confused with what's going on, ground/neutral issues, tripping GFCI etc. 1

[michaelwoodcoc]

I'm not an electrical engineer but I thought I'd get better responses here than if I posted in the hobby section.

I'm having a strange issue and I'm a little tired to get my head weapped around it for the night so I figured I'd ask before I jump on it tomorrow.

My shed has a sub panel coming off a sub panel for the hot tub which is run off a GFCI breaker in the main panel. When the ground rod is connected in the shed, the GFCI trips. No ground rod, it doesn't trip.

I can measure .1 volts from either leg to the ground rod at the shed. I figured something wierd might be happening like my shed was conducting ground current from the house to the rod.

I pulled on the wire from the meter box to the ground rod and the wire just came out of the ground.

Also the main panel is not grounded like I'd prefer to see, but if it's supposed to be grounded at the meter that's fine I guess but it was not grounded at the meter, and the wire they used seems inadequate compared to the wire (#8 I think) that I used for the shed.

I had one ground rod left from the shed that has not been finished and I pounded it in near the meter box and grounded that wire for the night. GFCI still tripped but the ground rod by the shed is in much more moist soil so it's more conductive.

Much of the glaring problems I've already fixed. The wires from the spa panel to the shed are now THWN run in water right conduit, no rommex in conduit. Some I have yet to fix.

I'm just curious, is there something I'm totally overlooking here? It seems like I should not have the GFCI tripping, but I also need two ground rods for the main panel, can I just do that at the meter or do I need to have the panel attached directly to the ground rods?

Engineering student. Electrical or mechanical, I can't decide!
Minoring in psychology

 

[LionelHutz]

The problem appears to be rather simple. The hot tub panel has NO ground wire from the main panel. That bare conductor is being used as a neutral, you can see it connecting into the bottom of the GFCI breaker in the main panel. Yet, the neutral bus, assuming it is a neutral bus, is being used for both grounds and neutrals.

What possibly happened was that the spa panel was 240V only since the spa would have needed only 240V and no neutral. Then, the spa was removed and there was this "free" panel so someone decided to re-purpose the spa panel to feed other stuff. This required repurposing the ground conductor as a neutral, which is wrong and should never have been done.

The proper solution is as follows.

Run a 3 conductor cable to the spa panel with red, black, white and bare ground conductors.
Make sure the spa panel neutral bus is isolated from the enclosure body.
Install a ground bar screwed to the spa enclosure box for the ground wires to all attach to.

The correct ground bar that should have come with that spa panel would have likely screwed to those open holes at the left in the panel.

Overall, it's a big wiring mess.

How does that conduit with THWN get to the spa panel? I don't see any conduit there.

I see wires running out of the spa panel that are not armored or in conduit. I'm assuming the spa panel is on an outside wall of the house so none of those are allowed.

I also believe any sub-panel in another building needs a main breaker.

Hate to hear he passed, but if the electrician did the previous spa panel work then you didn't want him back.

 

[Palletjack]

Entire problem amounts to an incorrect installation as mentioned earlier. The sub panel is wrong.

 

[itsmoked]

They sell ground bar kits at Home Despot.

Keith Cress
kcress -

http://www.flaminsystems.com

 

[LionelHutz]

I'm running cat6 to the shed for two or three security cameras. I've heard there can be issues with different, or maybe it was the same ground, for network connections. If that's the case I'll do whatever is best for the network.

For this you would be far better off running fiber. More expensive, but only until the CAT6 run results in damaged equipment in your house.

 

[RedSnake]

My shed has a sub panel coming off a sub panel for the hot tub which is run off a GFCI breaker in the main panel. When the ground rod is connected in the shed, the GFCI trips. No ground rod, it doesn't trip.

The GFCI is not connected to ground and does not care if the system is grounded.
The GFCI looks at the current balance between the hot(s) and neutral and if it sees an unbalance it assumes that some current is going where it should not and trips.

If a GFCI is mandated by the code, as for a hot tub and possibly lights and receptacles near the hot tub, then the GFCIs must be the lower rated GFCI.

Waross is right here!
As long as you do not install the earth rod and connect it to what we call PEN leader (Protected Earth and Neutral leader) in your sub panels the GFCI will work and protect you as it should, until you can fix your electrical system properly.
I would suggest without knowing what the electrical laws look like with you, that you install earth fault circuit breakers for personal protection 50mA anything over 50mA is for fire protection for all electricity but especially sockets and installetions used outdoors, even if it is not a requirement, it is a cheap life insurance.

New electrician wanted.
Preferably someone with experience this time.

Take care and be safe! Anna

“Logic will get you from A to Z; imagination will get you everywhere.“
Albert Einstein

 

[waross]

In Canada the code mandates life safety GFCIs for some locations and applications.
The code specifies that the GFCI must trip at between 4 ma and 6 ma. Nominal 5 ma GFCI.
That is what is available.
For ungrounded and impedance grounded power circuits over 1000 Amps or 2000 Amps the code may require ground fault detection trip.
Trip tatings may be as high as 1200 Amps. (A not ma)
This may require CTs, sensors, ground fault relays, and/or contactors.
The cost and complexity of these equipment protection ground fault systems are far beyond anything that a homeowner would need or even consider.
Suggestions of GFCIs at any other than 5 ma are not realistic in North America.
I am aware that in other countries, GFCI breakers with 30 ma trips and similar ma rated trips are readily available but for a hot tub in North America the law is 5 ma trip.

Bill
--------------------
"Why not the best?"
Jimmy Carter

 

[RedSnake]

I will correct myself here in SE for housing it is > 30mA personal protection and > 300mA for fire.
What is required in the United States I do not know.

BR A

“Logic will get you from A to Z; imagination will get you everywhere.“
Albert Einstein

 

[waross]

In Canada, and while I don't have a copy of the NEC, Canada and the US use the same breakers:
Greater than 4 milli-amp and less than 6 milli-amp for personal protection or life safety. Nomimal 5 ma.
For fire and equipment protection; up to 1000 AMPs at less than 150 Volts or 1200 Amps at over 150 Volts.

Bill
--------------------
"Why not the best?"
Jimmy Carter

 

[MacGyverS2000]

1000/1200 Amps seems... well... unsafe for practically any equipment, barring a dam's generating station

Dan - Owner

http://www.Hi-TecDesigns.com

 

[LionelHutz]

Most new low voltage systems installs in North America are solidly grounded and a ground fault on a 1000A+ system will easily pass the 1200A maximum trip level.

 

[FacEngrPE]

In the US the choices are
Ground Fault Circuit Interrupters (GFCI) (5mA)
Ground Fault Equipment Protection (GFEP) (30mA)

The GFCI is suitable for protecting people from electrocution hazards.

https://www.osha.gov/SLTC/etools/construction/electrical_incidents/gfci.html

The GFEP does a good job of preventing electrical fires (like when heat trace gets wet) but do not trust a GFEF to protect people in a wet location.

Both of these work on differential current between the supply and return.

 

[VladChiefns830]

I didn't know that thin mulch was a code-compliant burial method. I'm guessing Florida. Last time I checked, the table was for 0 - 1000 volts. I tried to get this addressed by Code Panel 5, but they rarely listen to inspectors.

Seriously, this looks like a nightmare and there are multiple violations all over. Since water and electric tend not to mix well, I would recommend getting at least a licensed electrical contractor (a good one) to clean everything up. Don't go with the cheapest bidder. That's my 2-cents.