Can you leave elements submerged overnight?

[grathan]

So we never really discussed why hot water heaters don't need gfci. Any ideas?

 

[LordUlrich]

So we never really discussed why hot water heaters don't need gfci. Any ideas?

With a hot water heater you are not standing in the water, so the risk of a ground fault through you is greatly lessened.

 

[kevreh]

Check out this thread for a humorous read (it gets pretty heated):

http://www.contractortalk.com/f5/wh...e-gfci-breakers-electric-water-heaters-65559/

Seems like the conclusion is a) the water heater elements are protected by the ground back to the panel, b) most plumbing systems have the metal pipes grounded as well, and c) water isn't as conductive as other things (ie. ground pipes).

But hey, its one thread. I get the feeling that the point of gfci's is to protect humans from making human mistakes, whereas a water heater is professionally installed and grounded. In the electric brewing world, generally speaking having a proper ground is safe. The point of gfci is an extra level of insurance considering we're wiring things that are exposed to a wet environment. I doubt that craft breweries that use electric for heating use gfci. OTOH they have strict local and state safety codes they have to comply with, not to mention the inspections that go along with them.

Now stop worrying about water heaters and address the problem you have.

 

[ScubaSteve]

It's probably because of all the reasons listed above...plus it's a piece of stationary equipment. Equipment does use gfci, especially industrial stuff but it is design to protect wiring, etc. from overcurrent/damage and it trips far above 5 miliamps which is considered the lethal current exposure for humans.

 

[lschiavo]

They are wired in series. The top one takes precedence because that is where the hot water comes out. Once the top thermostat is satisfied it provides power to the bottom. It turns on if needed. Once the top cools off, like you are in the shower, it takes control back and kicks on the top element.

You got it right except the series part. The elements are wired parallel but controlled just as you described.

 

[lschiavo]

So we never really discussed why hot water heaters don't need gfci. Any ideas?

First off, it is a cold water heater. If the water were already hot we would have no reason to heat it. "Water heater" works for me

I think it was said but a water heater is an appliance. It is tucked away in a utility room or basement and is rarely even touched. Metal water lines are the best source of ground in a house. They are a required electrode when available. A properly bonded/grounded water heater poses no risk because it IS "ground". It should be the point that your GFCI receptacles use as reference.

 

[processhead]

First off, it is a cold water heater. If the water were already hot we would have no reason to heat it. "Water heater" works for me

I think it was said but a water heater is an appliance. It is tucked away in a utility room or basement and is rarely even touched. Metal water lines are the best source of ground in a house. They are a required electrode when available. A properly bonded/grounded water heater poses no risk because it IS "ground". It should be the point that your GFCI receptacles use as reference.

Metallic water lines are a good electrical ground because they are required by code to be bonded to the power company ground rod, usually at the meter, and not because they come by it naturally.

Were it not for being bonded back to the power utility ground rod, they might, or might not, be a good, reliable earth ground.

This bonding is done to prevent water lines from accidentally being energized if they were to make contact with an energized conductor anywhere in the home.

Having electrically energized plumbing fixtures is a definite health hazard, which is why they are required to be grounded.

PEX, PVC, or other plastic plumbing systems are treated differently.

Wait a minute, I thought we were talking about cold water heaters?

 

[lschiavo]

Metallic water lines are a good electrical ground because they are required by code to be bonded to the power company ground rod, usually at the meter, and not because they come by it naturally.

Were it not for being bonded back to the power utility ground rod, they might, or might not, be a good, reliable earth ground.

This bonding is done to prevent water lines from accidentally being energized if they were to make contact with an energized conductor anywhere in the home.

Having electrically energized plumbing fixtures is a definite health hazard, which is why they are required to be grounded.

PEX, PVC, or other plastic plumbing systems are treated differently.

Wait a minute, I thought we were talking about cold water heaters?

