Yes, if properly wired a 20 amp circuit is a great circuit for an 18 amp appliance.
Properly wired means you've used 12 gauge wire or larger and the circuit is protected by a 20 amp breaker or fuse and all connections are secure.
You should not exceed 80% of the breaker rating for a continuous load. Therefore, the continuous load should not exceed 16 amps.
No. You need 20 amp receptacles. ( if a single receptacle on an individual brach circuit NEC 210.21 (B)(1) ) Yes you can use a 15 amp receptacles on a 20 amp breaker in the states but not in canada. ( branch circuit supplying two or more receptacle NEC 210.21(B)(3) ) 15 amp receptacle on a 20 amp circuit is not code, partly because 20 amp circuits use #10 ga wire, which does not fit unto a 15 amp receptacle,(can be forced but lots of work.) Also a 15 amp receptacle will not take the 18 amps continuios that a 20 amp recep. will. ( It is code, see above. 14 awg = 15 amp, 12 awg = 20 amp, 10 awg = 30 amp ) 20 amp wire is 12 gauge not 10 Yes you can use 15A outlets and swithes on 20 amp breakers they are UL listed for 20 amp even if they are stamped for 15A as long as the wire is 12ga to. ( NEC Table 210.21 (B)(3) )
Only if you want to blow up the microwave. That will let 20 amps go through before the fuse blows when the manufacture is telling you 18 amps max. <<>> Yes, you can use the 20 amp fuse. At 250 volts 2 amps is no problem and you are not going to blow up the microwave. On a fault current the 20 amp fuse will trip just as fast as an 18 amp fuse.
Residential power is usually 115 volts to 120 volts and will power a 15 amp air conditioner. If it is on a 15 amp breaker it may heat up the breaker and cause it to trip if it runs continuously in which case you would need to move it to a 20 amp circuit.A 20 amp circuit will handle 18 amps continuously without overheating the breaker and making it trip. A 15 amp circuit can handle 12 amps continuously without over heating the breaker.You cannot simply replace the 15 amp breaker with a 20 amp breaker because the 15 amp circuit uses smaller wire which might overheat.The term 110 is an old one. Most home power now is at least 115 volts.
In a typical US automobile, a 30 amp fuse will sustain a constant load of 360 watts. Fuses and circuit breakers perform on an "I squared t" rule. For example, a 30 amp fuse will not blow on 31 amps for a very long time. A 20 amp breaker can take anywhere from 10 minutes to two hours to trip on 25 amps. We simply dumb it down so that laymen and technicians need not make mistakes. Power on seven 100 watt light bulbs simultaneously. That means a circuit suddenly provides 50 amps. 50 amps does not trip a 15 amp or 20 amp breaker, again, due to the "I squared t" rule. A 50 amps load only exists for tens of milliseconds. Not long enough. A 30 amp continuous appliance will not trip a 30 amp breaker. But a safety margin means limiting 30 amp appliances to 26 amps or less. Meanwhile, an 18 gauge lamp cord wire typically rated for 10 amps will actually conduct up to 50 amps continuously. Again, that wire is oversized for other safety reasons. And to keep it simple. These concepts apply to fuses vehicles and structures.
You should not exceed 80% of the breaker rating for a continuous load. Therefore, the continuous load should not exceed 16 amps.
Just connect the circuit. It will only draw the amps it needs to operate. It is just like connecting a 100 watt light bulb that draws way less than 1 amp, to a 20 amp household circuit.
would discharge in 18 hours
It will draw over 18 amps and will blow a 15 amp fuse.
No. You need 20 amp receptacles. ( if a single receptacle on an individual brach circuit NEC 210.21 (B)(1) ) Yes you can use a 15 amp receptacles on a 20 amp breaker in the states but not in canada. ( branch circuit supplying two or more receptacle NEC 210.21(B)(3) ) 15 amp receptacle on a 20 amp circuit is not code, partly because 20 amp circuits use #10 ga wire, which does not fit unto a 15 amp receptacle,(can be forced but lots of work.) Also a 15 amp receptacle will not take the 18 amps continuios that a 20 amp recep. will. ( It is code, see above. 14 awg = 15 amp, 12 awg = 20 amp, 10 awg = 30 amp ) 20 amp wire is 12 gauge not 10 Yes you can use 15A outlets and swithes on 20 amp breakers they are UL listed for 20 amp even if they are stamped for 15A as long as the wire is 12ga to. ( NEC Table 210.21 (B)(3) )
18 gauge
Possibly, most 230 volt saws draw about 16-18 amps on each line. There will be a spec plate on or by the motor which has the amp draw marked. CHECK this first.
The formula you are looking for is I = E/R. Amps = Volts/Resistance. If you say it is normally a 2 Amp circuit, it normally draws 2 amps. Therefore the original resistance offered to the 12v battery is 2/12 = 6 Ohms. If you then connect a 12 Ohm resistor in series, they are added, so R = 18 Ohms. Now if you put 12v across this circuit it will draw 12/18 = 0.66 Amps. Or If you just put a 12 Ohm resistor across the 12v supply it will draw 1 Amp. If the circuit is protected by a 2 Amp fuse, it will not blow, but the resistor will get hot.
Only if you want to blow up the microwave. That will let 20 amps go through before the fuse blows when the manufacture is telling you 18 amps max. <<>> Yes, you can use the 20 amp fuse. At 250 volts 2 amps is no problem and you are not going to blow up the microwave. On a fault current the 20 amp fuse will trip just as fast as an 18 amp fuse.
Residential power is usually 115 volts to 120 volts and will power a 15 amp air conditioner. If it is on a 15 amp breaker it may heat up the breaker and cause it to trip if it runs continuously in which case you would need to move it to a 20 amp circuit.A 20 amp circuit will handle 18 amps continuously without overheating the breaker and making it trip. A 15 amp circuit can handle 12 amps continuously without over heating the breaker.You cannot simply replace the 15 amp breaker with a 20 amp breaker because the 15 amp circuit uses smaller wire which might overheat.The term 110 is an old one. Most home power now is at least 115 volts.
In a typical US automobile, a 30 amp fuse will sustain a constant load of 360 watts. Fuses and circuit breakers perform on an "I squared t" rule. For example, a 30 amp fuse will not blow on 31 amps for a very long time. A 20 amp breaker can take anywhere from 10 minutes to two hours to trip on 25 amps. We simply dumb it down so that laymen and technicians need not make mistakes. Power on seven 100 watt light bulbs simultaneously. That means a circuit suddenly provides 50 amps. 50 amps does not trip a 15 amp or 20 amp breaker, again, due to the "I squared t" rule. A 50 amps load only exists for tens of milliseconds. Not long enough. A 30 amp continuous appliance will not trip a 30 amp breaker. But a safety margin means limiting 30 amp appliances to 26 amps or less. Meanwhile, an 18 gauge lamp cord wire typically rated for 10 amps will actually conduct up to 50 amps continuously. Again, that wire is oversized for other safety reasons. And to keep it simple. These concepts apply to fuses vehicles and structures.
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