Ground / Bonding protection?...

[1793]

I have a topic on another section of this forum about H2-O heater and breaker. Now I would like to get the opinion of those on this portion of my problem.

In my neck of the woods in older installations we have a separate electric meter for the water heater. This is where my question comes into play. I have thought about just changing the FPE breaker in the 2 circuit MLO panel controlling this H2-O heater but I'm not happy about this option. The FPE is very expensive around $90.00 for a Double Pole. The ML panel is fed from this other meter and I’m concerned about the grounding / bonding. To help as much as I can, this small panel is fed with #10 in ?” EMT. There are only two wires in this conduit.

Does this second panel have any EG protection from the main service through the conduit connections?

Should I make a physical “tap” to the water ground from the main service panel for this panel, or come off the grounding bar with an EG to the water heater panel about a foot away?

I thinking of replacing this FPE with something newer and putting it on a main breaker panel. There is no room in the service panel for this water heater to be moved there.

I hope someone can make sense of this and offer a suggestion or two.

PS the HO will be making a big change to this house next spring and at that time we will more than likely go through a Service Upgrade.

Thanks

 

[George Stolz]

Can you describe this in more detail? How many meter enclosures, how many panels, how they relate, etc.?

It sounds like the conduit itself is serving as the neutral path.

 

[iwire]

It sounds like the conduit itself is serving as the neutral path.

A 'neutral' is not really needed as the water heater is straight 240.

The typical set up here was two meters in one common meter socket each supplying a service disconect inside. The grounded conductor is brought to both service disconnects.

The off peak service had a time clock that shut down the water heater during peak usage times.

As far as the OP I would say you need to bring the grounded conductor into the off peak disconect just for enclosure bonding purposes.

 

[George Stolz]

Is that typical for houses out east?

 

[iwire]

Is that typical for houses out east?

It used to be, you paid a much lower rate for the off peak meter.

At this point I do not think any local power company offers this option. Homes get one rate one meter.

 

[ryan_618]

Its common here for Air Conditioning equipment. I can testify that my power bill is less than it was before I agreed it.

 

[dlhoule]

Its common here for Air Conditioning equipment. I can testify that my power bill is less than it was before I agreed it.

Is that off a timer or a radio control? Here we have separate meters for both A/C and HW that are radio controlled. Typically they will not be off for more than 20 minutes at any given time.

 

[1793]

Can you describe this in more detail? How many meter enclosures, how many panels, how they relate, etc.?

I will try to get by this morning and take a few photos and get them posted today.

 

[1793]

Below is a photo of the meter configuration. There is one service panel, 200a. Then off of the main meter is a second meter feeding a 2 circuit MLO panel / disconnect for the water heater.

I'm concerned about the grounding/bonding of this heater panel.

 

[hillbilly]

(IMHO) You need to insure that the bond between the water heater panel to the grounded service conductor is adequate.
If those EMT fittings are made up tight, it will certainly make it a better bond, although it's not adequate to serve as the bonding conductor required by 250.92 because of (250.92(B). The bonding conductor that you need to run is sized according to 250.66. If it were me doing the work, I would bond from the water heater panel grounding bar to the main panel grounding bar, and assume that the meter base is OK because it is old and probably met code when installed. Make sure that the grounding bar in both panels are bonded to the enclosures, Does the wiring from the panel to the Water heater have a EGC? If not, it is sized according to 250.122.
steve

 

[1793]

(IMHO) ...Does the wiring from the panel to the Water heater have a EGC? If not, it is sized according to 250.122.
steve

The line feeding the Water Heater now is BX, inspection sticker is year 1966. I will be changing this 12 with 10/2 Romex.

 

[1793]

(IMHO) ...The bonding conductor that you need to run is sized according to 250.66. ...
steve

Are you using the main service,200amp #4 for your conductor size or the small panel 30amp #8?

 

[hillbilly]

If the bonding jumper is installed on the supply side of the service disconnect, it must be sized according to table 250.66. From the pictures, it looks like what you have. Read 250.92 and 250.102(C).
steve