I would say that it depends on what your EVSE manual says. I googled the manual for the Clipper Creek LCS-25, and it calls for a 25 amp breaker.aFriend said:Is it OK to hookup a 25A (20A continuous) EVSE to a wire that is 8/2 (L1, L2, ground) and 40A circuit breaker instead of using 10/2 wire with 30A circuit breaker? This way, I can potentially replace EVSE in future to a 30A one in future?
Yes. As long as the continuous load is not >32 Amps, you"re OK. The purpose of a breaker or a fuse is to protect the wire, not the device.aFriend said:Is it OK to hookup a 25A (20A continuous) EVSE to a wire that is 8/2 (L1, L2, ground) and 40A circuit breaker instead of using 10/2 wire with 30A circuit breaker? This way, I can potentially replace EVSE in future to a 30A one in future?
No, use the heavy gauge wire, but use a 25A breaker.aFriend said:Is it OK to hookup a 25A (20A continuous) EVSE to a wire that is 8/2 (L1, L2, ground) and 40A circuit breaker instead of using 10/2 wire with 30A circuit breaker? This way, I can potentially replace EVSE in future to a 30A one in future?
That 1AMP lamp can't be connected on a larger circuit than what it's being rated. That's the point of having standard plugs for appliances to make sure that the circuit behind the receptacle is designed to only allow a maximum amount of current before the breaker trips. To be certified, an appliance with NEMA 5-15 plug has to have wiring able to hold 20A because that's the max current it can get on a receptacle of this type (up to 5-20). If it's too expensive to build a 1 AMP lamp with lots of 20A wire, then the appliance can have its own breaker (fuse) to protect that smaller wire.NoMoShocks said:In the example given of a 1 amp floor lamp, the test lab probably would use a 20 Amp circuit breaker for all products up to 16 Amps when conducting a limited short circuit test. The 20 amp breaker would limit the length of time the short circuit would be available to set the lamp on fire. The same short circuit in the lamp that would not cause a fire with a 20 amp circuit breaker might cause a fire with a larger circuit breaker.
Well, yes, 50 Amp if THHN wire in conduit, but not if a Romex type cable. There is a difference. Check your local code.ericsf said:40AMP breaker with 8 AWG wire is fine. This wire size is rated for 50A ...............
ericsf said:That 1AMP lamp can't be connected on a larger circuit than what it's being rated. That's the point of having standard plugs for appliances to make sure that the circuit behind the receptacle is designed to only allow a maximum amount of current before the breaker trips. To be certified, an appliance with NEMA 5-15 plug has to have wiring able to hold 20A because that's the max current it can get on a receptacle of this type (up to 5-20). If it's too expensive to build a 1 AMP lamp with lots of 20A wire, then the appliance can have its own breaker (fuse) to protect that smaller wire.NoMoShocks said:In the example given of a 1 amp floor lamp, the test lab probably would use a 20 Amp circuit breaker for all products up to 16 Amps when conducting a limited short circuit test. The 20 amp breaker would limit the length of time the short circuit would be available to set the lamp on fire. The same short circuit in the lamp that would not cause a fire with a 20 amp circuit breaker might cause a fire with a larger circuit breaker.
If the lamp shorts, the #18 wire used in the lamp should survive long enough to trip the 20A breaker. The caveat is a sustained fault, such as arcing, that will keep the threshold below the trip curve of the 20A breaker, but still set fire to the wire. This is rare but possible, and this is why the AFCI (Arc Fault Circuit Interrupter) was introduced.QueenBee said:ericsf, are you really trying to say that the #16 and #18 wire used in lamps, small appliances, etc. is rated for 20 amps?
NoMoShocks, could you provide a time current curve of a breaker that shows that during a short circuit event a 15 amp breaker takes longer than a 20 amp breaker? I think you might be confusing the two methods of action in a circuit breaker. I don't know how many amps a short circuit event is but considering a residential breaker is designed to be able to interrupt 10,000 amps I suspect any short circuit event is going to utilize the instantaneous tripping mechanism and not the time delay thermal trip mechanism. During a short circuit in the lamp there is no saving the lamp wiring but the circuit breaker can save the house wiring.
No. What I was trying to say was that its not the panel breaker that protects such appliance but an internal fuse which rating must protect the weakest wire in the appliance. If you can build an appliance with all its wire 20amp rated in this case you don't need to protect it with its own fuse. Going either way is usually a design (wire vs fuse cost) decision.QueenBee said:ericsf, are you really trying to say that the #16 and #18 wire used in lamps, small appliances, etc. is rated for 20 amps?
IMHO you're wasting money on a 25a breaker. But as long as the wire you put in the wall can support 40amp, it's safe.davewill said:Here's my take. Changing the circuit breaker is fairly easy, and I feel confident doing it on a DIY basis. So I would change it out to 25a, and plan on putting the 40a breaker back if and when I upgraded EVSEs.
ericsf said:No. What I was trying to say was that its not the panel breaker that protects such appliance but an internal fuse which rating must protect the weakest wire in the appliance. If you can build an appliance with all its wire 20amp rated in this case you don't need to protect it with its own fuse. Going either way is usually a design (wire vs fuse cost) decision.QueenBee said:ericsf, are you really trying to say that the #16 and #18 wire used in lamps, small appliances, etc. is rated for 20 amps?
Yea. You could plug this in a 20 amp receptacle and power 3 appliances each drawing 4-5 amp. 15 amp continuous is what the 20amp breaker will allow. The cord is rated for 13amp. It will get warm but probably won't set a fire. But at this point I don't know really how this can be fool proof safe. I guess that's why we still have electrical fires.QueenBee said:ericsf said:No. What I was trying to say was that its not the panel breaker that protects such appliance but an internal fuse which rating must protect the weakest wire in the appliance. If you can build an appliance with all its wire 20amp rated in this case you don't need to protect it with its own fuse. Going either way is usually a design (wire vs fuse cost) decision.QueenBee said:ericsf, are you really trying to say that the #16 and #18 wire used in lamps, small appliances, etc. is rated for 20 amps?
I admit I haven't dissected molded plugs so I am just assuming there are not hidden fuses in #16 and #18 lampcord type cords, are you saying there are? My point is just that there is nothing protecting for example this extension cord from being overloaded and melting: http://www.homedepot.com/p/Nonbrand-6-ft-16-2-Cube-Tap-Extension-Cord-HD-145-017/100672781#.Uc25kvnCZsI" onclick="window.open(this.href);return false;
ericsf said:Yea. You could plug this in a 20 amp receptacle and power 3 appliances each drawing 4-5 amp. 15 amp continuous is what the 20amp breaker will allow. The cord is rated for 13amp. It will get warm but probably won't set a fire. But at this point I don't know really how this can be fool proof safe. I guess that's why we still have electrical fires.ericsf said:QueenBee said:ericsf, are you really trying to say that the #16 and #18 wire used in lamps, small appliances, etc. is rated for 20 amps?
I admit I haven't dissected molded plugs so I am just assuming there are not hidden fuses in #16 and #18 lampcord type cords, are you saying there are? My point is just that there is nothing protecting for example this extension cord from being overloaded and melting: http://www.homedepot.com/p/Nonbrand-6-ft-16-2-Cube-Tap-Extension-Cord-HD-145-017/100672781#.Uc25kvnCZsI" onclick="window.open(this.href);return false;
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