Screw in Breaker

Have never seen this before, Challenger Panel
Why would there be a screw in it?
Thanks, Steve

Breaker Screw (Small).jpg


What size is that breaker…and is it feeding a SUB panel or is THIS panel being fed by this breaker…? IE: is this the disconnection for this panel…

Sure doesn’t look right…:frowning:


Its a 100amp breaker in the Main and only panel.



It is a 100amp breaker, it is the disconnect for the Main and only panel.
It is the disconnect for this panel

What Paul is doing is have you think about the use of the breaker. If it is the main or the disconnect for a sub panel it is supposed to be mounted so that it is not easily removeable. That would be a proper install under those situations.

Did I explane that correctly Paul?

***[size=1]Back-Fed Devices

Plug-in-type overcurrent protection or plug-in type main lug assemblies that are backfed shall be secured in place by an additional fastener that requires other than a pull to release the device from the mounting means on the panel.


Backfed as in through the back of the panel?
The conductors came through the top.


Backfed does not referr to where the conductors come into the panel.

It referrs to where the electricity comes from. Like from a generator rather than from the power company.

Its not backfed, its a power company feed.

The Type SE Cables here are the “service entrance conductors” and they are energized, and therefore are “back feeding” the circuit breaker through the device screws on the CB.

From UL:

Markings on panelboards that employ plug-on units require the use of a hold-down kit when the units are back-fed and field installed supply conductors are terminated on the plug-on unit.

The marking indicates: "Back-fed _____ requires hold-down kit Cat. No._____ " or the equivalent.

An identification of the applicable back-fed unit is specified in the first blank - for example, circuit breaker, fused switch, or terminal kit; and the catalog number of the required hold-down kit is specified in the second blank.

Exactly. And the circuit breaker is feeding the panel busses through the stab on’s. Opposite of how a branch circuit breaker works.

This is a factory installed proper hold down screw. I’ve seen (and installed) my share of 'em.

You can screw them all down if you want. It is only required if the breaker is backfed. Most commercial manufacturers make panels where all the breakers screw to the bus, no stabs or “U” clips. It certainly helps the reliability.

If the screw goes into the bus bar, it certainly makes it easy to check for power. Just lick your finger and touch the screw!

lol…usually it only screws down to the rail James…lol…but nice thought…thehehe

yes jason…very well done and YEP you understood where I was going with it…all in the education baby…THANKS guys for jumping in…

You all know where I was going…I have become TRANSPARENT…lol

Where is David Valley? What’s happening in Massachusetts as far as home inspectors go? This picture was originally posted long ago, and is in the archives with the others.

A hold down device on a back fed main breaker is different than a bolt-in breaker. True, most commercial panels have bolt-in style breaker and some will accept either bolt-in or snap in, but that does not qualify as a hold down device. Hold down devices are designed for that purpose and that purpose only and are available as an accessory to some main lug panels to allow them to be used when a main breaker is needed or desired. The hold down device are designed so that you may not remove the main breaker by simply snapping it out of the panel. Special note to all HI’s: A back fed panel has the hot wire attached to what is normally the output side of the breaker, so that even if the breaker is tripped the output sdie is still hot! So be careful out there guys.

Thanks for all the help guys.