rule lets you go 120 feet away unless it is outside?

Using the feed thru lugs is not IMO a tap
Got it, can a 225A fuses or breaker be installed in upstream panel feeds 250A panel?

Or ... can 250A CB be change to 225A breaker in 250A panel at site? (this is new panel).
 

Dennis Alwon

Moderator
Staff member
Location
Chapel Hill, NC
Occupation
Retired Electrical Contractor
Yes you can change the main breaker to 225 amps if that doesn't overload the panel. Can you just get a panel with a 250 amp buss or greater
 

anbm

Senior Member
Can you convert the 225 amp panel to a main breaker of 225 amps or even 200 amps. Some panels can do that but I am not sure about 3 phase panels.
Too many troubles to invest, will change 250A main CB in upstream panel to 225A CB. Thank you!
 

jap

Senior Member
If I had feed thru lugs available in the 250a panel, I'd tap em to a fused disconnect or ECB and roll from there.

I'd want everything that 250a Main had to offer.

JAP>
 

petersonra

Senior Member
Location
Northern illinois
Occupation
engineer
250A main CB panel, 208Y/120V, 3PH, can we use this panel to power an existing 225A MLO 208Y/120V, 3PH panel
via feed through lugs with 250A wires (4 #250KCM)? Any codes issues? The two panels are 120 feet away from each other.
I am curious what is protecting the 225 A panel at present.
 
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