Searching for Advice - New Sub Panel

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Old 05-23-14, 06:59 PM
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Searching for Advice - New Sub Panel

Hi there forum. Like everyone else here, I'm looking for advice. I've done my fair share of electrical projects over the years but nothing quite this large. I have no issues doing typical projects but again, this one is a bit more advanced for me.

I will have a HVAC pro coming by soon and he will be putting in a Mitsubishi 1.5Ton MR. Slim unit for supplemental heating/cooling. This will require 240V, at around 20AMP. Not a big deal by itself, but here's the tricky part... It's going to be around a 100' run of cable.

Since I only want to do this once, what I'm looking to do is to effectively install a new outdoor sub-panel near the area that the condenser is going. But I need this new panel to support three items, the heat pump, a 20Amp 120V circuit for heated floor (although the flooring is suggested to only consume around 7Amps for my application), a small 15Amp 120V circuit for landscape lighting, and finally, a future hot tub. So I need four breakers, a 20Amp 240V, a 50Amp 240V (GFCI), a 20 Amp 120V, and finally a 15Amp 120V.

My plan was to install one of the SquareD panels but clearly I think I'm going to need a 100Amp panel (i was thinking Lowes part HOM1224M125RBVP). I already have a sub panel in the basement that has the 40Amp 240V circuit coming off of the primary panel. I am planning on running the service wire through my crawl space the length of the house and back out to the outdoor sub panel. This run is estimated at around 80-90 feet total. My primary panel is a 200Amp panel.

So my questions are:
1) Based on the attached image, will my primary panel even support an additional circuit this size?
2) Is 3/4 cable going to suffice with that wire length and amperage?
3) Can anyone provide a suggested outdoor sub panel that would be better to use?
4) Where in the world should I get the wire? Clearly Lowes and Home Depot don't have wire like this, and what would be the best kind to use?
5) Obviously any outdoor sections will be clad in rigid metal conduit, but can I get away with supporting the wire by hanging it from the steel I beams in the crawl space?

Any additional input here? I will most likely do the majority of the work myself to save money, but possibly hire someone to do the final connection to my existing primary panel. Figured that would be the safest method. Thoughts?

Thank you in advance for any constructive help.

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Last edited by PJmax; 05-23-14 at 08:27 PM. Reason: reoriented/resized picture
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  #2  
Old 05-23-14, 08:33 PM
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I redid your picture for you.

Just a few quick comments. I don't see any heavy loads other than the sub panel. What happened to the dryer and the range ? Are they no longer connected there ?
 
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Old 05-23-14, 11:31 PM
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Thanks for the reply!

The dryer is still connect in that spot. The range was converted from Electric to gas, so the double pole breaker was replaced with a single, effectively only charging one of the two hot wires.

I'm sort of wondering if it means that all of the breakers on the left side need to move up to the open slot, thereby creating two side by side slots.

Interesting enough, there was a 220V circuit run to a bedroom (not sure why) but that is the breaker pair on the right labeled SW Bed 220. Those are currently off as I don't really want an active 220V circuit in a nursery. That could effectively leave 4 slots open if I moved some things around.
 
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Old 05-24-14, 05:24 AM
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First of all , you will , by hook or crook , need two 1" ( total of 2" ) open spaces , side by side .

I would use cable with three # 6 copper current carrying conductors and one # 10 earth ground ( green or bare copper ) .

I would use a 2 pole 40 amp or 50 amp plug in circuit breaker . Is that a GE loadcenter ?

You want to install an outdoor loadcenter ? I would recommend something like

Shop Square D 24-Circuit 12-Space 125 Amp Main Breaker Load Center (Value Pack) at Lowes.com

except the circuit breakers that come with it are not what you are needing ? Still may be close to as cheap as you will find ? I think that is the one you were asking about ?

Be sure and keep the neutrals separate from earth grounds . Even if you have to buy a ground bar .

God bless
Wyr
 
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Old 05-24-14, 05:30 AM
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IIRC anything over 50 amp will require 2 1" spaces in your GE panel. To install a 100 amp breaker you will need 4 skinny spaces. This can be fairly easy since you can either move some things around, or get a THQL 40 amp and relocate that to where the range was.

1) Based on the attached image, will my primary panel even support an additional circuit this size?
Yes. See above.

2) Is 3/4 cable going to suffice with that wire length and amperage? 4) Where in the world should I get the wire? Clearly Lowes and Home Depot don't have wire like this, and what would be the best kind to use?
No. The length is not the issue, it is the size if you use NM-b. For 100 amps you would need 2/3 copper or 1/0 aluminum. According to my web search Lowes does carry 2/3 by the foot. If you can run conduit for the entire run you can use #3 THHN or #1 aluminum.

3) Can anyone provide a suggested outdoor sub panel that would be better to use?
That panel is fine, although you do not need a main breaker. Unless the breakers that come with it will be used, you could likely find a Main lug only panel for less money.

