Background (skip if you want):
I’m putting this here instead of in the Pool control because well…this isn’t really a big pool…LOL. So we, on the spur of the moment, bought a small 10’ x 30" round “easy set” pool for the kids for this summer. We don’t really have room for a normal pool in the yard between the playset, geodome (monkey bar kinda thing), and the placement of the septic and drain field. Not to mention my newly built (last year) 12x24’ shed. So we just got this pool and threw it on the patio and I fenced it off with some plastic chicken wire and rebar to keep the dogs away and the kids out unless we are near there (I will put a proper temporary fence up over the next week or so, but the chicken wire shoudl do for now).
The issue:
The pool came with a small pump with a built in GFCI circuit. I have some outlets around the house and patio, so I quickly swapped out one for one of my spare Enerwave outlets (the first outlet in the chain is a GFCI, so this outlet should be protected). My issue I’ve run into is that for some reason, when the GFCI plug on the pool pump loses power, it trips! So I can’t control it via the Vera. AT best I can just turn it off. I don’t really want to run the thing 24/7. I’ve done my research and I’ve found that about 6-8 hours a day should do fine (after starting it off for 72 hours straight).
I’m curious if anyone has an idea how to get past this. I’m not willing to mess with the plug, but I was thinking maybe it was the outlet. I’m considering getting a Aeon microswitch and throwing that in there instead of the enerwave because then I could at least see how much power it was using and then create a PLEG that says “when it’s using more than 0w, turn it off after 8 hours”. This would mean I have to manually start it every day, but at least I wouldn’t have to turn it off. The other benefit is that there is a “switch” in the same box for controlling the outlet, so I could hook that up to the microswitch and have control over the outlet/microswitch from there.
BTW, the motor only uses about 46watts (according to the manual), so I’m sure it’s ok to use on the outlets/switches. Of course if i’m wrong, then I’ll remove it from z-wave all together and just do it all manually.
It sounds as though the pump’s plug has a built-in no-volt release. These are more common on power tools but maybe the manufacturer thinks it is a valuable safety feature.
If I was wanting to automate it I would just cut the plug off and rely on a GFI socket. Warranty? It’s only money.
[quote=“Bulldoglowell, post:2, topic:180909”]I haven’t seen a GFCI trip with a power loss. It might be there as a safety feature to keep the pump from energizing unattended.
I would also check the GFCI that’s on that circuit, it could be messed up.
what about an old fashioned mechanical timer?[/quote]
I don’t think it’s the GFCI circuit as my landscape lighting (what little I currently have) is on that circuit as well as a fountain. All after the switch in question.
They actually have in the manual to not use a timer. I’m guessing this is why? I find it odd that they don’t mention it in the documentation though if this is a “safety feature”.
[quote=“RexBeckett, post:3, topic:180909”]It sounds as though the pump’s plug has a built-in no-volt release. These are more common on power tools but maybe the manufacturer thinks it is a valuable safety feature.
If I was wanting to automate it I would just cut the plug off and rely on a GFI socket. Warranty? It’s only money. :D[/quote]
That’s not a horrible Idea. I can just put the original GFCI switch in there and put a microswitch behind it. After all, I know the original GFCI doesn’t trip when it loses power because the box came with a switch in it to control the GFCI switch. I’ve attached an image of my box. I really think this might work…
And you’re right, it’s not like for the cost of the pool ($60) I would try and get the pump replaced if it fails. Chances are the kids will find a way to tear it open before that even happens! LOL
Perhaps. Originally I wasn’t willing to cut the power plug off, but I think I’ll be good if I put the original GFCI outlet in there and use a microswitch to control it. I think that will ultimately still keep me pretty safe (not to mention there are other GFCI outlets up stream from it).
Cascading GFCIs is not a good practice. A ground fault will create a race condition and only one of the GFCIs will fire (trip).
Sounds like the GFCI with the pool has a fail safe mechanism to trip on power loss to force user to make a deliberate reset upon repowering. You can’t change or cut out thus device due to the safety listing is provided on the basis of how it was certified by manufacture. Simply put if you cut off the pool GFCI you void any UL listing.
[quote=“curiousB, post:8, topic:180909”]Cascading GFCIs us not a good practice. A ground fault will create a race condition and only one of the GFCIs will fire.
Sounds like the GFCI with the pool has a fail safe mechanism to trip on power loss to force user to make a deliberate reset upon repowering. You can’t change or cut out thus device due to the safety listing is provided on the basis of how it was certified by manufacture. Simply put if you cut off the pool GFCI you void any UL listing.
Sent from my iPad using Tapatalk[/quote]
I did not know that about cascading GFCIs. I always figured the one closest to the fault would trip since it should keep it from going up stream (I thought that was the point). However it does now explain some issues I’ve had with some of my GFCIs forcing the last one in the chain to trip instead of itself. I will do more research on this and figure out what to do.
Would it be better to replace all the following GFCI circuits with regular outlets, or wire them so they go line → line → line (as opposed to line → load → line). Honestly, the only reason I have GFCI outlets on them all is because the boxes came with them (there is no option to buy that box without them) and I happen to like that box (it’s big, can have wall warts plugged into them, and they lock with a standard lock).
