Electrical requirements for pool equipment + spa

[RecurveArcher]

I’m looking to run new electrical to the pool house to support 240V and prepare for a spa, hoping somebody can double-check my numbers and plans.

Currently we have two 12/2 wires going to the pool house from 120V 20A breakers in the main house panel; one powers the LP heater, the pump, and the SWG; the other powers the cover motor, outlets, and lights.

I’m planning to use a 240V 60A breaker in the main panel and run 6/3 UF-B wire out to a sub-panel in the pool house equipment room - about a 70’ run.

From there I plan to separate some of the equipment & outlets onto their own 120V 20A breakers, leaving myself some room to switch some to 240V. I’m then planning to pre-wire a 240V 50A GFCI breaker from that sub-panel to a control unit for the spa that will be mounted on the outside of the pool house wall across from the spa.

Without having selected a spa yet, it seems that 240V 50A should cover the majority, or at least what’s in our price range. Some stuff recommends running THHN wire, but from what I’ve found I can get a 100’ roll of UF for cheaper than 4 100’ rolls of THHN (to get 4 different colors). I’ll have extra 6/3 UF from the run to the first sub-panel, so I plan to use the leftover for the run through the walls to the 50A spa panel.

I wanted to try and verify the max load; the 60A sub-panel will support 14,400 watt max, with a safe operating capacity of 11,530. Here are the estimates that I came up with for our equipment:

Item - Max Watts
Pool Heater (Propane) - 400
Salt Water Generator - 250
Pool Pump - 1,200
Automatic Cover Motor - 1,300
Pool Cover Pump - 150
Automatic Pool Vacuum - 250
Misc. Lights (LED) - 100
Stereo Receiver - 250
Mini-Fridge - 150
Hot Tub - 7,500
Total - 11,550

It’s close to the capacity, but also highly unlikely that every single item would be pulling full power at the same time.

Does everything look good? Any thoughts or recommendations?

 

[uxbridgechris]

You are doing exactly what I would do. Not much I would change. The hot tub I had would pull 38 amps @ 240v with all pumps and heater running. Anything bigger would make me feel like you are cutting it close with 60a.

 

[kairus00]

Okay so a few things:

1) Code requires that pools have an insulated ground conductor, which UF does not have. Even though you could run UF to the sub-panel and then THWN from the panel to your pump/timer, an inspector would probably have a problem with it, saying that the panel is dedicated to the pool and there isn't an insulated ground back to the main panel. UF-B is a real pain to work with, especially #6, I wouldn't use it even if code allowed it.

2) You cannot use #6 UF-B with a 60 amp breaker. UF-B is derated to 60C, and #6 is only good for 55 amps. #6 THWN will be good for 65 amps.

3) You don't need to use 4 different color THWN. Get a green spool and a black spool. Your two hot wires can both be left black, or you can tape one up with red tape (or blue or whatever you fancy) on each end. Your neutral wire can be a black wire with white tape on both ends. This is very common and allowed. Your ground wire will need to be green, unless it's larger than #6 in which you would be allowed to mark a black wire with tape.

 

[kadavis]

What model heater is this, most gas heaters run on 24V so I don't understand the 400 W

 

[rickmail]

if it was me i would run 4 #2 copper or 1/0 aluminum feeder cable and put in a 100 amp sub. a hot tub pulls a lot of juice when its heating water after a change

 

[RecurveArcher]

Thanks for the input everybody, much appreciated!

Uxbridgechris: Thanks, that appears to be a bit more than I’d estimated for, so maybe I should bump up my spa usage.

kairus00:
1) Good to know on the insulated ground, I was not aware of that. I've worked with it before and was not really looking forward to doing so again.
2) I've seen some stuff that says 60A and other that says you can round it up since 55A breakers aren't available, but I think with the expectation that you aren't going to pull the full 60? I could be wrong, and I'll concede that I'm getting close to the limits so the 6/3 UF isn't ideal. From what I’ve found the #6 THHN is rated for 75A, is that wrong? Or is the 65A the “safe” max after accounting for some distance, temperature, etc?
3) I’m aware of using tape, I just prefer colors for my own OCD, but cost wise the bigger issue I’ve found is that spools don’t get cheaper until 500’ which is more than I need either way, so I’m looking at by the foot, which is (surprising to me) more than the UF; quite a bit so after adding conduit, etc..

