Old Fused Subpanel

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  #1  
Old 08-10-05, 01:29 PM
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Old Fused Subpanel

Hi,

I've got an old fused Federal Pacific subpanel that I'd like to replace with a new circuit breaker panel.
This sub-panel is fed from a 30 amp two-pole breaker in the main panel and currently has 4 15amp NM lines running out of it. The cable that feeds the fused panel is BX with two hot leads and one neutral (no ground).

When I replace this panel with a new one, can I continue using the existing BX cable? My concern is that the new panel may not be properly grounded. Should I just replace the BX with properly sized NM?

Thanks,

Dave
 
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  #2  
Old 08-10-05, 02:20 PM
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Should I just replace the BX with properly sized NM?
If feasible, I certainly would.
 
  #3  
Old 08-10-05, 02:23 PM
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NJDave,

In my opinion if you are going to replace the sub-panel and have the ability to get to BOTH ends of the feed meaning from the main panel to the new panel I would most certainly replace the BX with new wire.

Now since you have a 30A sub-panel feeding (4) 15A feeds I sure hope their is not much on those (4) feeds....

Anyway dealing with what you have asked I would certainly upgrade the feeder to the sub-panel and remember you have a SUB-PANEL here in your situation so please be aware of the requirements regarding them as well.
 
  #4  
Old 08-10-05, 03:01 PM
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Thanks for both responses.

Here's what the 4 circuits from the subpanel are supplying...

Circuit 1:
Garage door opener
light in garage
2 outlets in the garage
2 lights outside the garage
1 outlet outside the garage

Circuit 2:
1 outlet in the basement (lamp)
1 floor outlet in the kitchen (unused)

Circuit 3:
1 4x outlet in the basement (washing machine)

Circuit 4:
1 floor outlet in family room (TV, cable box)

Do you think there's an overload here for the 30 amp feed?

I know that the neutral bus bar and the grounding bus bar need to be separated in the subpanel. Are there any other special considerations I should be aware of?

Thanks again,

Dave
 
  #5  
Old 08-10-05, 03:02 PM
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What are the garage outlets used for?
 
  #6  
Old 08-10-05, 03:18 PM
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hmmmm....sure seems like ALOT of stuff on that 30A sub-panel but again it is all about the use.

Heck with the Washer going and ohhh....a drill plugged into the recept in a garage could blow the breaker on the sub.....

Just at first glance it seems like alot for a 30A sub-panel......and may I ask HOW FAR is this sub from your main if you do not mind.

Anyway you probably will be fine as long as you are AWARE of what you have....you are not going to be running multiple items on multiple circuits or some tablesaw in the garage while the washing machine is going and " Peggy Sue " is playing with her " Bake N' Cook " oven in the basement then you might be fine.....

Just seemed like alot of items without going into alot of detail....as always circuits dont pull MUCH until they have a demand on them....then you need to be aware of it.
 
  #7  
Old 08-10-05, 03:47 PM
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The garage outlets aren't used for much at all. Maybe to run a vacuum once in while to clean the car, or a hedge trimmer, etc.

Would it make sense to replace the 30 amp feed with a 40 amp instead since it already makes sense to replace the line anyway? (replacing the 2-pole breaker in the main panel of course)

BTW, the subpanel is about 25 feet away from the main panel, on the other side of the basement.

Dave
 
  #8  
Old 08-11-05, 06:22 AM
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Bus bar confusion

OK, I picked up a small Square D panel at Home Depot last night, but now I have another question.

The box only has one bus bar, which I believe is a neutral bar. They sell bus bars separately, should I get one and add it somehow as a grounding bar? Also, on the inside of the panel cover it says, "When used as service equipment, all unused neutral terminals may be used for terminating equipment ground wires." This seems to imply that the single bar can be used for both neutral and ground. If that's the case however, where do both the ground and neutral wires from the feeder cable attach?

Dave
 
  #9  
Old 08-11-05, 06:27 AM
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You are installing a sub panel. As such the grounds and neutrals MUST remain separated.

Buy a separate ground bus for the panel. Remove (and discard) the small screw that would be used to bond the existing bus bar to the panel. Connect the neutrals to the existing bus bar and the grounds to the new bus bar that you will install.
 
  #10  
Old 08-11-05, 06:43 AM
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Racraft,

In the grand scheme of things (or at least as I understand them), that seems to make the most sense.

Thanks,

Dave
 
  #11  
Old 08-11-05, 06:55 AM
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Since the subpanel is only 25 feet away, I'd go ahead and buy 6/3 and a 60-amp breaker. The cost difference will be small and you'll then have all the power you need for quite a while.
 
  #12  
Old 08-17-05, 10:29 AM
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Thanks for the help!

I've completed my installation of the new sub panel.

I ended up using 6/3 cable as the feed from the main service panel with a 50 amp breaker. With the 4 existing circuits disconnected while I swapped sub panels, I took the opportunity to clean things up a bit. I drilled holes through joists and got all of these cables running through the joist, instead of hanging under them. Looks alot neater, and everything seems to work.

Thanks again!

Dave
 
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