# Adjusting EMT conduit to different knockout location on new service panel



## Roekeye (May 26, 2021)

I will be replacing a service panel and the knockouts on the new panel do not align with the old panel. All runs use 1/2 inch EMT conduit which may not be flexible enough to move to alternate knockout locations. Keeping in mind that the home uses the conduit as a ground everywhere whats the best way to adjust them to the new box?

Here are my initial ideas and thoughts as to why not to use them:
Install the new service panel a few inches lower and add some short offset bends with couplers. Seems tedious, but should work.
Install the new service panel a few inches lower and use flexible steel conduit to bridge to the new knockouts. Feel iffy using flexible conduit for grounding.
Just force it, the new knockout are not THAT far off and the conduit might have enough flex to be forced. Could cause the fittings to attach at uncomfortable angles leaving gaps not great for a grounded connection.


----------



## Wirenuting (Sep 12, 2010)

How long have you been an electrician?


----------



## just the cowboy (Sep 4, 2013)




----------



## Easy (Oct 18, 2017)

Pull out the 1/2 emt runs that don't line up and re-bend them. Your doing the service change anyways and making a couple of bend in thin-wall shouldn't be that difficult.
Your second option might be to add a J-Box. It would be nice if they made an adjustable offset bender that could fit in tight spaces and was batterie operated.


----------



## Coppersmith (Aug 11, 2017)

I have used flexible metal conduit (FMC) when I've encountered panels that have EMT going into the top and bottom. I cut the EMT on the end that has the least pipes. I cut it back about a foot. You have to use a rotary pipe cutter so you don't cut the wires. Then I added the FMC whips with a changeover. Made it easy to reconnect everything without smashing the conductors.

You can buy panels that have no KO's, then make your own where needed.


----------



## canbug (Dec 31, 2015)

Cut holes to match the existing conduit?

Tim


----------



## Coppersmith (Aug 11, 2017)

canbug said:


> Cut holes to match the existing conduit?
> 
> Tim


You can do that, but since you will be cutting across existing KO's, grounding bushings will now be required.


----------



## canbug (Dec 31, 2015)

That's a new one on me but maybe I'm doing it wrong and no one ever pointed it out?
I'll check into that.

Tim


----------



## Yankee77 (Oct 5, 2020)

Can you change out bottom and top of panel, most panels are pre-pounced on top and solid on bottom of panel


----------



## SWDweller (Dec 9, 2020)

Or just get a panel can with NO knock outs and do your own where they need to be.


----------



## splatz (May 23, 2015)

Put a trough over the panel, land the old pipes in the trough, and run a few big nipples from the trough to the panel.


----------



## Southeast Power (Jan 18, 2009)

I have changed piped in panels for about 40 years.
I have one word for you:
“Reducing washers”
Buy 50-1/2” x 1” and 50-3/4” x 1”
They will maintain the ground integrity of the EMT.


----------



## Yankee77 (Oct 5, 2020)

Leave the back box and change just the guts


----------



## VELOCI3 (Aug 15, 2019)

Get a panel with no factory KO’s


Sent from my iPad using Tapatalk


----------



## Southeast Power (Jan 18, 2009)

VELOCI3 said:


> Get a panel with no factory KO’s
> 
> 
> Sent from my iPad using Tapatalk


If he is changing out one with prepunched kos it’s a loadcenter, not so much a panelboard


----------



## wiz1997 (Mar 30, 2021)

Done panel replacements where we cut the bottom out of the panel bottom leaving about an inch or so of the bottom around the outer edge.
Obtain a piece of sheet metal equal to or thicker than the the box metal.
Lay out the holes on the flat sheet metal and cut them out.
Check for proper layout then....
Drill and bolt the flat panel onto the bottom of the panel.

Or as someone stated earlier, get a box with no knockouts.


----------



## mofos be cray (Nov 14, 2016)

canbug said:


> That's a new one on me but maybe I'm doing it wrong and no one ever pointed it out?
> I'll check into that.
> 
> Tim





Southeast Power said:


> I have changed piped in panels for about 40 years.
> I have one word for you:
> “Reducing washers”
> Buy 50-1/2” x 1” and 50-3/4” x 1”
> They will maintain the ground integrity of the EMT.


2018 cec says you can't use reducing washers to maintain bonding continuity. I don't have my book in the house to cite the rule but it's there. If I remember I'll post it tomorrow.


----------



## Wardenclyffe (Jan 11, 2019)

Rewire the whole house, run new conduit,...


----------



## kb1jb1 (Nov 11, 2017)

Southeast Power said:


> I have changed piped in panels for about 40 years.
> I have one word for you:
> “Reducing washers”
> Buy 50-1/2” x 1” and 50-3/4” x 1”
> They will maintain the ground integrity of the EMT.


