Existing Main - No Mfr Sticker

[SolarBill]

1st post, so will try to make sure I'm to the point and appropriate. I have already searched the PV Threads for this topic, but haven't found this specific issue.

We have a customer with an older Murray/Siemens 12/24 with what we believe to be 100A bus (based on Service Disconnect OCPD 100A), the inspector has given us the correction "Existing panel is not labeled – plans call for 100A panel which cannot be verified – Solar breaker usage in this panel cannot be verified". Is there any code or guidance for inspectors to determine bus rating? We always were under the assumption (yes I know what I'm doing when I assume), that if there is no Manufacturer's Label/Sticker then we assume the bus is the same as the Service Disconnect. We are trying to connect a 2-pole 20A backfeed breaker, but he won't give me the final without upgrading the main and we don't want to put the customer through another $1500-2500 if there is some way to get it final'ed without.

Any ideas or guidance?

 

[petersonra]

1st post, so will try to make sure I'm to the point and appropriate. I have already searched the PV Threads for this topic, but haven't found this specific issue.

We have a customer with an older Murray/Siemens 12/24 with what we believe to be 100A bus (based on Service Disconnect OCPD 100A), the inspector has given us the correction "Existing panel is not labeled – plans call for 100A panel which cannot be verified – Solar breaker usage in this panel cannot be verified". Is there any code or guidance for inspectors to determine bus rating? We always were under the assumption (yes I know what I'm doing when I assume), that if there is no Manufacturer's Label/Sticker then we assume the bus is the same as the Service Disconnect. We are trying to connect a 2-pole 20A backfeed breaker, but he won't give me the final without upgrading the main and we don't want to put the customer through another $1500-2500 if there is some way to get it final'ed without.

Any ideas or guidance?

if the plans call for 100A panel you need to show there is a 100A panel there.

Why would it cost $1500-2500 to replace the guts of a 100A panel?

 

[SolarBill]

if the plans call for 100A panel you need to show there is a 100A panel there.

Why would it cost $1500-2500 to replace the guts of a 100A panel?

I understand that, this was most likely a Murray/Siemens 100A 1Ø3W 240V 12/24 Main Service Panel. The manufacturer label is missing (the one that dictates bus ratings, AIC, lug sizes, etc.), we do not want to do an MSP Upgrade at $1500-2500 as we would have to replace and I think current code states min sizing to 200A service now. Nonetheless we are trying to see if there is anything that states that if for existing equipment, missing manufacturer label, to determine applicable bus rating to go based off the Service Disconnect as I don't know anyone that reprints old manufacturer labels(which wouldn't matter as he has already seen it). If there is nothing we can do we will have to replace the MSP and I'm sure the customer doesn't want to take the hit on this either.

 

[petersonra]

I understand that, this was most likely a Murray/Siemens 100A 1Ø3W 240V 12/24 Main Service Panel. The manufacturer label is missing (the one that dictates bus ratings, AIC, lug sizes, etc.), we do not want to do an MSP Upgrade at $1500-2500 as we would have to replace and I think current code states min sizing to 200A service now. Nonetheless we are trying to see if there is anything that states that if for existing equipment, missing manufacturer label, to determine applicable bus rating to go based off the Service Disconnect as I don't know anyone that reprints old manufacturer labels(which wouldn't matter as he has already seen it). If there is nothing we can do we will have to replace the MSP and I'm sure the customer doesn't want to take the hit on this either.

I never heard of a minimum 200A service for a dwelling.

If you cannot document the panel has 100A bus you may well have to replace it.

 

[Sierrasparky]

I never heard of a minimum 200A service for a dwelling.

If you cannot document the panel has 100A bus you may well have to replace it.

CA requires a 200 amp panel and be solar ready , don't remember if that applies to a change out.

I understand that, this was most likely a Murray/Siemens 100A 1Ø3W 240V 12/24 Main Service Panel. The manufacturer label is missing (the one that dictates bus ratings, AIC, lug sizes, etc.), we do not want to do an MSP Upgrade at $1500-2500 as we would have to replace and I think current code states min sizing to 200A service now. Nonetheless we are trying to see if there is anything that states that if for existing equipment, missing manufacturer label, to determine applicable bus rating to go based off the Service Disconnect as I don't know anyone that reprints old manufacturer labels(which wouldn't matter as he has already seen it). If there is nothing we can do we will have to replace the MSP and I'm sure the customer doesn't want to take the hit on this either.

SolarBill , Have you tried to look in the neighborhood for the same panel on someone elses home?

I did that for a friend. Took a picture of the label and the panel showed to the inspector. Printed the picture and glued it to the panel cover.
Heck it might be a 125 amp buss.
Sometimes you can get a part number and get labeling from the supply house.

 

[jaggedben]

The AHJ is being a jerk. Of course it's a 100A panel if it has a 100A main. Have you ever seen a 12/24 panelboard that was rated less than 100A? I've done what you did a few times without problems.

You do not have to upgrade amperage, just replace with 100A.

Try what Sierra said about the neighbors, that's worked for me.

Replacing the guts might be a good idea if you can find appropriate ones, but run it by the AHJ.

 

[electrofelon]

The AHJ is being a jerk. Of course it's a 100A panel if it has a 100A main. Have you ever seen a 12/24 panelboard that was rated less than 100A? I've done what you did a few times without problems.

You do not have to upgrade amperage, just replace with 100A.

Try what Sierra said about the neighbors, that's worked for me.

Replacing the guts might be a good idea if you can find appropriate ones, but run it by the AHJ.

I Agree. Even those small 6/12 homeline or QO panels are 100 Amp. I dont think you will find anything less than 100 until you get down to some of those little 2-3 space circuit breaker enclosures. And especially if it has a 100 amp breaker factory installed. If its a MLO with a backfed 100, and the inspector isnt real familiar with panelboards/loadcenters then maybe I would understand.