Kadavis: I’m about to replace our heater with a Raypak 336K BTU LP. I assumed the heater wouldn’t take much electrical; it just needs to power the igniter and display, but I wasn’t finding much info so just threw out a number that I figured was more than enough.

Rickmail: If I work backwards, dedicate 50A for the spa, and everything else should be good with 20A, then 50+20 = 70A. If I’m went with the #6 THHN rated for 75A and adjust for temp it’s still over 71A, so it seems like running it off of a 70A breaker would work? It's still close, so I went ahead and priced out #4, ratted for 95A, with plans to use an 80A breaker in the main with a 100A panel (smaller panels don’t have enough slots). With that I could even do a 60A spa panel and should have plenty of capacity overall.
The #2 just seems like overkill for the needs, and that much harder to work with. I did price out the #2 and between the wire & conduit it was looking to be about $160 more, which is on top of a higher cost than I was expecting to pay to upgrade the wiring in the first place.
#4 is going to come in black, colors are available for #6, but #6 also comes in spools of 100' and would probably be about $60 cheaper overall vs. #4, but that cost isn't too much for the additional capacity of the #4.

Questions:
1) What is typically included with the spa purchase and/or installation? I can’t imagine it would cover running all new electrical from the main, but maybe hooking up the spa panel off of the 100A? Or would a spa panel would be included with the spa purchase? I’d like to get it all pre-wired while I have the walls off, but I don’t want to double-pay for that stuff either.
2) I was planning to get a GFCI breaker for the line from the sub-panel to the spa-panel, but the spa-panels indicate that they have GFCI built in; so do I just need a standard breaker on the 100A sub-panel? The spa panels are cheaper than just a GFCI breaker by itself so I want to make sure I’m not missing something there. I'm looking at the 'Eaton Type CH 60-Amp Spa Panels' (SKU 3676459 at Menards).

Summary:
The new plan is 80A breaker in the main, #4 THHN wire (with #6 ground), from the main, through 1” conduit, to a 100A sub-panel. Then #6 THHN from the sub-panel to a 60A spa-panel through 3/4” conduit.

Tentative Purchase List:
My full part list that I put together is below if anybody cares or it’s useful to anybody in the future; some of the wire is on sale at Menards currently, but it comes out to about $632 pre-tax. I might try to price out a few items elsewhere; the ground is from Amazon, Menards apparently only sells the green in large quantities and via special order.

Description Item Model Number SKU Store Price Quantity Total
80A Main Breaker Murray 80 Amp 2-Pole Circuit Breaker MP280 Menards $32.50 1 $32.50
100A Sub-Panel Murray 100 Amp 20 Space 40 Circuit Indoor Main Breaker Load Center LC2040B1100 Menards $75.90 1 $75.90
Main to Sub Load Wire Black 4 Gauge THHN/THWN-2 Wire (per Foot) SKU_3692405 3692405 Menards $0.79 250 $197.50
Sub to Spa Panel Wire 6 Gauge Black THHN/THWN-2 Feeder & Service Wire (per Foot) SKU_3692400 3692400 Menards $0.74 50 $37.00
Ground Wire 100FT 6 AWG 19 STR Stranded 90C 600V Green THHN/THWN-2 Cable B07BK48FMY Amazon $125.01 1 $125.01
1" Wire Conduit JM Manufacturing 1" x 10' Schedule 40 PVC Conduit 3652837 3652837 Menards $3.42 7 $23.94
1" Conduit Expansion Carlon® 1" PVC Expansion Coupling E945F-CAR 3652744 Menards $16.18 1 $16.18
1" Conduit 90 Elbow Carlon® 1" Schedule 40 Standard Radius 90-Degree Belled End Elbow UA9AFB-CTN 3653004 Menards $1.18 7 $8.26
1" Conduit 45 Elbow Carlon® 1" Schedule 40 Standard Radius 45-Degree Belled End Elbow UA7AFB-CTN 3653017 Menards $1.17 2 $2.34
1" Conduit Coupling Carlon® 1" PVC Electrical Coupling E940FR-CTN 3652743 Menards $0.45 8 $3.60
1" Conduit Adapter Carlon® 1" PVC Box Adapter E996FR-CTN 3652225 Menards $0.68 2 $1.36
1" Conduit Clamps Carlon® 1" PVC Conduit Clamps - 5 pk E977FC-CTN 3652866 Menards $1.29 1 $1.29
1" Conduit End Bell Carlon® 1" End Bell E997F-CAR 3652034 Menards $0.99 1 $0.99
3/4" Wire Conduit JM Manufacturing 3/4" x 10' Schedule 40 PVC Conduit 3652086 3652086 Menards $2.50 2 $5.00
3/4" Conduit Elbow Carlon® 3/4" Schedule 40 Standard Radius 90-Degree Belled End Elbow UA9AEB-CTN 3653003 Menards $0.85 4 $3.40
3/4" Conduit Adapter Carlon® 3/4" PVC Box Adapter E996ER-CTN 3652224 Menards $0.56 2 $1.12
3/4" Conduit Coupling Carlon® 3/4" Schedule 40 Coupling E940E-CTN 3652358 Menards $0.29 4 $1.16
60A Breaker Murray 60 Amp 2-Pole Circuit Breaker MP260 Menards $9.40 1 $9.40
60A Spa Panel Eaton Type CH 60-Amp Spa Panels CH60SPA 3676459 Menards $85.99 1 $85.99