Did a little more reading on this. The cord gfci might be tripping due to back emf of the slowing down pump motor. The line side is switched off but the motor sends a voltage back to GFCI (called back EMF). Most GFCIs are designed such that if you wire line feed to the load side of the GFCI (i.e. wired in backwards) they instantly trip as a safety mechanism. Back to your scenario, the line side is now open circuit because your ZWave switch turned off yet it sees voltage on the load side (back EMF of rotating motor). The GFCI thinks its wired backwards since there is no voltage on line side, yet voltage on load side. The GFCI then trips. To test this theory try plugging hot tub into a non gfci outlet and fire it up. With the pump motor running, yank the cord from the outlet and see if the hot tub cord gfci trips.
If back EMF is tripping your GFCI then controlling hot tub via line side switching is a nogo. You’ll need to switch unit off another way. Also keep in mind hot tubs and swimming pools have very strict grounding, gfci, and isolation rules under the NEC and UL. You need to understand unintended consequences of interfacing to control such a device with HA. Even interfacing with dry contacts to the low voltage control side of the spa has some concerns. The spa maker has certified all the protection and isolation from the line voltage to the low voltage side of the circuits. Adding anything to the LV side might functionally work fine but fail to meet the isolation and barrier requirements from line side to LV side. So as I said proceed with caution.
I believe Intermatic makes some heavy duty two pole zwave contactors (CA3750) you could wire into the control panel where the line voltage comes into the spa. Since that is after the Cord GFCI, switching here won’t cause the back emf issue to the GFCI. Again this might void warranty and UL listing however so wade in eyes wide open…
GFCIs are actually fairly simple. They compare current in the neutral line to that of the hot line. If they are equal it assumes everything is ok. If they are not equal it assumes a ground fault and then trips.
Now consider multiple GFCIs in series. A ground fault occurs and each GFCI then sees an imbalance in the hot and neutral lines. So each one then decides to trip. The catch is, the one that trips first wins. The others won’t trip because in the first one tripping the ground fault is removed. This is the race condition I spoke of. It can vary by brand and unit to unit as to which one “wins”. This is why it is bad practice to cascade GFCIs. You press the test button on the last gfci in the stream but the gfci first in line trips. You wonder why power is lost but the gfci where you pressed the test button didn’t reset. Very confusing.
All exterior outlets must be GFCI protected per the NEC. If you remove the GFCI in the exterior box then that outlet is not protected and someone could plug in anything and it would in turn not be GFCI protected. You cannot assume only a hot tub with a downstream GFCI will only be plugged into this outlet. So the answer is no you can’t use a regular outlet there.
All exterior outlets must be GFCI protected per the NEC. If you remove the GFCI in the exterior box then that outlet is not protected and someone could plug in anything and it would in turn not be GFCI protected. You cannot assume only a hot tub with a downstream GFCI will only be plugged into this outlet. So the answer is no you can’t use a regular outlet there.[/quote]
This is fine and done all the time. The first outlet outside fed from the panel has a GFCI then the rest of the outlets are just weatherproof duplex outlets wired to load side of the first GFCI. You then put a small sticker on each downstream outlet to say it is GFCI protected. The stickers come with the GFCIs.
You can also put GFCI outlets at every outdoor location but just wire them all on the line side of the GFCI and don’t use the load side terminals on any of them. GFCIs are pretty cheap now so you avoid the confusion of one getting tripped but you aren’t sure where it is. Where it gets crazy is when there is a GFCI inside say in a bathroom or garage and the builder cheaped out and ran the outside plugs off the load side of that GFCI. Then you get a ground fault trip outside and who thinks to check inside?!!
This still doesn’t solve your issue of the cord based GFCI on the spa. You should try the test I mentioned and report back. Need to know if the back EMF theory is the fault condition or something else.
This is fine and done all the time. The first outlet outside fed from the panel has a GFCI then the rest of the outlets are just weatherproof duplex outlets wired to load side of the first GFCI. You then put a small sticker on each downstream outlet to say it is GFCI protected. The stickers come with the GFCIs.
You can also put GFCI outlets at every outdoor location but just wire them all on the line side of the GFCI and don’t use the load side terminals on any of them. GFCIs are pretty cheap now so you avoid the confusion of one getting tripped but you aren’t sure where it is. Where it gets crazy is when there is a GFCI inside say in a bathroom or garage and the builder cheaped out and ran the outside plugs off the load side of that GFCI. Then you get a ground fault trip outside and who thinks to check inside?!!
This still doesn’t solve your issue of the cord based GFCI on the spa. You should try the test I mentioned and report back. Need to know if the back EMF theory is the fault condition or something else.[/quote]
Yeah, I have to be careful because I have a mix of z-wave outlets and GFCI so I think it will be best to just replace all the GFCI outlets with normal ones. Had I thought about it, I would have run 12/3 instead and been able to run a line for the GFCI’s and one that just came off the first GFCI outlet. I didn’t know this was an issue then, so it’s not like I feel that bad about it.
As for the kids pool, I think I’m just gonna give up on automating it. I’m gonna swap the outlet back out for a GFCI or a normal one and be done with it. I think I figured it woudl cost me $3.30/month to run it. It’s just an “easy set” vinyl pool (10’ diameter and 30" deep). It’s not huge and it will be drained and put away in the fall. That or until the kids pop it…LOL
Thanks for all the information. I didn’t really solve the pool issue, but you gave me the solution to a problem I’ve been having that I had no idea what it was doing it (the GFCIs tripping further down the line than the one that had the fault).
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