5) Obviously any outdoor sections will be clad in rigid metal conduit, but can I get away with supporting the wire by hanging it from the steel I beams in the crawl space?
PVC outside might be easier for you to run outdoors. I almost want to say you should also run PVC conduit under the house and use THHN wire. Can you post a picture of your crawlspace?
 
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Old 05-24-14, 06:57 AM
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You will probably run into bus stab limits attempting to add a 90 or 100 amp breaker. To do so so would need to loose any breakers installed across form the new breaker.
 
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Old 05-24-14, 07:46 AM
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No way I would use a 90 or 100 amp CB . That would require much larger wire than would be needed for the loads I remember him needing . Both the CB & the wire would unnecessarily drive up the cost of the project .

I do not know where he is , but around hear the AHJ requires schedule 80 PVC , if it is out of the concrete / dirt . On the outside . No kind of PVC is allowed out of the concrete / dirt , inside .

Do not ask me why ? PVC plumbing lines are allowed . I do not make the rules .

As far as the loadcenter , I would go to the supply house & buy a N3R Homeline MLO loadcenter , about 8 - 12 one inch spaces and what ever CB's were needed . And a ground bar is needed . I would buy one with copper buss , if the N3R loadcenter did not come that way , standard .

God bless
Wyr
 
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Old 05-24-14, 08:00 AM
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Sounds like the OP wants to power a future hot tub from the new panel along with other more immediate loads. A 60 amp feeder would not cut it IMO.
 
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Old 05-24-14, 08:59 AM
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Thank you all for your replies.

Couple things, PCBOSS is correct, I am looking to ensure that I can also run a hot tub circuit off of this panel. I only want to run something this large once, and ultimately, i'm running low on slots in the primary panel.

I've attached a couple pictures of the crawl space, even in the lowest spots, there is more than 2' of clearance from the steel I-Beams to the dirt.

So are we at #2/3 with a separate #10 or #8 ground? Would that ground simply be an extension of earth ground coming from the primary panel?

And yes, it is a GE panel. All of the labels are of course gone.

Thanks for locating the 2/3 wire at lowes, ouch on the price! 6.46/ft. that'll be $700 with tax down the tube (literally).
 
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Old 05-24-14, 09:42 AM
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You may be able to cut costs by running a feeder for the hot tub and a smaller feeder for the sub panel.

If I were you I would leave the large loads in the service panel and move smaller loads into a subpanel.
 
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Old 05-24-14, 09:51 AM
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Which wouldn't be too bad, I was hoping to run only one cable but if it cuts down on costs that would be good.

But in that case, I'd be looking at adding two large feeder breakers to the somewhat already full primary panel.

I've tried to research code on this but would that mean that I would need to run two separate pieces of conduit on the outside sections (one for each feeder wire) or can I run say a 1" conduit and run them both at the same time? Just trying to minimize the amount of exterior conduit.

If I do my math right, I'd be looking at running effectively two #6/3 wires, one for hot tub 50A and one for the say 50A 240 Subpanel? In that case I could actually use the ground that comes in the #6/3 sheath right?
 
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Old 05-24-14, 10:05 AM
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If you had enough spaces , yes , run 2 circuits . But looks like you are close to running out of spaces in the main / service loadcenter ?

I am not as familiar with a GE load center as I am a C-H / Bryant / Eaton or Sq D ?

Bryant made " quad " CB's , at one time ? Essentially one CB with two 2 pole CB's in one unit .

I think your hot tub would run off of 50 or 60 amps of 240 VAC ( been a long time since I wired one ) . The other portion of a " quad " could feed your new HVAC load center ?

Something like this is what I was trying to describe .

Shop Eaton Type BR 50-Amp Quad Circuit Breaker at Lowes.com

But I do not know enough about the GE load center to know if it would fit ? And would probably get yelled at if it would & if I suggested it . :-(

God bless
Wyr
 
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Old 05-24-14, 10:24 AM
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So effectively, that's a 100AMP pair in the space of two 1inch breakers... That could certainly be nice. I think i could move two single pole 15AMP breakers from the right side of hte panel to the left, and use the two spots from the bedroom 220 circuit, that would give me a total of four adjacent slots.

But now that I look into it, i don't think there is such a thing for a GE panel this old. Certainly can't find a quad... I think it's going to have to be two large 1inch breakers like this http://************/narj6uf and run a single circuit right?
 
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Old 05-24-14, 01:58 PM
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Looking at your crawlspace I think I would install PVC or EMT conduit and run THHN wire. There are many hangers that can be used to install pipe to steel beams like you have. It would be more labor, but I think it would cost less in material.

