Sup panel question?

[jlybolt]

First picture is panel bank of meters. Before the meters there is a panel with one breaker controlling power to building. Would this panel be considered the main disconnect panel thus requiring all other downstream panels to have ground / neutrals isolated. There is also subpanels inside of the units.

[Bruce A. King]

The first point of disconnect is the service equipment.
So the panels below the meters should have neutrals floating.
The local AHJ might have let it go due to the setup there.
I would note it and rec. it be further evaluated.

[jlybolt]

You mean he might have let it slide by because the first panel is before the meters?

[Bruce A. King]

Also because of the short distance between these exterior panels.
What year was this installed?

[jlybolt]

House was 1985 built. Subpanel in the dwellings looked nice except for the water heater breaker that felt hot to the touch compared to other breakers.
I am still debating it to wright it up and as hot spot or not.

[Doug Edwards, CMI]

No debate. Always err to the side of caution.

[Bruce A. King]

hot or warm? A 220V breaker such as a water heater that has been heating for about an hour will feel warm, no problem, but hot is a problem. About 100 to 105 degrees would be normal with ambient around 80 to 85.

[Jeffrey R. Pope]

Based on what I can see, and your description, I would call this improper.

It may all be considered (arguably) components of the service equipment and therefore not need to be changed. But I see it as separate components that require correction.

Additionally, from what I understand, there should be no disconnect located prior to the meter (as illustrated in figure 230.1 for services). So by removing the switch/breaker prior to the meters, this setup would be okay.

[jlybolt]

Bruce, temp was 120 degress as measure with my infared laser meter. The rest of them were around 95 to 100 degrees.

Thanks everyone for your help. I will recommend further evaluation of the service equipment issue.
This is the first time that I have seen a panel disconnect before the meter. Hope I dont see too many of these.

[Pierre Belarge]

Installing a disconnect before the meters is not an NEC violation. It may or maynot be permitted by the POCO.

The meters on the load side of the disco in this picture would typically require an isolating neutral kit, but there is an exception in the NEC that permits this.


The panels under the meters need to have the neutrals and Equipment grounds separated.


Remember something about the temperature of conductors and circuit breakers...
Take a look at Table 310.16. At the top of the table, you will see the temperature ratings of each column. Notice the 75 degree C column, it is also 167 degrees F.
For the water heater, if an 8 AWG conductor was installed, and the load is 50 amps, the conductor will (due to the current flowing) possibly reach a temperature close to 167 degrees F. Obviously warmer than can be touched. So a high temperature is not always an issue, what is causing the high temperature could be an issue.

[Jeffrey R. Pope]

Originally Posted by Pierre Belarge

The panels under the meters need to have the neutrals and Equipment grounds separated.

I never found anything prohibiting this type of installation, but if the disconnect is allowed prior to the meter, then I would certainly agree with this statement. . .

[jlybolt]

Is it possible that at one time the panel before the meters was meant to be a house panel (panel suppyng electricity for the non tenant systems).
But if this was this the case, wouldnt there also be a meter?

[Paul W. Abernathy]

James,

I am sorry I also will chime in, I have been doing a roof this weekend for my parents and well lets just say I am not as YOUNG and NIMBLE as I used to be.

Their is no violation for the Panel ahead of the "gutter" to which the taps take place for the different meters which are considered feeder meters.

Now I do not have a problem with the main disconnect ahead of the gutter as that is protecting the wires to be tapped and would probably be part of the tap rule they used to complete this installation.

If the main panel is grounded correctly and their is a good bond between the gutter and the meter cabs and such I dont have a problem with it to the meters being 3 wire....However, I could be wrong here but I do not like the idea of the 3 wire SE from the disconnects to the panels located within the facility....

It is in my opinion ( and only my opinion ) that at the FIRST main feeder disconnect they should split at that time and (4) wire be run to the "remote distrbution panels " within the facility.

Now.....I don't do many meter banks these days...but that is how I would do it and have done it in the past......

Now since we can't see behind the feeder main disconnects I can't comment on IF it is run in conduit and they are using that as the equipment grounding conductor....I just can't see through walls but it sure looks like typical SE to me leaving the image to the right.

Hope this helps any....

[Greg Fretwell]

Lift the neutral to be perfectly legal but since this is all a cludge of interconnected service equipment it is a distinction without a difference. They are probably bonded in every meter can too.
They do have a 4 wire feeder to the home and that is where I would get picky about the neutral bus.

[Pierre Belarge]

250.24 Grounding Service-Supplied Alternating-Current Systems.
(A)(5) Load-Side Grounding Connections.
A grounding connection shall not be made to any grounded conductor on the load side of the service disconnecting means except as otherwise permitted in this article.


There are some exceptions, but those exceptions do not pertain to this type of installations, except for...

250.142(B) Load-Side Equipment
Exception No.2 It shall be permissible to ground meter enclosures by connection to the grounded circuit conductor on the load side of the service disconnect where all of the following conditions apply:

(1) No service ground-fault protection is installed.

(2) All meter socket enclosures are located immediately adjacent to the service disconnecting means.

(3) The size of the grounded circuit conductor is not smaller than the size specified in Table 250.122 for equipment grounding conductors.