 

[kairus00]

Ground Wire 100FT 6 AWG 19 STR Stranded 90C 600V Green THHN/THWN-2 Cable B07BK48FMY Amazon $125.01 1 $125.01

$125 for 100 feet of 6 AWG green THHN is too much. Home Depot has it for $60. The product listing says THHN, but it is rated THHN/THWN for 10-14AWG, and rated THHN/THWN-2 for 8AWG or larger. Their product brochure confirms this, and you can verify the markings on the wire in person.

From what I’ve found the #6 THHN is rated for 75A, is that wrong?

It's not wrong, but you can't use the 90C rating unless everything is rated at 90C. So the connections on your devices, panel, disconnects, etc. You'll find that most terminals are 75C rated.

2) I was planning to get a GFCI breaker for the line from the sub-panel to the spa-panel, but the spa-panels indicate that they have GFCI built in; so do I just need a standard breaker on the 100A sub-panel? The spa panels are cheaper than just a GFCI breaker by itself so I want to make sure I’m not missing something there. I'm looking at the 'Eaton Type CH 60-Amp Spa Panels' (SKU 3676459 at Menards).

I looked up the specs on the spa panel, and it includes a 2-pole 60a GFCI breaker and it is much cheaper than separately buying that same breaker it includes. Funny! I would buy the spa panel.

Seems like you are familiar with electrical work, but remember neutral and ground should only be bonded in one place (service entrance), and not in a sub-panel.

 

[RecurveArcher]

Hey, thanks again. I actually just came back to this about 30 minutes ago to do some price shopping and found the exact same green wire at Home Depot; that's the only place I've found it at a reasonable price, funny the green is so much harder to find.

The only other item I found cheaper is the 100A panel, which is on Amazon (AISN B007Q1BP6O) in the value pack version for $58 ($18 cheaper + includes 6 breakers).

I added on some colored electrical tape to my list; with that and the two changes above the cost is currently at $556.08 (plus a "fun" day of work).

 

[jimmythegreek]

I buy my thhn on Ebay there are sellers that have precut lengths for great prices. Your new plan is good you can install whatever size breaker into the main spot you only need a small 8 space sub panel. Remember if you share a conduit with a gfci circuit all additional circuits in that conduit must also be gfci

 

[ajw22]

My understanding is rated loads on a CB need to be a max of 80% of the CB capacity.

 

[RecurveArcher]

Finally finished re-wiring the rest of the equipment into the pool house panel, and the spa panel is wired and installed on the outside wall, ready to go.

The panel was one of the package deals with 6 breakers, so I went ahead and put most stuff on its own, so one for the heater, the pump, cover motor, SWG, pool lights/GFCI outlets, and then interior lights and outlets. Plus threw in an extra double-pole that I had sitting around, figure I might need that if/when we replace the current pump.