Knife switch disconnect question

[Robert Foster]

The panel in the photo is the main service panel/disconnect. Home built in 1929.

Can someone please explain/educate me on why/ramifications of, the neutral service entrance conductor is/being connected to the load side of the knife switch.

The four conductor cable in the lower left of the panel is a relatively recent clothes dryer receptacle. Why is it's neutral conductor connected to the load side of the knife switch ?

Thank you.

[Gunnar Alquist]

Neutral should not be fused. You also have double taps. In addition, I make remarks that the panel can be easily opened and no dead-front is present. I would defer to an electrical contractor.

[Robert Foster]

Yes, of course the whole house is going to be rewired.

Are you saying the neutral is located properly because it should not be fused ?

[John Kogel]

If you're asking why, the answer is because simpletons can get their hands on tools.
That cord to the dryer was installed completely wrong, except that it works, which was why it was left that way. The neutral looks like it is scorched as well.

[Gunnar Alquist]

Are you saying the neutral is located properly because it should not be fused ?

Hi Robert,

Difficult to say. I'm pretty tired and not thinking clearly.

Below, I believe is the section in the 2009 IRC prohibiting the grounded (neutral) conductor from being fused. E4001.8 also refers to not switching grounded (neutral) conductors.

E3705.5 Overcurrent protection required. All ungrounded
branch-circuit and feeder conductors shall be protected against
overcurrent by an overcurrent device installed at the point
where the conductors receive their supply. Overcurrent devices
shall not be connected in series with a grounded conductor.
Overcurrent protection and allowable loads for branch circuits
and feeders that do not serve as the main power feeder to the
dwelling unit load shall be in accordance with this chapter.

[Gunnar Alquist]

Which neutral are you referring to? The only one going through the fuse is the neutral for the flexible cord. The others are simply "spliced" together at the bottom terminal.

I believit should be removede that multiple lugging is not allowed. Fusing a neutral is also not allowed. So, the neutral for the flexible cord should not be fused. Of course, the flexible cord is not intended for permanent installation, so I would recommend removal as well.

[Garry Blankenship]

That knife switch is original material, as evidenced by the fused neutral. Probably came over on The Mayflower. That dryer circuit is illegally hot tapped off the load side of the main disconnect. It is legal to to do that, but only with appropriate terminations and there must be overload protection, ( fuses or a C/B ), on those tapped conductors within 10' of their length, ( maybe 25' depending on wire amperages ). Short version is it's illegal by the code then or now.

[Rollie Meyers]

I believit should be removede that multiple lugging is not allowed. Fusing a neutral is also not allowed. So, the neutral for the flexible cord should not be fused. Of course, the flexible cord is not intended for permanent installation, so I would recommend removal as well.

Have a code section for that? There is plenty wrong there w/o including that.

[Robert Foster]

Thank you for all the replies.

Unfortunately, they illustrate how much electrical stuff I do not know.

[Jerry Peck]

I believit should be removede that multiple lugging is not allowed. Fusing a neutral is also not allowed. So, the neutral for the flexible cord should not be fused. Of course, the flexible cord is not intended for permanent installation, so I would recommend removal as well.


Have a code section for that? There is plenty wrong there w/o including that.

The following are the limitations of protecting the neutral, grounded conductor, with overcurrent protection:
- 240.22 Grounded Conductor.
- - No overcurrent device shall be connected in series with any conductor that is intentionally grounded, unless one of the following two conditions is met:
- - - (1) The overcurrent device opens all conductors of the circuit, including the grounded conductor, and is designed so that no pole can operate independently.
- - - (2) Where required by 430.36 or 430.37 for motor overload protection.

In 240.22(1), a fuse does not meet that requirement. In 240.22(2), a fuse does not meet the requirement of 430.37 either.

[Rollie Meyers]

My comment was directed to this, "believit should be removede that multiple lugging is not allowed".


My comment was directed to that quote, the whole switch is a mess so chose not to comment on the rest...

[Jerry Peck]

My comment was directed to this, "believit should be removede that multiple lugging is not allowed".


My comment was directed to that quote, the whole switch is a mess so chose not to comment on the rest...

Rollie,

I understood that, I posted that so the others would know the restrictions on protecting the neutral with an overcurrent device - basically that a fuse does not "opens all conductors of the circuit" because a blown fuse only opens that one conductor which is connected to that fuse. Basically, an internal trip breaker would be required as a handle tie could come off, be removed, break, etc. ... yes, I know, the code does not state that it has to be internal trip, but I know many AHJ who will interpret "opens all conductors of the circuit" to mean that one cannot rely on a not-manufactured on handle tie. We even had a photo posted recently which showed a manufactured on handle tie which broke and did not "opens all conductors of the circuit".

[Rollie Meyers]

In a grounded B phase system, one of the phases is grounded, & it's treated as a grounded conductor, in the OP's case the fuse on the noodle & the B phase should not have a fuse there, Bussmann does make a "dummy fuse*" which is 1 solution,but ripping the whole thing out & sending it all to be recycled, :D then bring it up to current standards is the best choice.....

* The dummy fuse is a better choice then the "normal" method of slapping a piece of copper pipe in the fuse clips, which sort of works but just ain't right.:eek:

[Gunnar Alquist]

Hi Rollie,

I am not sure what happened to my post, because that nonsensical garbage was not what I had intended to write. I have been trying to remember what it was that I wrote. I cannot remember specifically, but if writing a comment for a report, I would have noted at least these three items.

1) I believe it is generally accepted/understood that multiple lugs are not allowed unless specifically listed and labeled.

2) Looks like an extension cord (or similar) at the lower/left of the panel. I believe that extension cords are intended for temporary use. I would have recommended removal of the cord.

3) The panelbox itself can be easily opened and the wires/contacts are exposed. This would have been mentioned as potentially hazardous and I would have recommended replacement.

Sorry about the poor proofreading and typing skills.