Hot Tub - Electrical Plan - Thoughts ?


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Old 06-04-14, 04:01 PM
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Hot Tub - Electrical Plan - Thoughts ?

Hi All

Firstly - sorry for the long post.

Im going to be installing a hot tub shortly and would like to run the electrical plan past the experts here. The preferred location for the hot tub is outside at the other end of the house from the electrical panel. Probably at least a 130ft run from the panel.

The panel has a spare 50amp 240V breaker (due to an old range that was replaced with a Gas Range). The panel is located in the garage. The hot tub will be on a concrete pad (6in thick with rebar) approximately 10ft from the house outdoors.

I had thought of re-using the wire that runs from the panel to the kitchen to supply the hot tube but its only 6-2 plus a ground. I need a neutral according to the spa manufacturers guidelines so Im going to have to run a new wire the entire way.

The plan is to do the following:
Run around 130ft of NM-B 6/3 from the panel as follows:
          So my concerns / questions are:
                        I'm in NJ, USA.

                        Thanks
                         
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                        Old 06-04-14, 04:33 PM
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                        Welcome to the forums.

                        I was going to bond the rebar to the spa bonding bus as well is this necessary ?
                        Yes.... use #8 bare or green.

                        You should be connecting the spa panel to the spa with PVC. EMT is not rated for underground use. Three #6's and one #8 in a one inch PVC conduit. Where the PVC exits the ground under the tub you can change to sealtite (flex) conduit to go to control panel.

                        You can run the NM directly into the back of the spa disconnect.

                        Receptacles between 10'-20' away should be good. Spa disconnect at 5' is ok.
                         
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                        Old 06-04-14, 04:45 PM
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                        thanks for the welcome - long time lurker!

                        The spa needs 4 x hot plus neutral and a ground. so 6 wires in total. 1 20amp 240V and one 30amp 240V circuit on separate GFCI's.

                        So i think I'll go to 1 1/4 inch PVC at least...
                         
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                        Old 06-04-14, 04:53 PM
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                        1 20amp 240V
                        Did you mean: one 20 amp 120 v?
                         
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                        Old 06-04-14, 05:03 PM
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                        That's a pretty strange power requirement. All the ones I've done run on one circuit.... usually 240vac....30A/40A/50A...... some with neutral and some without.
                         
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                        Old 06-04-14, 05:28 PM
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                        Yes - I thought it was as well.

                        Its 50A to the spa disconnect and then from there it splits into two 240V circuits.

                        The theory I guess is that you put the heater on one circuit and the pumps on the other. Therefore if the heater blows the breaker - most likely - then as long as the 50amp at the panel doesnt go - you still have the circulation pump running.

                        Here is the wiring diagram.

                        Name:  Wiring.jpg
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                        Will find out for sure when the hot tub actually gets here and I can take a look at the internals.
                         

                        Last edited by mick999; 06-04-14 at 05:39 PM. Reason: typos....
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                        Old 06-05-14, 02:30 PM
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                        A junction box on the inside of the wall would switch to THHN in EMT thru the wall to the spa disconnect.
                        I would not use a J-box and run the 6/3 right into the sub panel.

                        From the Spa Disconnect run EMT down to 18 inches underground, 10ft across and up thru the pad into the spa housing.
                        Wire would be 6 cores #6/#8 AWG THHN in a 1 inch EMT.
                        You may not bury EMT. Only PVC or rigid conduit is alowed in the ground. I suggest PVC.
                        The wire from the subpanel to the pump/heaters only need to be sized to the breakers protecting them. So, as the diagram shows, you only need 3 #10 and 2 #12. A 3/4" or 1" pipe would be plenty big.

                        Is 6/3 large enough for this type of run or should I go to 4/3 ?
                        6/3 NM-b is fine for your cable and in a basement.

                        Ive read that a separate GFCI 120V outlet is required within X ft of the hot tub as well. On my deck (around 6ft off the ground) I have external GFCI outlets which would be within 20ft (as the crow flies)
                        IMO this sounds OK, however you should check with your AHJ.

                        Is there a minimum height for the spa disconnect above the ground ?
                        There is no minimum, but there is a maximum. The highest breaker can't be higher than 2 meters, or 6'7" off the ground. 5' would be fine. Be sure the spa panel is rated for outdoor.
                         

                        Last edited by pcboss; 06-05-14 at 07:18 PM. Reason: 6' 7" was 6' 6"
                          #8  
                        Old 06-14-14, 06:04 AM
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                        hi another question

                        I have found a sub panel in the basement that appears to not be to code. I am concerned that it might give me some issues and have decided to replace it with a 100amp subpanel and then run the spa run from there. The existing panel is a 120V panel with a 20amp feed of romex in conduit. not good.

                        I traced the cable back to the main panel and its been run thru the garage wall studs around 1ft above ground level covered by drywall. My thought is to replace this with 1/0 ser from the main panel to the new sub panel. The studs are 2 x 4 probably load bearing. Is it ok to use the existing holes to run the 1/0 ser cable thru? im concerned about what size the hole needs to be. The cable is a little over 1inch in diameter. Also there is one 90 degree bend at the corner of the garage thru the corner stud which the ser cable would need to run thru.

                        Or is it a better option to run the ser thru conduit along the garage wall to location I can enter the basement? Can it run at about 2 inches off the ground in PVC 80 attached externally to the drywall and studs?

                        It would be about a 60ft run of 1/0 1/0 1/0 2 SER Al cable.

                        Thanks
                         
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                        Old 06-14-14, 06:24 AM
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                        You are not going to be able to make that bend going through the studs.

                        If you run that low to the floor I would consider that subject to damage and you would then need Schedule 80 conduit.
                         
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                        Old 06-14-14, 07:11 AM
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                        Hi Thank you for your comments

                        Is Ser allowed in conduit? Seem to be reading mixed opinions on this
                         
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                        Old 06-14-14, 08:17 AM
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                        It can be sleeved for protection. Individual conductors are easier to install in conduit than a cable.
                         
                         

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