 

[andrew.tkelly]

I agree with jaggedben. The inspector is being extremely rigid --perhaps he is new. If using the rating of the neighbor's main panel as evidence does not work, I would try to appeal to the chief inspector, or whoever the head of that department is (or maybe reach out to another inspector, if possible). He's being unreasonable, in my opinion. I would highly doubt that the rating is under 100A if the main breaker is 100A.

Andy

 

[jaggedben]

Another thing to check: If there's any record of when the service was installed and approved, and the 100A code minimum for a single-family home was in effect at the time, that's a strong argument it was rated 100A.

 

[BillK-AZ]

I am dealing with a similar problem. Approximately 1995 C-H center fed main all-in-one panel without any label except a UL sticker that according to C-H (now Eaton) technical support does not trace to a specific model. AHJ says that it may have two 100A busses and we need to show that it has 200A busses. Emailed photos to Eaton 4 days ago, no response yet. Oldest catalog I have is 2010 and it does not have similar panels.

I measured the buss bar and it is 9/16" x 3/16". A table on the Copper Development Association website (copper.org) indicates that 1/2" x 3/16" is rated for 195A at 30°C temperature rise, so 9/16" x 3/16" buss bar should be 219A.

If I do not get a response by Eaton in a few days, I will try to get the AHJ to accept that this panel has 200A buss bars.

Anyone been able to have the AHJ accept simple measurements and a standard table for establishing ampacity?

 

[Sierrasparky]

I am dealing with a similar problem. Approximately 1995 C-H center fed main all-in-one panel without any label except a UL sticker that according to C-H (now Eaton) technical support does not trace to a specific model. AHJ says that it may have two 100A busses and we need to show that it has 200A busses. Emailed photos to Eaton 4 days ago, no response yet. Oldest catalog I have is 2010 and it does not have similar panels.

I measured the buss bar and it is 9/16" x 3/16". A table on the Copper Development Association website (copper.org) indicates that 1/2" x 3/16" is rated for 195A at 30°C temperature rise, so 9/16" x 3/16" buss bar should be 219A.

If I do not get a response by Eaton in a few days, I will try to get the AHJ to accept that this panel has 200A buss bars.

Anyone been able to have the AHJ accept simple measurements and a standard table for establishing ampacity?

How about a picture?

 

[pv_n00b]

There is a lot of variability on this with AHJs but the inspector is well within their job description to call out any problems they see during an inspection. If they see damaged or non-functional equipment, equipment that has been modified or degraded, equipment that would not meet the code requirements in effect when it was installed, or any unpermitted work they can call it out and write it up. So if the labels are gone or painted over and that would have prevented the panelboard from meeting code when first installed they can require replacement. So while it causes more work when this happens I can't fault the inspector for wanting to do their job. Keep in mind their job is safety and equipment is only seen when first installed and when any additional work is done, and that could be 20 or 30 years later.

 

[jim dungar]

Anyone been able to have the AHJ accept simple measurements and a standard table for establishing ampacity?

Bussing in equipment like breaker panels is done by heat rise testing through the NRTL. instead of using dimensions.
The buss bar table is for conductors in free air not ones crammed in behind beakers, field wiring, and bus connection fingers.

 

[BillK-AZ]

How about a picture?

 

[Sierrasparky]

View attachment 20266

Nice but you are not solar bill!

 

[pv_n00b]

I am dealing with a similar problem. Approximately 1995 C-H center fed main all-in-one panel without any label except a UL sticker that according to C-H (now Eaton) technical support does not trace to a specific model. AHJ says that it may have two 100A busses and we need to show that it has 200A busses. Emailed photos to Eaton 4 days ago, no response yet. Oldest catalog I have is 2010 and it does not have similar panels.

I measured the buss bar and it is 9/16" x 3/16". A table on the Copper Development Association website (copper.org) indicates that 1/2" x 3/16" is rated for 195A at 30°C temperature rise, so 9/16" x 3/16" buss bar should be 219A.

If I do not get a response by Eaton in a few days, I will try to get the AHJ to accept that this panel has 200A buss bars.

Anyone been able to have the AHJ accept simple measurements and a standard table for establishing ampacity?

The problem is that the bus rating is not just based on the physical size of the bus. The bus rating is also limited based on the thermal effects in the panel. That is all covered by the standard.

 

[BillK-AZ]

Friends with contacts at Eaton finally got an answer.
This is a 200 amp style device CG32M2S24 manufactured in Lincoln, IL during 1994 based on the date code label F450=
The original UL File E8741 Vol. 4 description of what you have is shown below.
The main breaker installed was a CH2200X, mounted onto a panel that included our 200 amp bus construction.
The below shows this to be a 200 Amp, 120/240 volt, 32 circuit.

 

[kwired]

The AHJ is being a jerk. Of course it's a 100A panel if it has a 100A main. Have you ever seen a 12/24 panelboard that was rated less than 100A? I've done what you did a few times without problems.
I also agree with that, and would even go as far as saying most probably are even 125 amp rated bus, just that one with a factory installed 100 amp main may only be labeled as 100 amp

I Agree. Even those small 6/12 homeline or QO panels are 100 Amp. I dont think you will find anything less than 100 until you get down to some of those little 2-3 space circuit breaker enclosures. And especially if it has a 100 amp breaker factory installed. If its a MLO with a backfed 100, and the inspector isnt real familiar with panelboards/loadcenters then maybe I would understand.

Can't say for certain on the Homeline - the QO I know is 100 amp bus - but has max individual branch circuit rating of 70 amps.