Grounding question

[toecheese]

My house has some screwed up pool wiring. My pool pump has a 220V line running to it--two hot wires and a white. The white wire is hooked up to the pump's ground in the connection box. However, the white is also split off and connected, along with one leg of power, to a 110V spa pump.

The wire conduit running to the system is plastic, so it's not grounded. It looks to me like there is no proper electrical ground in the way the previous owners wired the pool.

However, the pump does have the heavy duty ground wire running from the bonding lug on the pump to a pipe deep inside a wall. Is this sufficiently safe grounding for the system if there is no ground wire coming out of the conduit?

 

[jblizzle]

That does not sound correctly wired at all. You should not split a 230v circuit like that. Really each pump needs to be on its own breaker with its own wiring.

The exterior wire is for bonding. Which is a completely different purpose from the ground wire (which should be green, not white).

The white neutral wire for the 120v circuit should also be isolated from all the ground wires if you have a subpanel.

 

[gwegan]

When was the pool built?

Pictures would be helpful.

Pools have two different electrical safety systems that work together to protect people and equipment. Generally all electrical systems in a pool must be connected to a ground wire that terminates in a ground bar in a panel or service entrance. If associated with a pool it must be insulated, not bare wire (usually green insulation). The conduit cannot serve as the ground in a pool application. Pool grounding provides a low resistance alternative path for current to complete a circuit.

A pool must also have a bonding system which connects non conductive elements of a pool which may become energized so that they all have the same electrical potential. Pool bonding differs from grounding in that it attempts in the event of a "current leak" or stray current to make all elements of the pool equally "charged" or having equivalent electrical potential so that any person coming into contact with the pool would be charged but would not become a conductor.

You can post some pictures and we can look at them and tell you what we see. What you describe may be ok or not ok. Or it may have been ok when installed. Without some pictures I really can't begin to give you an intelligent answer.

But because I suspect your pool is old I would suggest having a competent pool electrician out to give the pool the once over and tell you what improvements can be done to bring your pool up a couple of notches on the safety latter.

 

[toecheese]

Thanks all. Here's an update: first off, I was looking at the label on my spa blower and discovered it is actually a 220V pump, but it's been incorrectly wired to 110! It's been like that, and running fine, for over 15 years. Rewiring it to 220 will at least put all the equipment on the proper 2-wire 240V wiring, and I will then cap off the white neutral and leave it unused. I also had an electrician come out to look at the grounding. He told me I could just do my own ground (and save his $350 fee) by driving a grounding stake into the nearby earth and then wiring the equipment and switch boxes to it (alternately I could string a ground wire through the conduit, but really the conduit is just too long and becomes buried in dirt and concrete). That plus the heavy duty bonding lug ground wire will be sufficient. He also told me I didn't need to bother with a GFCI breaker, since my pump equipment is nowhere near my pool. That one I'm not so sure about, since my pool guy regularly has to splash water around when he cleans the filter.

 

[jblizzle]

Remember grounding and bonding are completely different things with different wires and different purposes.

In your post I could not follow which one you were actually talking about.

 

[danpik]

Ground rods will not clear a fault. This is electrical 101. for the layperson, this means that in the event of a short circuit, the circuit breaker will not trip if the ground wire is connected to a ground rod. Ground rods are for high voltage events such as lightning strikes. In order to clear a fault (trip a breaker) a ground wire needs to return to the service grounded conductor which is better known as the neutral. This connection has to happen at the first entrance point (service disconnect) at the service.
to properly repair your pool, you need to get an insulated green grounding wire out to the pumps from the service panel. It may be possible to re-purpose the white wire. it will need to be recolored green on both ends. This can be done with paint or green heat shrink tubing. The ground wire does not connect to the large lug on the pump. There should be a grounding screw inside the connection area on the motor.

Here is a great Mike Holt video on grounding and ground rods. Grounding - Ground Resistance Measurement, 250.53(A)(2) (26min:27sec) - YouTube

 

[toecheese]

Thanks--yes, I understand that the electrical circuit's grounding wire is not for the bonding lug on the pump. This electrician told me that if I installed a ground rod and wired it to the electrical box connections of the pump and the other devices, that that would be sufficient. It sounds to me like I need to ask another electrician to look at it?

I could repurpose the neutral to be the ground as you suggested--I hadn't thought of that. Since the system is 220, the neutral is currently serving no purpose.

 

[gwegan]

Using the insulated neutral as a ground is a better option. You may want to put green tape on either end. You want an insulated ground back to service entrance panel grounding bar. For those watching at home this is not something you would normally do but it appears to work here because the only connection between neutral and grounding would be at the service entrance.

Bonding the pool would significantly increase the safety of the pool.

 

[bluesmoke]

I agree with danpik it sounds like there is some confusion or miscommunication. It's possible to your electrician didn't understand the difference between bonding and grounding, but in CA there are lots of pools so he should be familiar.

There should be a bare copper wire connecting your pool equipment this should be visible and not in any conduit. It will connect to the outside of the equipment. This is the bonding wire and we'll assume that it's there and hooked up correctly. Inside the actual conduit to your pump motor, for 220v there needs to be two hot wires that provide power. Those hot wires will usually be black,red,blue or orange. By code there has to be another wire in the conduit with insulation and it should be green. This connects to the green screw on the motor and is the only ground. Back at your timer or panel that green wire will connect to other greens.

If your motor was wired for 120V properly, then it should have had 3 wires going to it, black or red etc., white or grey etc. and a green insulated or bare wire. If it doesn't have that, it wasn't wired correctly.

Now for a solution, if there truly is no insulated green wire and you re-wire that motor to 220V, then you can re-use the white wire as danpik suggested. To do that, hook both black/red or hot wires to the separate terminals on the motor for power, connect the white to the green ground screw. Inside your box or timer, disconnect that white wire only and hook it to the other greens usually in a wire nut. Take green electrical tape and go up that wire as much as possible to signify to others that it is now a ground. If you don't have an extra hot wire you can't wire that motor at 220v. If you don't have 3 wires and it's 120V then that was wired wrong and the wires have to be re-ran.

As far as I'm aware, there is no other way to do this, the code is clear and has been this way for a very long time. Running a new ground rod will still require you to run insulated green wire to your pool panel, timer and to all your motors/ pool equipment if it doesn't already exist. I guess you could run a separate conduit to each of the items with just a green insulated wire, but that would be expensive.