I thought you need bonding bushings with reducer washers and some concentric knockouts.


----------



## kb1jb1 (Nov 11, 2017)

splatz said:


> Put a trough over the panel, land the old pipes in the trough, and run a few big nipples from the trough to the panel.


Of all the suggestions here i think this is the most feasible. Especially since the EMT is used for the equipment grounding conductor. Many good suggestions here but a trough is cheap compared to a special order panel.


----------



## splatz (May 23, 2015)

kb1jb1 said:


> Of all the suggestions here i think this is the most feasible. Especially since the EMT is used for the equipment grounding conductor. Many good suggestions here but a trough is cheap compared to a special order panel.


You could even cut off the top of the old panel and use it as a template to lay out the KOs on the trough. Some maintenance tasks will be quicker and easier not having to open up the panel.


----------



## d2043 (Nov 12, 2013)

You can cut the pipes off and change over to flex or ENT (smurf tube)


----------



## splatz (May 23, 2015)

d2043 said:


> You can cut the pipes off and change over to flex or ENT (smurf tube)


But he needs the conduit to be the EGC...


----------



## splatz (May 23, 2015)

I guess nobody said the easiest thing of all, rip the guts out of the existing panel, declare it a junction box, put the new panel next to the old, and go home early. 

Did anyone say use one of the renovation kits where you just replace the guts and use the old box? That might work too. _edit: yes, @Yankee77 said that in post #13. _


----------



## d2043 (Nov 12, 2013)

splatz said:


> But he needs the conduit to be the EGC...


You can use a bonding jumper (w/ground clamp) from the pipe to the metal on the load center or the ground bar terminal.


----------



## d2043 (Nov 12, 2013)

splatz said:


> I guess nobody said the easiest thing of all, rip the guts out of the existing panel, declare it a junction box, put the new panel next to the old, and go home early.
> 
> Did anyone say use one of the renovation kits where you just replace the guts and use the old box? That might work too. _edit: yes, @Yankee77 said that in post #13. _


That is a good option as well.


----------



## seelite (Aug 24, 2009)

Started in the trade in 1958 put in over 50 yrs. K+T, BX, RX w/AL yr, RGS, Rigid AL, EMT. And a mess of others to match existing. Numerous upgrades in Residential with pre-punched Load center so ran into this same problem. Been mentioned above but what I did many times was place a piece of 4x4 duct and chase nippled with 1 or 2 large nips into load center. Cut all pipe to same lenght with rotary cutter, couldn't ream inside so used large 'Red Devils' (made for Greenfield flex). In most cases (not all) wire was long enough to slip through the duct and into Loadcenter & Breaker. If not, then YR nutted in the duct. A bonding bushing on the nipples and was the Inspector happy. Was able to keep
the inside of Loadcenter looking neat also. Am now 84 yrs young so don't do much wiring except for self, kids & grandkids. Keeps the fingers nimble when I do and gives excuse to go to seminars (although many are now online). Glad you folks are all working, Thanks for buying me breakfast (with the $ you put into Soc.Sec). Bye now.


----------



## macmikeman (Jan 23, 2007)

You guys all have such short memories. And somebody messed up the picture albums in a royal way. I posted exactly how to deal with this in a thread and a series of pictures posted here . I cut a 14 1/2" by 3 1/2" piece of sheet metal and screwed that onto the top of a brand new panel. then I drilled pilot holes where I wanted all the existing conduits to be. It no longer mattered if there was a half a knockout missing on the lower top layer as long as a good locknut to metal seat was made. This was always for flush in wall jobs though. If it is a surface panel I would have waited for a no knockout electrical panel to be shipped over and done virtually the same thing...


----------



## MotoGP1199 (Aug 11, 2014)

kb1jb1 said:


> I thought you need bonding bushings with reducer washers and some concentric knockouts.


Yes for 277(or 250v to ground) and above. I forget the exact contact voltage limit to ground requirement but essentially it's for 277 Volt systems and up.

Edit: found it.


> 250.97 Bonding for Over 250 Volts. For circuits of over 250 volts to ground, the electrical continuity of metal raceways and cables with metal sheaths that contain any conductor other than service conductors shall be ensured by one or more of the methods specified for services in 250.92(B), except for (B)(1).
> 
> Exception: Where oversized, concentric, or eccentric knockouts are not encountered, or where a box or enclosure with concentric or eccentric knockouts is listed to provide a reliable bonding connection, the following methods shall be permitted: (1) Threadless couplings and connectors for cables with metal sheaths
> Service panelboard
> ...


----------

