Installing a new Sub Panel

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  #1  
Old 05-18-11, 05:55 PM
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Installing a new Sub Panel

Hi. I am looking for some advice on installing a sub panel to see if this is indeed something I can tackle. Here is the scenario:

I have an existing 100A service, with one spot left on the panel. I am installing a new hot tub, and need to run a 60A service to it. I am hoping to be able to install a sub panel that will provide what I need.

Questions:

Can I remove one existing 15A breaker to provide another space, and then install a 80A sub panel breaker to supply the sub panel?

Can I then install my 60A breaker for the hot tub, and the 15A breaker I removed from the main panel?

Thanks in advance to any and all advice.
 
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Old 05-18-11, 06:22 PM
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Short answer is yes, but I think I'd be doing some load calculations on the main panel first. You may not have sufficient capacity left in the 100 amp service to add the 60 amp service for a hot tub.
 
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Old 05-18-11, 06:59 PM
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Yes, that is part of my concern. How can I go about making this calculation? If it turns out that I don't have the capacity left to add the 60A service, what are my options?
 
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Old 05-18-11, 07:17 PM
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If the 100 amp service does not have enough capacity for the existing load and the new hot tub you are looking at a service upgrade.

Ray has posted a link in other posts for a demand load calculation. IIRC the website was bestinspectors or something close.
 
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Old 05-18-11, 07:38 PM
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Old 05-18-11, 08:11 PM
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Hi. I did a quick load calculation, and it looks like my current load is about 55A. So does that mean I am out of luck on adding a new 60A subpanel?
 
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Old 05-18-11, 09:02 PM
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What is the actual full load amps of the hot tub? Though not ideal I believe I have read some hot tubs can be set up so the pump and the heater don't run at the same time.
 
  #8  
Old 05-19-11, 04:31 AM
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It can be connected for 40, 50 or 60A. As you say, anything under 60A would mean the heater and pump(s) cannot operate together. The preference is to have it connected at 60A in order to have full & proper function, but if it means upgrading my whole panel from 100A then I guess I can live with lessened functionality. Based on a 100A service and a current load of 55A, can I get away with moving some things around and installing a 50A breaker for the tub?
 

Last edited by spungee; 05-19-11 at 06:01 AM.
  #9  
Old 05-19-11, 11:10 AM
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According to the tub specs, the current draw is:

40A Breaker - 26A
50A Breaker - 36A
60A Breaker - 45A
 
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Old 05-19-11, 11:40 AM
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I think you should wire it up for the maximum setting. If you have a problem with breaker tripping, then reconfigure the tub to a lower setting. I believe on Canadian code you need to wire the tub with either THHN in conduit or TECK cable. I am not an expert on CEC, so I would advise you check with someone who really knows it.
 
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Old 05-19-11, 04:21 PM
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Good point - I think that is what I will try.

I am running the THHN from my panel about 25 feet to the GFCI Load Centre - what size wire would you recommend? From the Load Centre, I am indeed running THHN through conduit to the tub, about another 15 feet or so. I am clear on the code requirements for running the service from the panel to the tub, just not 100% on some of the details!
 
  #12  
Old 05-19-11, 06:40 PM
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Originally Posted by spungee View Post
I am running the THHN from my panel about 25 feet to the GFCI Load Centre - what size wire would you recommend?
For 60A feeder THHN in conduit you need copper wires in sizes: 6 AWG (16 mm˛) for the two black hots and the white neutral and 10 AWG (6 mm˛) for the green ground. Some tub manufacturers require the ground be increased to 8 AWG (10 mm˛) so consult the manual. The conduit size should be no smaller than 3/4" (19 mm) trade size.
 
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Old 05-19-11, 07:11 PM
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thanks for the help! nice to get confirmation on these details
 
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