I followed up on a home inspection report today and opened up a residential 150 Amp 30 ckt panel which contained mostly mini breakers for a total of 34 branch circuits with about 8 full size spaces still open. It was not a "CTL" panel. The home inspection report noted that there was "additional capacity available". The bus diagram on the door only depicted full size breakers (one per space = 30).

Comments, please.

You might check on the label for the "approved" C/Bs to be used with the loadcenter to see if it allows for the use of the minis (AKA junks).
If not, it's subpanel time.
???Is a CTL required where the available fault current is low (<10KA)? (I don't know the answer to this one)

In this case CTL means CircuiT Limiting not current limiting. This is a UL Classification for limiting the number of circuits in a panelboard.

Circuit limiting "tandem" breakers have some type of rejection feature to prevent them being installed in non-CTL panels. "Cheater" breakers do not have these rejectors.

Redsy,
was this concern part of your follow up? can you simply take advantage of the 8 open spaces??

sparky,

I'm mainly just curious about the use of mini breakers in a non-CTL panel and how many breakers can properly be installed. I'm thinking only 30 full size(no minis). Someone could conceivably install 60 mini breakers in this panel.
The reason that I was called in was because the home inspector "recommended the service be upgraded to 200 amp". What his recommendation is based on, I haven't a clue. He didn't say. Now the buyers want a 200 amp upgrade. This was immediately after his remark that "there was additional capadity available". This, I assume was due to the 8 available spaces. I did a calculation for existing dwellings and determined that about 115 amps is adequate for this size home.

I see..I am also curious,
Is 'CTL' clearly defined on the panel stickers? Or is this info purseued via listing?

Redsy,

I never heard of an Inspector requiring a service upgrade without having calculations from NEC Article 220 that would justify such. Calculations from Article 220 would clearly indicate if one was needed.

Sparky: Class CTL means "circuit limiting" See Section 384-15, paragraph 2 in the 1999 NEC:

A lighting and appliance branch-circuit panelboard shall be provided with physical means to prevent the installation of more overcurrent devices than that number for which the panelboard was designed, rated, and approved.

From the UL White Book: "Class CTL panelboards are identified by the words "Class CTL" on the Underwriters Laboratories Inc. Follow-Up Service Listing Mark.

Class CTL panelboards incorporate physical features which in conjunction with the physical size, configuration, or other
means provided in Class CTL circuit breakers, fuse holders, or fusible switches, are designed to prevent the installation of
more overcurrent protective poles than that number for which the device is designed and rated."

I have images showing this information on the equipment.

Yes Joe,
my Q was if the panels are, or are required to be, marked as such.

Frank,

He's not a real electrical inspector. He's one of the "Home Inspection Service" employees. This is a popular concept in recent years in which a home buyer will pay about $300.00 to have someone give a home that they want to buy the once-over. It is just a cursory inspection of the major parts of the home. Often, they recommend a professional tradesman evaluate certain systems furhter. As I said, his "recommended upgrade" seems to be just a thought on his part because he didn't have any basis for it. Problem is, now the buyers are requesting the upgrade. The "existing dwelling" calculation falls well within the existing 150 amp service, so I can honestly say it doesn't need an upgrade. I don't like all these mini breakers in this panel. (He didn't seem to mind them). However, I was called to asses the service capacity only, not the inside of the panel. It's an awkward situation, I wish I hadn't seen the panel.

required and desired are 2 different animals.
the customer is king....

Yes Sparky they are required to be marked as such.



The information above clearly states that fact.


[This message has been edited by Joe Tedesco (edited 12-29-2001).]

Joe,
The panel in question has no label on it indicating CTL class. There is a busbar diagram depicting full size breakers only. I have seen these diagrams also depicting minis on the bottom few stabs. The question this brings up is, if there is no CTL rating, are minis allowed and how many?

Redsy:

My take would be "NO" because the instructions you describe are specific and 110-3(b) can be cited here.

Joe & everyone,

Thanks & Happy New Year

Sorry Rojosy.
I crapped out big time on this one.
Happy New Year...S

electure,
No need to be sorry here. I appreciate all the input I get.

This might be too little, too late, but I perused my 1999 UL Electrical Construction Equipment Directory and found a statement that might pertain to your query. On page 27 it states that: "Some breakers are not provided with a means to prevent their installation in Class CTL assemblies. These circuit breakers are for use in old style, non-Class CTL equipment and are marked 'For Replacement Use Only, not CTL Assemblies.'"
So, it might be ok to have the mini breakers if they are so marked. But,if the wafer breakers are modified in order to fit the panel bus bars, then they were illegal from the get-go and you are not permitted to add more breakers to the non-code compliant panel.
Instead of a 200 A service change, it might be feasible to do a panel change to allow more breakers..

Elzappr,
I noticed the breakers you mentioned at the local sell-all supply house. In this case, the issue at hand would still be that installing these minis would allow more than 42 OC devices in this panel.
Interestiingly enough, I found another one last night. A 40 space ITE panel that had about 12 minis installed. Total count= 46 OC devices. These "cheater" breakers do not have the rejection feature that most minis have.

this might sound a tad lame, but if it's a 40 cir panel, shouldn't it automatically be a CTL ?

sparky,
One would think so. But with these minis that are notched deep enough to fit into almost any panel, one could conceivably end up with 80 OCPDs. Even on a panel that doesn't have a clear "CTL" rating, we should be bound by the NEC limitation of a maximum of 42 OCPDs. But how is Joe-handyman to know this!?

The Class CTL rating allows the use of listed "twin" or "half-size" breakers.

If there is no Class CTL label in the panel than only full size breakers may be used. It is always up to the installer (and AHJ) to install equipment as it is intended (listed).

Cheater breakers (breakers that do not contain a rejection feature) are for replacement use in only old non-Class CTL panels (of course the old panel had to be listed for these breakers).

JBD,

The upper limit should still be 42 breakers, correct? I assume a mini counts as 2 OCPDs. You could conceivably install 30 minis in a 30 ckt. panel and have 60 OCPDs. This would be a violation of 408.15.

[This message has been edited by Redsy (edited 01-09-2002).]

It would not be possible if you are using Class CTL breakers. A Class CTL panel is designed within the 42 circuit limitation.

Non-Class CTL breakers should not to be used. If you cheat and put them into non-approved panels then you are misapplying them. The installer accepts all risk associated with the misapplication of electrical equipment.