Around here at least, the power company does not provide a ground. Only two hots and a neutral. Ground is established at every service by bonding the neutral to water lines, ground rods, ground rings and such. A buried metal water line sometimes hundreds of feet long is about the best ground you can find. Bonding the neutral ties the three wire system to a reference point for that service entrance hence the safety benefits you mention.

 

[Hermit]

You got it right except the series part. The elements are wired parallel but controlled just as you described.

My bad. I guess I was focused on the control path. I've been gas for the past 22 years.

 

[grathan]

Wouldn't metal drain pipes go to ground as well?

 

[floormatg]

Yes, it technically could be used, however it would violate electrical code, and the ground clamps used for piping that size are extremely expensive. A ground clamp for 1/2" up to 1" pipe is about 5$. When you jump to 1 1/4" ground clamp the price jumps to about 50$ each.

Also, some meters like the Fluke T5-1000 only measure resistance up to the 1000 ohm range.

Relying only on a breaker and not a GFCI to protect you in case of a ground fault is plain stupid, and what we in the electrical trade would call natural selection. If there is an electrical fault to ground, the breaker may not trip (for a handful of reasons) and still create a shock hazard. Use the GFCI and don't disconnect the ground. By tripping, it is doing it's job.

You said their is a ground lug on the GFCI... What brand/model is it? I've connected quite a few GFCI's and never seen one with a ground terminal; usually only 2 hots and a neutral. However even if this is the case, it probably wont fix your problem.

Replace the element, don't risk your life with electricity.

 

[grathan]

Yes, it technically could be used, however it would violate electrical code, and the ground clamps used for piping that size are extremely expensive. A ground clamp for 1/2" up to 1" pipe is about 5$. When you jump to 1 1/4" ground clamp the price jumps to about 50$ each.

Also, some meters like the Fluke T5-1000 only measure resistance up to the 1000 ohm range.

Relying only on a breaker and not a GFCI to protect you in case of a ground fault is plain stupid, and what we in the electrical trade would call natural selection. If there is an electrical fault to ground, the breaker may not trip (for a handful of reasons) and still create a shock hazard. Use the GFCI and don't disconnect the ground. By tripping, it is doing it's job.

You said their is a ground lug on the GFCI... What brand/model is it? I've connected quite a few GFCI's and never seen one with a ground terminal; usually only 2 hots and a neutral. However even if this is the case, it probably wont fix your problem.

Replace the element, don't risk your life with electricity.

I think you've misunderstood me. I didn't say the gfci had a ground lug.

Also I didn't mean the drain pipe as an intentional ground, but more as accidental. As in when someone was showering and the fault chose to go that way instead of back to the panel.


I do plan to replace the element or at least pinpoint it as being faulty.

 

[floormatg]

**update**

Minor progress today. Ripped everything apart and rewired using 12ga instead of 8ga. Problem with tripping out persisted. BUT. I had a thought to try removing my ground wire from the kettle. And the tripping stopped. So now I just need to figure out if I need that ground wire or not, and if so where I went wrong wiring it up. Anyone have any thoughts on this?


The details of my ground is 200 amp panel in the main house uses a 100 amp breaker to feed the garage panel. (4 strand with ground going back to 100 amp breaker in 200 amp panel). And then the kettle gets hooked to the ground lug on the 50 amp gfci in the 100 amp panel.

My mistake, I guess I'm not reading that properly.

How do you plan to pinpoint it being faulty? Just curious. Personally I would just disconnect the 2 hots from the element and tape them up to insulate them and turn the power on. If it doesn't trip, then you've pinpointed it to the element.

Also I didn't mean or it to sound like I was attacking you, just putting it out there for others who may read this thread.

 

[grathan]

Thanks I'll try that.

Weird that I said ground lug on the breaker. I'm pretty sure there was only 2 hots and 2 neutrals. Homeline that Home Depot sells. I think I have the ground going back to the ground rail in the panel which is separate from the neutral rail.