why do I have a "Load Center"?


  #1  
Old 11-13-02, 11:13 AM
eaanderson
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why do I have a "Load Center"?

This is a posting I had placed in the Basements forum, but I didn't get an answer there. The experts I'm looking for are probably hanging out here instead...

I'm trying to figure out why I have a "QO Load Center" box (Square D cat no Q02-4L70S to be exact) next to my main breaker box and connected to it with two electrical conduit sections. I recently went to Square D website to try to learn exactly what these are for, but the technical data I found did not really answer that. Apparently, my unit is for single-phase, 2 circuits and 70 amps max. I'm still puzzled on exactly what it does. I recall that previous home owner had a hot tub on back patio, so I'm guessing it had something to do with that. However, inside the main breaker box, there is already a (dual) breaker switch marked "WHIRLPOOL". So, I wonder if both were needed? Both the whirlpool breaker in main box AND the switch on the load center are in OFF position.

I would like to move this smaller box closer to the main electrical box if it's not too much work. Or, since it appears to no longer be used, perhaps I can even remove it? Otherwise it's going to be an annoyance to my basement finishing work, as the two boxes are separated by a couple feet.

Thanks for your ideas,
Eric
 
  #2  
Old 11-13-02, 11:52 AM
M
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My guess is that this is a subpanel for the hot tub. Is the breaker inside this subpanel a GFCI breaker (does it have a little button marked "TEST" on it)?

You need to verify how this subpanel is connected inside the main panel. I'm not sure why it would have two conduits running to the main panel. Open the main panel and (carefully!) see if you can trace where the wires from the subpanel are connected. Likely you will see a white wire and a green (or bare) wire connected to the grounding bar, and two other wires (probably black and red) connected to the "WHIRLPOOL" breaker.

Are there any wires leading away from this subpanel? If so, can you figure out where they go? This may also help us figure out what the subpanel is for.

If indeed this is a subpanel for a hot tub that is no longer there, there is no reason that you can't remove it, as long as you remove the wiring feeding it from the main panel.

Post back with your observations.
 
  #3  
Old 11-14-02, 10:15 AM
eaanderson
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Thanks for your reply, mikewu99. The breaker on the subpanel DOES have a test button with note "push to test monthly". So it's a GFCI breaker?

I plan to open the main panel in next few days to inspect how subpanel is connected in. By the way, do you recommend that I shut off the "main" breaker before I take cover off main panel? I guess I'm a little nervous about opening it, but it looks like it's just removing a few screws and pulling off cover.

The only wires leading away from the subpanel both go into side of main panel. That is, two hard pipe connections go between the main panel and subpanel.

I will post back with my findings in the main panel, but I'm looking for a little advice on how to safely do this.

Thanks,
Eric
 
  #4  
Old 11-14-02, 01:24 PM
M
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"So it's a GFCI breaker? "

Yes, it's a GFCI breaker.

"do you recommend that I shut off the 'main' breaker before I take cover off main panel?"

If you are unfamiliar with the insides of a panel (like it sounds like you are) it's probably a good idea to shut off the main breaker. WARNING: There are still parts of the main panel which are energized even when the main breaker is off (the terminals leading into the main breaker). Don't go poking around unless you know what you're doing. If you're unsure - look, don't touch.

You also want to open the subpanel to see how it is connected inside too.
 
  #5  
Old 11-18-02, 11:02 AM
eaanderson
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Ok, I opened the main panel and subpanel for inspection and here is what I found. The lines originate at a 220V breaker in the main panel, then travel through the GFCI breaker in the subpanel. From there, the lines return to the main panel only to exit the main panel through another conduit, which leads to yet another breaker box outdoors near former location of hot tub.

My conclusion is that the sub panel (ie "Load Center") was needed because code probably requires a GFCI breaker to be on the hot tub circuit. Because the 220V breaker in the main panel is not a GFCI breaker, the former home owner added the (GFCI) subpanel breaker.

Do you agree with this conclusion? If so, I have one more question. Couldn't the former home owner have simply installed a 220V GFCI breaker in the main panel? It seems like that would have been a lot easier than installing the subpanel and conduit linking it to main panel.

Thanks again for your feedback.
Eric
 
  #6  
Old 11-18-02, 12:34 PM
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Your analysis seems correct. Since you don't have the hot tub, you can just remove the outdoor breaker box, the wiring from the subpanel with the GFCI, the subpanel itself, and the breaker in the main panel where all this originates. That give you two more available breaker slots.

If you are considering getting a hot tub, you may want to keep everything in place but de-energized.

As to why it was hooked up like this? Here are a couple of guesses:

(1) The GFCI subpanel may have come come with the hot tub. Usually the GFCI subpanel is installed near the hot tub ("in-sight disconnect") and wired back to the non-GFCI breaker in the main panel. The owner may have put the GFCI subpanel in its current location nect to the main panel, then found out that he needed the in-sight disconnect, and found it easier to add the additional outdoor panel instead of moving the GFCI panel.

(2) A GFCI breaker and subpanel may have been cheaper than a GFCI breaker alone for the original panel, particularly if the original panel is old or oddball. Or maybe it was so oddball that no appropriately sized GFCI breaker was available at all.
 
 

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