I wonder why more installers don't install the panel with the Main on the bottom. Next time you have a situation where the meter is outside and back to back with the breaker panel look at the panel and see if it is universal with respects to bottom fed or top fed. It's a lot easier to install and you won't fill up the gutter space with Service Entrance conductors.

I do all I can to enter the enclosure where the terminals are, many of the panels I receive can be mounted either way. If it is easer to have the main at the bottom I will do that.


I hate seeing the gutters filled up with service or feeder conductors.

Check this one out.



More pictures here;
https://www.electrical-contractor.net/ubb/Forum5/HTML/000532.html

Bob

[This message has been edited by iwire (edited 01-23-2005).]

How about the bending radius? If you are using 4/0 aluminum for a 200 amp panel and you enter the panel enclosure from the back?

Will this meet the minimum bending radius for a standard 200 amp panelboard enclosure?

Pierre

Switch boards are not defined in the NEC article 100, all though panel boards are.
There is no clear distinction between the two.

With that said it seams to me that when you run the service conductors up the side of the panel, and they are not terminating on that side, it violates 408.3(A)(3)

Article 100 2002 NEC

You will not see a switchboard in a dwelling unit (most times )

A switchboard may have clearly defined vertical sections, a panel does not.

Thanks Bob:

I see where I missed switchboard, I didn't look far enough.

I have to agree with Pierre that the wire bending space does not fit.
Also 314.28 has been thrown out the window

Whats up with all those tie wraps ?
I dislike seeing tie wraps in a panel - for 1 reason - HEAT !
When I get into a panel and see this I take my wire cutters and remove them. Most of the time I find heat marks on the conductors under the ties. I tell my apprentices that this practice creates a
" future failure "


Be Smart and Do It Right

George Little / Member posted 01-23-2005 08:43 AM Man did this thread ever get side tracked.

I have had inspectors object to the two more feet of SEC that it takes to reach the bottom of the cabinet and technically they are right in that it is not "nearest the point of entry."

In CSA excepted panels there is a dead front over the line terminals so you have to run the supply conductors in through that end of the cabinet. The dead front also prevents you from running branch circuit conductors out of that end of the cabinet. On one old panel type I saw on the air force bases I served on as a lad the cover fasteners were studs with wing nuts and the panel cover would not come off if the main breaker was in the on position. I sometimes think that would be a good technique to adopt in the US for all residential panels when coupled with a Canadian style dead front.
--
Tom H

[This message has been edited by tdhorne (edited 01-25-2005).]

Re Russ M's comment: "Also 314.28 has been thrown out the window"
314.28 applies to junction or pull boxes, not panelboards, right?
Re Pierre's comment: "How about the bending radius? If you are using 4/0 aluminum for a 200 amp panel and you enter the panel enclosure from the back?
Will this meet the minimum bending radius for a standard 200 amp panelboard enclosure?"

Does table 312.6(A) apply to the front to back distance?
The note in the bottom of the table only mentions measuring in a straight line from the end of the terminal lug (which end? where the wire butts up in the barrel or at the open end of the lug?) to the wall of the panel.

Re. luckyshadow's comments: "Whats up with all those tie wraps ?
I dislike seeing tie wraps in a panel - for 1 reason - HEAT !"

If the conductors are rated to handle the heat in conduit, I see no reason to worry about them getting heated in the panel due to being clustered under tie raps. Putting three phases and neutral in a tie wrapped grouping serves to minimize magnetic fields (per 300.20(A)) and helps to secure conductors in place.

"If the conductors are rated to handle the heat in conduit, I see no reason to worry about them getting heated in the panel due to being clustered under tie raps"

The exact same rule applies. If more than 3 are bundled more than 2 feet derating kicks in.

This subject sure has drifted, but since it has I would like to comment that I don't think the derating rules in 310.15(B)(2) apply to the gutter space in panels. I'm sorry, but I don't believe the intent was to apply these rules to panels because if we do most panels out there would not pass inspection. we would be derating every conductor in the panel. Now someone explain to this group what maintaining spacing is all about.

Hi,
I wanted to reply to the original comment.

It has always been my understanding that the LINE SIDE should ALWAYS be at the TOP.

I thought this was standard practice where possible? I think this carries over from the wiring arrangement in disconnects.

A feeder can enter the enclosure at any accessible place within the enclosure but should still terminate at the top. I do not think that having the line side at the bottom is good practice.

I am talking about disconnects and panelboards not switchboards, mcc or switchgear.

I know electricians that even use the top screw on switches and outlets to terminate the line.

As far as I know there is no rule that requires this but it is done. It makes practical sense and logical sense.

A GFI is usually configured the same way. Line at top load at bottom.

It seems to me there is a rule somewhere that requires the line to be at the top? Maybe I am thinking of a spec.

It may be a good idea if you want to meet the american disabilities act by that I mean having the breaker at a lower position so that a person in a wheelchair could operate the breaker.

I was on a job where some hand cut some 350 MCM feeders to the load side of a disconnect because he did not know what he was doing. If he had experience and training he would have drifted to the top anyway!

I am a top breaker guy I guess.

The photos are interesting.

Regards

Greg



[This message has been edited by mustangelectric (edited 02-03-2005).]

What about when someone installs them with the grounding hole down?

Hi,
Frank, that does not change the way the receptacle is CONFIGURED only its ORIENTATION.

I am talking about wiring or termination practices.

Good point though.

Regards

Greg

Hi,
I looked at a 200A Sq-D panel yesterday before I installed it and the panel can be installed in any vertical position. I have always been aware of the LINE/LINE markings in the panel and knew that the panel could be installed breaker up or down.

I guess I have never really had a reason to do it.

I think it is better up high. People like to lay tools, parts and other FOD in the bottom of the panel. Having the breaker low could be inviting trouble.

Regards

Greg

My experience has included a number of times that moisture was coming into the panel's cabinet by way of the service entry cable or conduit. By running the service entry conductors into the bottom of the cabinet I limit the damage that such water will do to rust in the bottom of the cabinet rather than corrosion of the panel parts.

Locally most of the panels are installed in basements so using the bottom of the cabinet for service entry conductors leaves the top of the cabinet and the wiring troughs free for branch circuit and feeder conductors.
--
Tom H