Older 3 wire panel change outs

[Mt61]

Interested in your opinions on older 3 wire panel change outs.
scenario is:
1.) Meter can and a disconnect on exterior of a residence (has OCPD)
2.) 3 wires to a 150 amp panel on the other side of residence (no main breaker in new panel)
My question is, Does this panel require a Main breaker? Does it matter if previous panel had a main breaker?
This inspection failed for not having a bonding jumper in this new panel.

Please reply with associated questions and information or Snide remarks, all appreciated!

 

[infinity]

What is the wiring method used between the service disconnect and the panel? The feeder requires an EGC. If the panel is within the same structure as the service disconnect it does not require a main and can be MLO (main lug only).

 

[Mt61]

3 wire aluminum cable
This is an existing residence.

 

[kwired]

Interested in your opinions on older 3 wire panel change outs.
scenario is:
1.) Meter can and a disconnect on exterior of a residence (has OCPD)
2.) 3 wires to a 150 amp panel on the other side of residence (no main breaker in new panel)
My question is, Does this panel require a Main breaker? Does it matter if previous panel had a main breaker?
This inspection failed for not having a bonding jumper in this new panel.

Please reply with associated questions and information or Snide remarks, all appreciated!

Was never compliant in the first place, what was there before has no bearing on what is required for new.


The panel in question doesn't require a main breaker within the panel, it does require overcurrent protection that doesn't exceed the rating of the panel bus, and that can be anywhere in the supply line feeding it, including the exterior disconnect where it originates.

If it is not the service disconnecting means or the first disconnect of a separately derived system it should never have the bonding jumper installed - at same time it must have a separate EGC supplied to it. That EGC can be metal raceway or metal sheathed cable containing the feeder conductors that is permitted to be an EGC.

 

[Mt61]

This permit is for a panel change out. Is your opinion this would require EGC extended from the disconnect?
AND are you stating this installation was not compliant in previous code versions?

Adds the question How is the panel case to be bonded?

 

[infinity]

This permit is for a panel change out. Is your opinion this would require EGC extended from the disconnect?
AND are you stating this installation was not compliant in previous code versions?

Adds the question How is the panel case to be bonded?

It was never compliant when installed without a 4-wire feeder. IMO the feeder needs to be changed. The reason it needs a bonding jumper is because the panel is not grounded and even though it is not correct it's better than nothing.

 

[Mt61]

I appreciate the quick responses, and I agree this requires 4-conductors to be compliant.
And response to electricians "I didn't touch the feeder" is ?

 

[drcampbell]

Was never compliant ...

Not even in, say, 1939? Nobody said how old the existing installation is.

 

[Mt61]

The inspector said 1980ish. Some rural area's around here didn't have building departments until 1974

 

[infinity]

This has never been code compliant. Tell the sparky to do it in a code compliant manner which means change the feeder.

 

[Mt61]

Yes Sir

 

[jap]

If this was never compliant, how is it that there are hundreds of 3 wire systems installed just as the OP has described?

2 wire receptacles,,, no EGC in the branch circuits,,, etc...

What purpose would a 4 wire feeder have served back then?

JAP>

 

[Little Bill]

If this was never compliant, how is it that there are hundreds of 3 wire systems installed just as the OP has described?

2 wire receptacles,,, no EGC in the branch circuits,,, etc...

What purpose would a 4 wire feeder have served back then?

JAP>

The purpose of an EGC was not understood at one time. When it was figured out and put into the code, a lot of places either had no adopted code, or no inspections
A 4-wire back then would serve the same purpose as it does today, to keep unwanted current from being on any metallic objects as there would be no EGC to carry the fault current should a fault occur on a 3-wire.
If they had a 4-wire, obviously there would have been no need for 2-wire receptacles.

 

[jap]

The purpose of an EGC was not understood at one time. When it was figured out and put into the code, a lot of places either had no adopted code, or no inspections
A 4-wire back then would serve the same purpose as it does today, to keep unwanted current from being on any metallic objects as there would be no EGC to carry the fault current should a fault occur on a 3-wire.
If they had a 4-wire, obviously there would have been no need for 2-wire receptacles.

But they didnt install a 4 wire back then,

Back then it was a 3 wire service with 2 wire romex and 2 wire receptacles before it became a rule.

A 4 wire feeder from a service disconnect to panel with all 2 wire branch circuits and no EGC in the branch circuit wiring would serve no purpose.

None of the 2 wire branch circuits coming out of the panel had an EGC return path.

You cant call an install a violation if it wasn't a rule to begin with.

Jap>

 

[roger]

Jap, it's time to update your profile.

 

[jap]

I'm still curious if the house in question on this post has branch circuitry that incorporates a wire type EGC.

If the branch circuitry does not incorporate an equipment grounding conductor, simply upgrading the feeder from the service disconnect to the panel is not going to gain anything.

JAP>

 

[Charged]

Should there should be a main bonding jumper in the exterior disconnect? Is that where any grounding electrodes are currently connected ?

 

[infinity]

But they didnt install a 4 wire back then,

Back then it was a 3 wire service with 2 wire romex and 2 wire receptacles before it became a rule.

A 4 wire feeder from a service disconnect to panel with all 2 wire branch circuits and no EGC in the branch circuit wiring would serve no purpose.

None of the 2 wire branch circuits coming out of the panel had an EGC return path.

You cant call an install a violation if it wasn't a rule to begin with.

Jap>

It has never been permitted to have a feeder within the same structure without an EGC. If you're saying that it was permitted let's see a code section to back it up.

 

[Mt61]

I'm still curious if the house in question on this post has branch circuitry that incorporates a wire type EGC.

If the branch circuitry does not incorporate an equipment grounding conductor, simply upgrading the feeder from the service disconnect to the panel is not going to gain anything.

JAP>

yes it is wired with EGC

 

[Mt61]

Should there should be a main bonding jumper in the exterior disconnect? Is that where any grounding electrodes are currently connected ?

yes the main bonding jumper is in the disconnect.