Replacing existing 3 wire fed subpanel

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Old 10-27-18, 09:14 AM
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Replacing existing 3 wire fed subpanel

Hello,

I need to replace an existing 3 wire fed subpanel (H-H-N) serving my pool room, which is attached to the main dwelling. I am pretty sure it was not properly installed originally. The feeder wire is #8 Romex. The bare ground wire connects to the neutral bus and there is no separate ground bus.

What is the best way to replace this in a safe way?

Picture of existing panel here
 
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Last edited by ray2047; 10-27-18 at 04:17 PM.
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Old 10-27-18, 02:46 PM
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The feeder wire is #8 Romex.

Looks more to me like 10-2 W/G NM cable. You have no neutral, the bare ground wire is being used as a current carrying conductor, a major code violation. First, I'd rip the feeder out and replace it with a proper 3-wire plus ground feeder. Then, rewire that whole mess.
 
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Old 10-28-18, 08:08 PM
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Not even worth trying to salvage. Lucky that someone hasn't gotten shocked on that setup.

When you rewire the feeder to the pool needs to be insulated.
 
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Old 10-29-18, 01:49 PM
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Thanks to you both for your assistance. It is clear that the existing panel wiring is screwed up majorly.

A new feeder line will be very difficult to run to this location. Can I avoid running an entirely new feeder by wiring up a 120v only subpanel (prominently labeled as such) - i.e., replacing the 30A double pole breaker in the main panel with a 30A single pole, and hooking up the ground and neutral wires to the proper buses? I need to operate three 120v circuits from the subpanel - a 15 amp circuit that operates some plugs and lights around the pool area, a 20 amp circuit that operates a 1.5 hp pool pump and saltwater system, and a 20 amp circuit that operates a well pump (I think 1.5 hp as well). Would the anticipated load from those circuits be too much for the 10/2 feeder at 120v?

For what it's worth, I typically run the pool pump only a night, when we're not ordinarily using the well pump. There will of course be times when both pumps are running simultaneously.
 
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Old 10-29-18, 02:10 PM
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Yes you could convert this panel to 30A 120V, but are your pumps capable of operating on 120V? Some motors are dual voltage, some are not.

There should be enough power to run both pumps, but if they are starting up at the same time it would probably trip the breaker. Pumps draw a lot more current in the first seconds after starting.
 
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Old 10-29-18, 02:55 PM
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Thanks very much. Both pumps are currently operating at 120v (they are both dual voltage). If you look carefully at the double pole breaker you'll see that it's not running to a 220v circuit, but rather to two separate 120v circuits (one for each pump). My original intent in fiddling with the subpanel was to put these on separate breakers. I knew that it wasn't wired correctly. To make matters worse, the pool pump is switching the neutral. But I'll get all of that fixed once I have a safe subpanel to start with.
 
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Old 11-20-18, 12:04 PM
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Follow up questions

I have some follow up questions.

The pool subpanel that I have decided to convert to 120v only (to solve the safety issues described above) is itself fed by a subpanel. This intermediate subpanel used to be the main panel for the house, but was converted to a subpanel when an addition was added on.

The intermediate subpanel itself appears to be a 3-wire, 220v only subpanel. It is labeled with a sticker that says "No single pole breaker permitted in this center." And, it doesn't have a neutral bus bar...only a ground bus bar. Since all of the breakers are double pole, only ground wires are attached to the ground bus bar.

See pictures of my intermediate subpanel here.

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To make matters worse, downstream of my intermediate subpanel is yet another subpanel that contains a bunch of 110v breakers running plugs, lights, and switches throughout the house. Once again, this subpanel is fed solely by 3 wires from the intermediate subpanel. In this case, the neutral and ground wires are bonded to the same bus, which i know violates code. A picture of this second downstream subpanel is here.

My questions:
1. To convert the pool room subpanel to 120v only, could I simply replace the 30 amp double pole breaker with a 30 amp single pole breaker in the intermediate subpanel? I would then have no choice but to bond both the neutral wire and the ground wire to the ground bus in the intermediate subpanel. Is this still a substantial safety improvement even though it violates code?

2. Is there anything I can do to improve the safety of the intermediate panel or the second downstream panel?

3. Any other things I should be concerned with?


Thanks very much in advance.
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Last edited by ray2047; 11-20-18 at 01:09 PM. Reason: Add image.
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Old 11-21-18, 07:16 PM
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1. To convert the pool room subpanel to 120v only, could I simply replace the 30 amp double pole breaker with a 30 amp single pole breaker in the intermediate subpanel? I would then have no choice but to bond both the neutral wire and the ground wire to the ground bus in the intermediate subpanel. Is this still a substantial safety improvement even though it violates code?

No, because there is no neutral in the intermediate (240 volt only) subpanel that feeds the pool room subpanel. Ground should be only bonded to neutral one time, at the first disconnect at the service.


2. Is there anything I can do to improve the safety of the intermediate panel or the second downstream panel?

Yes, install a proper 4-wire feeder to each, install a ground bar in each and isolate the neutral bus in each panel from the grounded panel box.


3. Any other things I should be concerned with?

Yes, judging from what I have seen I'd also be concerned about the main service panel and other branch circuit wiring. I'd recommend getting a good qualified electrician to come inspect the entire electrical system and make a list of upgrades and repairs to correct your numerous code violations which are also safety issues.
 
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