Electric sub-panel

May 15, 2015
18
0
MA
#1
Hi All-

I will be replacing my GFCI with a sub-panel to power my new VS pump and heat pump. Can anyone tell me if the sub-panel requires grounding to rods, similar to your main house panel? The sub-panel will be located in a shed down by the pool. I'm seeing different responses across the web. I'm thinking of doing it regardless.

Also, any reason NOT to attach the bonding wire to the rods? I have a 8 awg copper wire around the pool buried in 1-1/2" crushed stone. I understand it's suppose to be 4-6" deep and assume this means dirt, not stone. Would attaching this wire to the grounding rod meet the buried wire's intent? Assuming it has to be in dirt? The intent being to bond the earth.

If the sub-panel requires rods, the ground will be indirectly bonded via the panel anyway. The panel will be about 8' from the pool.
 

Bama Rambler

Mod Squad
LifeTime Supporter
TFP Expert
Jun 23, 2009
22,793
4
105
SouthWest Alabama
#2
The sub panel should not be grounded at the panel. It's grounded at the main panel.

Tying the bond grid to a ground rod, while not prohibited, won't do what you're hoping. The reason for the bond loop to be buried in the dirt around the pool is to keep the surrounding earth at the same potential. It relies on the conductivity of the earth contacting the wire to do that, so attaching the wire to a ground rod only affects the earth surrounding the ground rod.
 
May 15, 2015
18
0
MA
#3
The sub panel should not be grounded at the panel. It's grounded at the main panel.

Tying the bond grid to a ground rod, while not prohibited, won't do what you're hoping. The reason for the bond loop to be buried in the dirt around the pool is to keep the surrounding earth at the same potential. It relies on the conductivity of the earth contacting the wire to do that, so attaching the wire to a ground rod only affects the earth surrounding the ground rod.
Perfect; thank you. Out of curiosity, when would a sub-panel be grounded at the panel, or is this never required? Also, since the bonding wire is below the stone and any person in the area would be in contact with the stone only, do you feel burying the wire below the dirt is necessary? From a safety perspective.
 

Melnic

Silver Supporter
Jun 7, 2017
205
0
Maryland
#4
FYI there are both National and local electric codes to follow. You can follow the advice here on The NEC (National Electric Code) but you may have to research local codes on grounding.

In my county/state they adopted the NEC than added stuff onto it. As I have traveled the country for Car Wash installations over the years I have seen plenty of what I thought strange grounding schemes and codes but as I talked to the locals came to understand why they do it that way.

My sub panel ground comes from my main breaker panel( one of the 2 I have)
I am not sure why but they actually ran 2 ground wires. I have not traced if both go to the sub panel or not.
 

jza1736

Silver Supporter
Apr 22, 2017
536
0
Greenlawn, NY
#6
Grounding Electrode Required

When applying the grounding and bonding rules for multiple buildings, one must verify that both performance functions are met and are in concert with the requirements of the NEC. As the feeder arrives at the separate building or structure, several NEC rules must be applied. Rules for separate structure disconnecting means and their locations must be applied. Generally this is also where the initial or first grounding and bonding connections will be made. The NEC requires that a building or structure supplied by a feeder or branch circuit must have a grounding connection through the available grounding electrode or grounding electrode system at that building or structure. Basically this required grounding electrode is the same for this building or structure whether a service or a feeder supplies it. It must have a grounding electrode(s). The grounding electrode system must be made up of the specified electrodes in Part III of Article 250.
 

PoolguyinCT

In The Industry
Jul 22, 2014
2,660
0
Connecticut
#7
Grounding Electrode Required

When applying the grounding and bonding rules for multiple buildings, one must verify that both performance functions are met and are in concert with the requirements of the NEC. As the feeder arrives at the separate building or structure, several NEC rules must be applied. Rules for separate structure disconnecting means and their locations must be applied. Generally this is also where the initial or first grounding and bonding connections will be made. The NEC requires that a building or structure supplied by a feeder or branch circuit must have a grounding connection through the available grounding electrode or grounding electrode system at that building or structure. Basically this required grounding electrode is the same for this building or structure whether a service or a feeder supplies it. It must have a grounding electrode(s). The grounding electrode system must be made up of the specified electrodes in Part III of Article 250.
Great post.. I have a feeling you pull wires all day??
Ray