100 Amp Panel Breaker Capacity
- Thread starter pgrwd
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Re: 100 Amp Panel Breaker Capacity
The old style Tandem Breakers may be used in the panels that do not prevent the installation of more circuit breaker poles than the number for which the assembly is designed and rated for. These are old style, Non-Class CTL equipment and are marked ?For Replacement use only, not CTL Assemblies.? They are made to replace tandems that were manufactured before the CTL requirement built into the panels by UL. They can be used only to Service the Old Style Non-Class CTL QO Panels. When they are installed in the new CL panel it is a violation of its UL listing and the National Electrical Code.
? UL White Book Circuit Breakers (DHJR)
? UL White Book Panelboards (QEUY)
? NEC 110.3(A)(7) Examination, Identification, Installation and Use of Equipment
? NEC 408.15 Number of Overcurrent Devices on One Panelboard.
?..more overcurrent devices than that number for which the panel board was designed rated, and approved.
The old style Tandem Breakers may be used in the panels that do not prevent the installation of more circuit breaker poles than the number for which the assembly is designed and rated for. These are old style, Non-Class CTL equipment and are marked ?For Replacement use only, not CTL Assemblies.? They are made to replace tandems that were manufactured before the CTL requirement built into the panels by UL. They can be used only to Service the Old Style Non-Class CTL QO Panels. When they are installed in the new CL panel it is a violation of its UL listing and the National Electrical Code.
? UL White Book Circuit Breakers (DHJR)
? UL White Book Panelboards (QEUY)
? NEC 110.3(A)(7) Examination, Identification, Installation and Use of Equipment
? NEC 408.15 Number of Overcurrent Devices on One Panelboard.
?..more overcurrent devices than that number for which the panel board was designed rated, and approved.
bill addiss
Senior Member
Re: 100 Amp Panel Breaker Capacity
No argument there. I think goldstar just wanted to caution about giving anybody any ideas they didn't already know about. There's really no way to know who may be reading stuff here and many people don't care if it's a violation or not as long as it works.
Bill
a.wayne,
No argument there. I think goldstar just wanted to caution about giving anybody any ideas they didn't already know about. There's really no way to know who may be reading stuff here and many people don't care if it's a violation or not as long as it works.
Bill
pierre
Senior Member
- Location
- Westchester County, New York
Re: 100 Amp Panel Breaker Capacity
There is no magic or special formulas... it is simple math.
100 amps X 240 volts = 24,000 VA. That is your load permitted.
How many circuits permitted is a little different and requires reading skills. Every panel board manufacturer is required to label the panel. One of the panel label requirements is the number of circuits permitted by the manufacturer on that panelboard. The label is usually affixed to the inside of the enclosure. Some manufacturers provide a sheet or small booklet with the panel that also has the same information.
Pierre
There is no magic or special formulas... it is simple math.
100 amps X 240 volts = 24,000 VA. That is your load permitted.
How many circuits permitted is a little different and requires reading skills. Every panel board manufacturer is required to label the panel. One of the panel label requirements is the number of circuits permitted by the manufacturer on that panelboard. The label is usually affixed to the inside of the enclosure. Some manufacturers provide a sheet or small booklet with the panel that also has the same information.
Pierre
hurk27
Senior Member
- Location
- Portage, Indiana NEC: 2008
Re: 100 Amp Panel Breaker Capacity
I believe this Inspector is getting mixed up with the requirement of a main lug power panel being used from a meter without any main disconnect before it, as then the panel is limited to 6 double pole breakers hence 12 breaker spaces.
This is not the same as the requirments for a main lighting and branch circuit panel.
I believe this Inspector is getting mixed up with the requirement of a main lug power panel being used from a meter without any main disconnect before it, as then the panel is limited to 6 double pole breakers hence 12 breaker spaces.
This is not the same as the requirments for a main lighting and branch circuit panel.
goldstar
Senior Member
- Location
- New Jersey
- Occupation
- Electrical Contractor
Re: 100 Amp Panel Breaker Capacity
Awayne,
Bill Addiss said it in exactly the right way. I did not mean anything derogatory when I suggesting that you not post ideas on how to bypass mechanical devices to prevent illegal installations of breakers. While we would all like to believe we're ALL professionals sharing ideas here in this forum and our moderators are doing a great job of screening new subscribers and posts, the fact remains that there may, in fact, be just plain homeowners here taking information like an illegal breaker modification and putting it to ill use. My point was "why give them any ideas".
