Conversation today is as follows;contractor#1staes that the main breaker on, say, a 200amp residential service is functionally only a "molded case switch"-designed to disconnect power to buss bars & that it does not serve,is not designed for and is incapable of functioning as a short-circuit/overload device. I dissagree!What do my Holt brethren have to say?
molded case switch vs.breaker
- Thread starter pridelion
- Start date
- Status
- Location
- Massachusetts
Re: molded case switch vs.breaker
It is a molded case circuit breaker, it is most definitely an overcurrent device or you would have a violation of 408.16 Overcurrent Protection.
It is a molded case circuit breaker, it is most definitely an overcurrent device or you would have a violation of 408.16 Overcurrent Protection.
- Location
- Massachusetts
Re: molded case switch vs.breaker
Here is some info from the UL white book
Here is some info from the UL white book
ron
Senior Member
- Location
- New York, 40.7514,-73.9925
Re: molded case switch vs.breaker
It surely is both protection for overloads and short circuits (thermal magnetic).
BTW, a molded case switch almost always has short circuit (instantaneous or magnetic)protection even though it is advertised as a switch only.
It surely is both protection for overloads and short circuits (thermal magnetic).
BTW, a molded case switch almost always has short circuit (instantaneous or magnetic)protection even though it is advertised as a switch only.
mdshunk
Senior Member
- Location
- Right here.
Re: molded case switch vs.breaker
[ October 22, 2005, 08:54 PM: Message edited by: mdshunk ]
[ October 22, 2005, 08:54 PM: Message edited by: mdshunk ]
mdshunk
Senior Member
- Location
- Right here.
Re: molded case switch vs.breaker
Is this contractor also saying that he's never found one in the tripped position? I think not. What then tripped it if it does not provide any overcurrent or short circuit protection? Statements like his would make me want to sacrifice a new breaker by smashing it open and having him look at the features inside first hand.
LarryFine
Master Electrician Electric Contractor Richmond VA
- Location
- Henrico County, VA
- Occupation
- Electrical Contractor
Re: molded case switch vs.breaker
It is and it does.
pierre
Senior Member
- Location
- Westchester County, New York
Re: molded case switch vs.breaker
Details, details, details...
A couple of things:
1. 230.90 requires overcurrent protection for ungrounded conductors at the service.
2. 230.91 Requires it to be an integral part of the service disconnecting means or immediately adjacent.
3. Service panel enclosures and the panelboard itself, if part of the "panel" assembly will be labeled with the listing of the equipment and most likely the breaker/overcurrent device.
So take a look at the label and see what it says. If the panel is rated as suitable for service equipment, you can bet the house the circuit breaker/disconnect for that enclosure is also an overcurrent device.
Details, details, details...
A couple of things:
1. 230.90 requires overcurrent protection for ungrounded conductors at the service.
2. 230.91 Requires it to be an integral part of the service disconnecting means or immediately adjacent.
3. Service panel enclosures and the panelboard itself, if part of the "panel" assembly will be labeled with the listing of the equipment and most likely the breaker/overcurrent device.
So take a look at the label and see what it says. If the panel is rated as suitable for service equipment, you can bet the house the circuit breaker/disconnect for that enclosure is also an overcurrent device.
- Status