Trying Not to Electrocute Myself :) - Tapping a subpanel for a Maytronics m400

[slickrock22]

I just purchased a new Maytronics m400. Amazing! Instead of dragging an extension cord down the back stairs and along the pool just waiting for one of my children to kill everyone in the pool, I thought of a better approach. Even though my pool equipment is about 75 feet away, downhill and on the east side of the home, right near the pool on the west side of the home, there is a sub panel (hooray) for the pool equipment. It is a 220v subpanel and the wires for the pool equipment are just wired directly to the incoming wires from the main panel. I purchased the correct 20amp breaker (110v) Also, as you can see in the picture the ground are bonded to the neutral bar. In some reading it said that this is fine at the main panel, but a big no-no at a subpanel. There should be an installed Square D PK7GTA ground bar on either the bottom left or right of the box. That is easy enough to remedy. Since this seems to really only be acting as a junction box and not a true subpanel I just wanted to make sure that I was not under thinking anything.

Also if I add a grounding bar, do I need to add anything like a rod in the ground near the subpanel and connect to the grounding bar?

Any help is greatly appreciated (and yes I always turn the power off to the subpanel and verify with volt meter - 220v scares the heck out of me)

The subpanel is a Square D QO Load Center QO6-12L100RB.

 

[BestJoeyEver]

So yeah, that box is currently a junction box, which is odd. But if you want to make it a sub panel you can, but it can be both. If you add a breaker for your outlet, you should add a breaker for your pool equipment. (I'm going to assume that you've already verified the breaker inside and the line to the sub pannel is sufficient for the additional load).
You should also make sure that the breaker feeding this box isn't a GFCI breaker as that may cause issues (depending on the code in your area).

Disclaimer: Since I'm not a qualified electrician in the jurisdiction where you live, you should additionally seek the advice of a competent professional. Any advice you get on the internet, you should carefully review.

 

[slickrock22]

Thanks very much. If I kill myself that is on me. I was wondering if I should add a breaker for the pool equipment as well. Great point on calculating the amp load. The main is not a GFCI but will double check. Thankfully I am no longer using my 220v booster pump and I only envision using this outlet for some light welding in the backyard when the pool equipment is off and the m400. If I exceed the total amps of the breaker in main box 50 AMP by having a 20 AMP + 50 AMP in the sub panel, wont it just throw the main breaker. I don't think this will ever happen but better safe than sorry I guess. What is really interesting is that the wire coming from the main panel to the sub is super thick but the wire seemingly going to the pool equipment is much lighter gauge. Surprised you can make a 220v run 100ft with that low gauge of wire. I am not an expert tho.

So yeah, that box is currently a junction box, which is odd. But if you want to make it a sub panel you can, but it can be both. If you add a breaker for your outlet, you should add a breaker for your pool equipment. (I'm going to assume that you've already verified the breaker inside and the line to the sub pannel is sufficient for the additional load).
You should also make sure that the breaker feeding this box isn't a GFCI breaker as that may cause issues (depending on the code in your area).

Disclaimer: Since I'm not a qualified electrician in the jurisdiction where you live, you should additionally seek the advice of a competent professional. Any advice you get on the internet, you should carefully review.

 

[slickrock22]

Trying Not to Electrocute Myself ? - Tapping a subpanel for a Maytronics m400

Job completed. Change the box from being a junction box to a true sub panel. Added a new independent ground bar. Added a 220v 50amp breaker as well as a 20 amp 110 breaker. Used outdoor conduit and surface mount box with weather protective cover.

My dolphin is as happy as ever.

 

[danpik]

In your first picture, the neutral and ground on the same strip is a big No-No. With that setup, there is neutral/return voltage on the ground wire as well. The grounds need to be separate and the neutral needs to be a "floating" or isolated bar. It looks like there is a bond screw in place near the neutral wire connection that would have to be removed to float the neutral.

The second issue, that you seemed to have resolved with the addition of a breaker(s) is that you can not have two conductors under the same screw on both the feed and neutral connections unless the manufacturer has specifically rated the terminals for multi conductors. I have not seen any like this for years now.

Amp load is not calculated by adding up the breaker ratings. You need to find the nameplate on each device and use the FLA (full Load Amps)rating to determine the amp load. You can have more total breaker amps available in the box than the main is rated for. However, if you have a breaker(1) that is rated higher than the main, you most likely will have a problem.

It looks like (original picture) there is two neutral wires coming into that box via the back of the box?

Separate ground rod is only required if the sub panel is on a separate building from the main panel.

What gauge wire is feeding the panel and what breaker is in the main supplying it?

Dan