Need electrical help/suggestions on small soaking pool

[tribly]

Hi all! Mid way through a little DIY soaking pool / hot tub (full thread if you're interested: DIY Concrete Block Soaking Pool - In Progress, Advice Welcome!!). And getting to the point where I need to finalize some electrical stuff. Don't know much about it, but want to make sure I understand how it all works and don't get anything wrong (or get anyone electrocuted!).

Here's the equipment I'll be hooking up (photos of heater/pump plate below):

1. 240volt, 5.5kw heater (pulls approx 40 amps)
2. 120volt, 1hp pump (pulls approx 10 amps)
3. Small, 120volt pump for fountain (in future)

Here's the plan right now
- Install a 70 amp breaker in my main electrical panel
- Run wire (#4) from main panel, outside, through buried PVC conduit (probably 3/4 or 1"), to a sub-panel near the pool (total distance is about 60 feet)
- Sub-panel will be 4 space (8 circuit) (box is 125 amp max, but I'll only be installing 70 amp total in breakers)
- I'll install a 30amp, 240volt, 2-pole GFCI circuit in the sub-panel and wire the 5.5kw heater into that (4 wires, neutral, 2 hot, ground)
- I'll install a 20amp, 120volt, 1-pole GFCI circuit into the sub-panel and run that to an outlet where I'll plug in the 1hp filter/pump, and also run it to a 2nd outlet where I'll plug in the small, fountain pump
- Leave space for another 120volt, 20amp GFCI circuit in future if I need
- Bonding wire (already tied into all the concrete) will be tied into the heater and filter/pump

Just a few questions (sorry if they're dumb/obvious):

1. Does the breaker I'll install in the main panel to connect to the subpanel have to be GFCI protected? Does it have to be 70amp (since the total I will potentially install in the subpanel is 70amp)? Right now I've only ever seen 60amp max GFCI breakers for sale so not sure how that'd work?
2. Shows my limited knowledge, but I see that the 2-pole circuits are listed as 120/240volt. So what exactly determines if a device (outlet, hard wired heater, etc) will use the 120 volts or 240 volts?
3. Any other insights or comments or things you notice that look wrong?

Again, my electrical knowledge is limited and so I'm happy for any advice or feedback. Thanks!

Heater

Pump/filter

 

[gwegan]

As I said before you are on the cusp. I think you could get by with a 50 amp double pol breaker at your panel. But put a 70 in to be safe. The breaker size should be no more than 75% of your expected load. Don't double up on GFCIs. I would not put one in the main panel just in the sub panel. That way when they trip you (or the next guy) can't determine what is wrong. Your neutral and ground are isolated all the way back to the main panel.

240 total on two 120 volt lines. You must make sure you wire the heater correctly for 240. Where you have 2 hot wires and a ground. Usually no neutral. How you wire is is what determines the voltage it operates on.

I would run each of the pumps off a separate circuit. I would have a separate circuit for my utility plug. Use GFCI outlets for all of these (20 amp outdoor weather resistant) cost less than breakers.

No more than 6 circuit breakers in the subpanel no matter what the rating of the panel.

What are you sizing the wire for the main panel to subpanel run?

 

[tribly]

Thanks again, gwegan. Just wanted to double check things before I start buying.

What are you sizing the wire for the main panel to subpanel run?

Was gonna do #4

 

[tribly]

Researched a bit more on wires. Guess it'll probably be:

2- #4 THHN wires Black for main loads
1- #6 THHN White for neutral
1- #8 THHN Green for ground


Sent from my iPhone using Tapatalk

 

[tribly]

What are you sizing the wire for the main panel to subpanel run?

Actually, since not grounding the subpanel, only need:

2 - #4 THHN Black for hot
1 - #6 THHN White for neutral

 

[gwegan]

The subpanel MUST be grounded. The ground bus bar must be bonded to the subpanel enclosure (attached). The neutral bus bar in the subpanel must be floating - insulated from the subpanel enclosure and isolated from the ground bus bar. Both the ground and neutral run from their respective bus bars in the subpanel to the common neutral ground bus bar in the main panel. So you need a ground wire running from the subpanel to the main panel.

Make your hot conductors different colors -- red and black.

This website has some good illustrations: How to install a subpanel / How to install main lug

Your subpanel is basically the first example.

This diagram is also good: Splitting 220 wire for new sub panel.

 

[tribly]

Excellent! Thanks again, gwegan! Super helpful. Think I got it all sorted out now (and that waterheatertimer.org site is super helpful).

I'll let you guys know if I have any other questions. Thanks again for all the help!

 

[Frank Rizzo]

It looks like your pool heater draws 16A if wired in 240v (according to your picture). That means you could run #12's if you are wiring it 240v. It also means that #4 could be overkill and you could save a few bucks by running #6 and dropping down to a 50A main breaker - assuming you don't need to add any other big loads later.

Im a belt and suspenders guy, so I'd sink another ground rod at the equipment if you can. a 5/8" 8 foot long rod. Rent a spline drive hammer drill from Home Depot and use it in hammer mode to drive the rod into the ground.