The label inside that service disconnect can says “suitable for use as service equipment when used with hold down kit…”.Jason, A separate building always requires a grounding electrode system in addition to the equipment grounding conductor that you mention. When you buy a Square D 100 amp weatherproof outdoor service disconnect can, for instance, you use a regular QO breaker in it with a hold down. There are no UL listed breakers that are alone marked as being suitable for use as a service disconnect. The UL White Book has about 6 pages near the end dedicated to the qualifications of a panelboard to be marked as suitable for use as a service disconnect. The UL only listed panelboards as being suitable for use as service equipment, and not breakers. The Square D catalog table note lists any of their thermal-magnetic breakers as acceptable for use as service disconnecting means when used with hold down kit part number blah, blah, blah. For instance, CH 100 amp panels use a regular back fed 100 amp breaker, right from the factory. The service rated “disconnect” will usually be twice as big as the branch breaker for a given amp rating. You should see a breaker “suitable as service equipment” (or words to that effect) and not a regular branch circuit/feeder breaker. You will notice the only real difference in backfeeding is when this is the service disconnect. I guess another would be to reduce the “EASE” of someone removing a 100A and replaceing it with a 125A…BUT we know a screwdriver wont stop them from trying…but it is yet another reason…Īlso since it is being used as the main OCPD of the enclosure it should to be fixed…so the retention clip helps handle that…and I am sure others will have many other reasons…and some will say because it is code…in the end all valid points. There are many reasons for this…but I personally experience one reason alot…the conductors are generally larger like # 2 AWG and so on with these and the breakers snap in but don’t hold real tight sometimes and can pop out or pull loose, they can pull loose enough to offer a poor connection as well which could result in some impedance or resistance ( depending on how you want to look at…you DC Guys out there… and well…thats one reason…reduce the likelyhood is one. Supply conductors shall be secured in place by an additionalįastener that requires other than a pull to release theĭevice from the mounting means on the panel. SO…panel is probably rated for 200A, Meter outside is probably rated for 200A, BREAKER being used is rated for 100A and the conductors feeding the panel are rated for 100A…it is a 100A service.ĭevices or plug-in type-main lug assemblies that areīackfed and used to terminate field-installed ungrounded Now on that backfed breaker…make sure it is supported in the box by something OTHER than the standard snap in of the device…it has to be retained by a clip or similar device.Īlso…ignore the 200CL on the meter…does not play a role here. # 2 CU can handle 125A respectfully )…but in this case because it is # 2 it can no way handle or be a 200A service and this is probably why they did not use the 200A main breaker in this enclosure.Ĭheck out my video on sizing a service - and it will help you I am sure. You have to size based on the weakest link concept, if the conductors coming in are 2 AWG AL or ( even 2 AWG CU ) then based on 310.15(b)(6) of the NEC it can handle 100A…(P.S. Your question is how can you tell if this service can be 200A…that depends on the factors involved. It appears they are back feeding this panel for use as a 100A panel.
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