North American classification for control switches


Classification	Designation At maximum rated voltage of			Thermal uninterrupted current	Switching capacity
AC	600 V	300 V	150 V	A	Rated voltage V	Make A	Break A	Make VA	Break VA
Heavy Duty	A600 A600 A600 A600	A300 A300 – –	A150 – – –	10 10 10 10	120 240 480 600	60 30 15 12	6 3 1.5 1.2	7200 7200 7200 7200	720 720 720 720
Standard Duty	B600 B600 B600 B600	B300 B300 – –	B150 – – –	5 5 5 5	120 240 480 600	30 15 7.5 6	3 1.5 0.75 0.6	3600 3600 3600 3600	360 360 360 360
	C600 C600 C600 C600	C300 C300 – –	C150 – – –	2.5 2.5 2.5 2.5	120 240 480 600	15 7.5 3.75 3	1.5 0.75 0.375 0.3	1800 1800 1800 1800	180 180 180 180
	– –	D300 D300	D150 –	1 1	120 240	3.6 1.8	0.6 0.3	432 432	72 72
DC
Heavy Duty	N600 N600 N600	N300 N300 –	N150 – –	10 10 10	125 250 301 to 600	2.2 1.1 0.4	2.2 1.1 0.4	275 275 275	275 275 275
Standard Duty	P600 P600 P600	P300 P300 –	P150 – –	5 5 5	125 250 301 to 600	1.1 0.55 0.2	1.1 0.55 0.2	138 138 138	138 138 138
	Q600 Q600 Q600	Q300 Q300 –	Q150 – –	2.5 2.5 2.5	125 250 301 to 600	0.55 0.27 0.10	0.55 0.27 0.10	69 69 69	69 69 69
	– – –	R300 R300 –	R150 – –	1.0 1.0 –	125 250 301 to 600	0.22 0.11 –	0.22 0.11 –	28 28 –	28 28 –
to UL 508, CSA C 22.2-14 and NEMA ICS 5