A Cuttler Hammer breaker should not be used in a GE panel. You have enough spaces in your main panel to add the sub panel, I see no reason to reinvent the wheel.
Thanks for locating the 2/3 wire at lowes, ouch on the price! 6.46/ft. that'll be $700 with tax down the tube (literally).
I think you might be looking at the wrong cable. 2/3 NM-b includes the ground wire. It is 2/3 w/ground. Also the price I see is $3.49 per foot. Unless your location is that much more expensive.
However, for comparison, If you ran 100' of 1 1/2" PVC conduit, and 3 x 100' of #3 THHN wire, it would cost about $189. Or $116 for #1 aluminum. Of course, you would need some other fittings, glue, and hangers, but this is just food for thought. You would also need a#8 ground wire if you use PVC.
 

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Old 05-25-14, 04:14 AM
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No way I would run aluminum . Besides , in our area , it is strictly limited . Do not know if it is , where the OP lives .

If that is not a GE loadcenter ? What is it ? ( Not saying you are wrong . )

It looks to have GE CB's ?

I have only messed with GE loadcenters on service calls .

By the way , there is a big difference between old C-H load centers and new C-H load centers . And the CB's are not the same .

God bless
Wyr
 
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Old 05-25-14, 08:47 AM
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Aluminum conductors are used safely every day and are a cost effective option compared to copper.

In my experience the new CH breakers will fit in the older panels.

Wyr, what the the restrictions on AL where you are?
 
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Old 05-25-14, 09:21 AM
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The OP's panel is a GE. which is why I said not to use Cutler Hammer breakers. GE breakers should be readily available.

Cutler Hammer has two panel lines, CH and BR. CH panels are the more expensive line, while BR is their "value" line. CH breakers will not fit in a BR panel. The BR line has the same breaker design as ITE/Siemens, Homeline, GE, Murry, Westinghouse, Bryant, Sylvania, General Switch, etc. While they are the same design each panel manufacture specs that only their breakers should be used in their panels.
 
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Old 05-25-14, 04:29 PM
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Again, thanks everyone or taking the time to make some suggestions. Really appreciate it.

Tolyn - do you have the Lowes item# you're looking at for 2/3 w/ ground cable? Want to double check on price, the item# I'm looking at is 113012.

Anyway, I know from past experience running multiple strands can actually be slightly easier trying to run one giant piece, but I could be wrong here. Technically I think THHN is allowed in Littleton, Co (slash Douglas County) so that could be okay. I'm okay with not saving the money on the AL wire, copper just makes me feel a little better, especially on a run this long, would hate to see the additional resistance cause unwanted voltage drop (even though the difference between the two metals is probably very small). PVC isn't horribly expensive so if you think it's the best thing to do, as in run the wire through PVC in the crawl space, I think I can swing that.

Wish I had a good electrician in my area that could even just look at thing like the primary panel and offer some quick advice (for a small fee), I don't mind doing the work it's just sometimes the "amateur" needs initial direction! I would even pay an electrician to do the final connections, it's just that in my experience they charge some astronomical prices. For example, recently I had to pay an electrician to convert the 240V circuit to my range into 120V circuit. After watching what he did, I definitely could have done the work, and he charged me $300 to do the work that took 20 minutes. I'm a consultant for billion dollar companies and i can't even charge that!
 
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Old 05-25-14, 09:21 PM
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Tolyn - do you have the Lowes item# you're looking at for 2/3 w/ ground cable? Want to double check on price, the item# I'm looking at is 113012.
Yup, that's the one. It appears to be on sale through 7/28/14. "Normal" price is $5.84.

While $300 does seam to be a bit high, based on your material costs you are quoting, it might not be that out of line for your area.
 
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Old 05-26-14, 07:14 AM
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We do not use Al wire , at all . Therefore , I will have to look up the wording ;

(w) Conductor material. Article 310.106(B) is hereby amended to read as follows:

(B) Conductor Material. Conductors in this article shall be of aluminum, copper-clad aluminum, or copper unless otherwise specified.

Exceptions:

(1) Conductors made of aluminum or of an AA-8000 Series aluminum alloy complying with Article 310.4 may be installed on services and feeders only. Aluminum conductors must be terminated properly using approved compression-type crimp lugs installed with a proper tool and with an approved oxide inhibitor. Such conductors may also be used as branch circuit wiring in commercial and industrial applications in No. 4 AWG or larger wire sizes, subject to the further conditions outlined herein.

(2) No aluminum conductors shall be installed on any branch circuits or grounding systems.


Over the years , I have seen a fair amount of stuff give problems due to Al wiring . Probably some or all were installed before the above restriction . Probably some or all would have been OK if " Hyplugs " had been crimped to the " tails " prior to termination .

The only time I ever used them , I just about ran out of room / space in the enclosure . :-(

God bless
Wyr
 
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Old 05-26-14, 07:31 AM
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Based on the amendment you posted, the OP's using aluminum wire for the installation would be acceptable in your location. (However the ground would need to be copper) He is installing a feeder, not a branch circuit.

I do agree that copper is better than aluminum, but aluminum can be just fine when properly installed.

Thanks Wyr! It is interesting to see rules from different states/locations.
 
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