[Malcolm]

Current setup:
125 amp main breaker disconnect outside next to the meter box
It feeds a panel that does not have a main breaker.


Replacement system:
200 amp exterior panel with feed through
Same 125 amp panel inside


The feed through wires will feed the panel inside. Does there need to be a separate 125 amp breaker to the panel. The same gauge wire will be going from the feed through lugs to the main panel.

 

[Jim Port]

The feeder will need to be protected at its ampacity.

 

[psgama]

Except for panelboards where more than 90% of the overcurrent devices supply feeders or motor branch circuits, every panelboard shall be protected on the supply side by overcurrent devices having a rating not greater than that of the panelboard.

 

[Arrow3030]

Deleted

 

[brric]

In my opinion since you indicated there will be a 200 amp feeder to the indoor panel a 125 amp main will be required to protect the 125 amp buss.

 

[brric]

In my opinion since you indicated there will be a 200 amp feeder to the indoor panel a 125 amp main will be required to protect the 125 amp buss.

Additionally, it is unlikely that a200 amp feeder conductor will fit into a 125 amp breaker.

 

[Malcolm]

To clear up some confusion, the wire that goes to the existing panel box inside will be using the existing wire. The wire will not be upgraded. The only wire that will increase in size will be the wire from the new exterior 200 amp panel to the meter, and the wire from the meter to the utility service.


Let's say there was never a main breaker panel outside and the meter direct fed the panel inside that does not have a main breaker. Would that be up to code? Does there always need to be a main breaker somewhere in the circuit?

 

[Jim Port]

There needs to be overcurrent protection to protect the wires between the meter and panel.

 

[ChiTownPro]

What he said! ^^^^^

 

[Malcolm]

Thanks

Just to clarify, one couldn't just use the proper load calculation of the existing breakers for overcurrent protection.

What would be an adequate solution in my situation? I've had 3 electrician quotes. They all recommended replacing the 125 amp exterior panel (that has a single 125 amp breaker) with a 200 amp 4/8 panel. The new heating and air conditioning would be run off the exterior.

 

[Arrow3030]

Their quote didn't include reconnecting the subpanel?
The solution is to use two of the four spaces for a 125 amp 2 pole breaker.

 

[Malcolm]

Their quote didn't include reconnecting the subpanel?
The solution is to use two of the four spaces for a 125 amp 2 pole breaker.

It doesn't state specifics. You're saying that the 125 amp breaker would need to be setup as a back feed. They were stating that feed through panels would be used (connections to the house panel made at the bottom of the bus bar.

 

[Arrow3030]

The feed through lugs are protected by the 200A service disconnect so the conductors attached to them usually need an ampacity of 200A. There's no back feed set up using a 125A breaker in the meter main.

 

[psgama]

Your new panel should be a 200A Nema 3R minimum rated for service enterance outside. Get a larger panel, an 8 circuit or larger.

Install a 125A double pole breaker and terminate the old feeder to your panel to it. No feed through panel.

Be sure to remove your grounding conductor from your sub panel. It will be bonded to your main, but not taken to ground.

 

[brric]

Your new panel should be a 200A Nema 3R minimum rated for service enterance outside.

Install a 125A double pole breaker and terminate the old feeder to your panel to it. No feed through panel.

Be sure to remove your grounding conductor from your sub panel. It will be bonded to your main, but not taken to ground.

You stil need a grounding conductor to the panel. The neutral/ground bond must be removed.

 

[Arrow3030]

There's nothing wrong with using a 4/8 feed through panel.

 

[Malcolm]

The existing wire that runs from the outside to the interior probably isn't large enough for 200 amp service. I don't know the gauge. It is around 3/8" in diameter (aluminum).

 

[Arrow3030]

Right. You're putting in what sounds like a ranch style meter main with distribution. You'll have 8 circuits you can distribute out of the meter main. Two of those circuits will be for your existing sub panel on a 125A 2 pole breaker. 125A breakers take up two whole spaces so you'll have four circuits left to distribute out of your meter main. It sounds like the A/C will take up at least two of those so you'll be left with two circuits spare in the meter. The feed through lugs are nice because you can put another 200A sub panel with tons of space off them if ever needed.

 

[Malcolm]

That's kind of what I originally planned. I figured 6 of the 8 slots would be used up. It would contain a 125 and two 30 amp double pole breakers.

I called one of the electricians and he confirmed that it would be wired through the feeder terminals (no 125 amp breaker).

 

[Arrow3030]

Then I'm missing a piece of info or the electrician is not following code. You have 4 spaces and 8 circuits for distribution. Any breaker over 50A will take a full space thus reducing the available circuits remaining for distribution by 2.