As I'm sure you know, non-electrician homeowners can become dangerous with just a little wrong information. I recently went to meet a homeowner who was going to add central air to her home but needed a service upgrade. When I inspected her 100 amp MB panel it was filled to capacity and had several tandem breakers in it. I began to explain the costs and what was involved in bumping her up to 150 or 200 amps. She then said that someone in her office mentioned that if you plugged in a 2-pole 50 amp breaker into her existing panel and hung a sub-panel next to it she would then have a 150 amp service. Now, I know I'm not the most eloquent speaker in the world but, I can usually hold my own in most situations. I found myself at a loss for words having to defend myself and my trade against something she took as gospel from a neophyte in her office. Needless to say, I didn't get the job. I'm sure she'll hunt around until she finds someone who will do just that, take her for a few $$$, "slam their trunk" and drive away with a "tail light" warranty !!
[ May 16, 2004, 01:28 PM: Message edited by: goldstar ]
Awayne,
Bill Addiss said it in exactly the right way. I did not mean anything derogatory when I suggesting that you not post ideas on how to bypass mechanical devices to prevent illegal installations of breakers. While we would all like to believe we're ALL professionals sharing ideas here in this forum and our moderators are doing a great job of screening new subscribers and posts, the fact remains that there may, in fact, be just plain homeowners here taking information like an illegal breaker modification and putting it to ill use. My point was "why give them any ideas".
As I'm sure you know, non-electrician homeowners can become dangerous with just a little wrong information. I recently went to meet a homeowner who was going to add central air to her home but needed a service upgrade. When I inspected her 100 amp MB panel it was filled to capacity and had several tandem breakers in it. I began to explain the costs and what was involved in bumping her up to 150 or 200 amps. She then said that someone in her office mentioned that if you plugged in a 2-pole 50 amp breaker into her existing panel and hung a sub-panel next to it she would then have a 150 amp service. Now, I know I'm not the most eloquent speaker in the world but, I can usually hold my own in most situations. I found myself at a loss for words having to defend myself and my trade against something she took as gospel from a neophyte in her office. Needless to say, I didn't get the job. I'm sure she'll hunt around until she finds someone who will do just that, take her for a few $$$, "slam their trunk" and drive away with a "tail light" warranty !!
[ May 16, 2004, 01:28 PM: Message edited by: goldstar ]
pierre
Senior Member
- Location
- Westchester County, New York
Re: 100 Amp Panel Breaker Capacity
Phil
In regards to your last post, it never ceases to amaze me how people will listen to the 'nonexpert' as far as information, as opposed to listening to the professional. I have learned that it is not info they are looking for, but how to save money. Let them suffer in their own misery when it does not work later.
Pierre
Phil
In regards to your last post, it never ceases to amaze me how people will listen to the 'nonexpert' as far as information, as opposed to listening to the professional. I have learned that it is not info they are looking for, but how to save money. Let them suffer in their own misery when it does not work later.
Pierre
goldstar
Senior Member
- Location
- New Jersey
- Occupation
- Electrical Contractor
Re: 100 Amp Panel Breaker Capacity
Pierre,
You know the story - we charge a lot of money for what we do so we're probably trying to rip people off by gold plating the job when we explain that we have to replace the SE cable, meter pan, breaker panel and breakers, install ground rods and bond water meters and water heaters, when increasing the service to 150 amps can be as easy as installing 50 amp breaker into a 100 amp MB panel and hanging on a new sub-panel. After all, she's worked with this person a long time and trusts what they say. We're just contractors trying to take some of her hard earned money !!!
[ May 16, 2004, 01:49 PM: Message edited by: goldstar ]
Pierre,
You know the story - we charge a lot of money for what we do so we're probably trying to rip people off by gold plating the job when we explain that we have to replace the SE cable, meter pan, breaker panel and breakers, install ground rods and bond water meters and water heaters, when increasing the service to 150 amps can be as easy as installing 50 amp breaker into a 100 amp MB panel and hanging on a new sub-panel. After all, she's worked with this person a long time and trusts what they say. We're just contractors trying to take some of her hard earned money !!!
[ May 16, 2004, 01:49 PM: Message edited by: goldstar ]
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