The Guide - MEM Technical Support

Current Discrimination
Circuit Breakers

Current Discrimination - Prospective Fault Levels to which Discrimination is achieved (A)

Upstream:
BS 88 Fuse MEM SB3 to SH10.
Downstream:
Memshield 2 Type 2 Type B & C MCB to Memshield 2 K Frame MCCB.

Full discrimination to the fault level of the downstream circuit breaker applies for all MCB types and standard range MCCBs. Hi-Break MCCBs will discriminate to at least the level shown.

Upstream
Fuse Rating (A)		20	25	32	40	50	63	80	100	125	160	200	250	315	355	400	450	500	560	630	710	800
Breaker Rating (A) Memshield 2 MCB Type B&C	1	160	280	650	1600	2600	5400	7500	10000	10000	10000	10000	10000	10000	10000	10000	10000	10000	10000	10000	10000	10000
	2	160	280	650	1600	2600	5400	7500	10000	10000	10000	10000	10000	10000	10000	10000	10000	10000	10000	10000	10000	10000
	4	160	280	650	1600	2600	5400	7500	10000	10000	10000	10000	10000	10000	10000	10000	10000	10000	10000	10000	10000	10000
	6	160	280	650	1600	2600	5400	7500	10000	10000	10000	10000	10000	10000	10000	10000	10000	10000	10000	10000	10000	10000
	8	-	230	450	1000	1600	2700	3700	10000	10000	10000	10000	10000	10000	10000	10000	10000	10000	10000	10000	10000	10000
	10	-	230	450	1000	1600	2700	3700	10000	10000	10000	10000	10000	10000	10000	10000	10000	10000	10000	10000	10000	10000
	13	-	-	280	650	950	1800	2300	7000	10000	10000	10000	10000	10000	10000	10000	10000	10000	10000	10000	10000	10000
	16	-	-	280	650	950	1800	2300	7000	10000	10000	10000	10000	10000	10000	10000	10000	10000	10000	10000	10000	10000
	20	-	-	-	600	880	1750	2200	6100	10000	10000	10000	10000	10000	10000	10000	10000	10000	10000	10000	10000	10000
	25	-	-	-	-	750	1500	1800	4600	6200	10000	10000	10000	10000	10000	10000	10000	10000	10000	10000	10000	10000
	32	-	-	-	-	750	1500	1800	4600	6200	10000	10000	10000	10000	10000	10000	10000	10000	10000	10000	10000	10000
	40	-	-	-	-	-	1200	1600	4000	5500	10000	10000	10000	10000	10000	10000	10000	10000	10000	10000	10000	10000
	50	-	-	-	-	-	-	1400	3400	4500	7000	10000	10000	10000	10000	10000	10000	10000	10000	10000	10000	10000
	63	-	-	-	-	-	-	-	500	3000	7000	4250	10000	10000	10000	10000	10000	10000	10000	10000	10000	10000
Fuse Rating (A)		20	25	32	40	50	63	80	100	125	160	200	250	315	355	400	450	500	560	630	710	800
Breaker Rating (A) Memshield 2 MCCB G Frame	16	-	-	-	450	530	1600	1600	1600	1800	2300	4300	8000	14000	16000	16000	16000	16000	16000	16000	16000	16000
	20	-	-	-	-	550	1000	1000	1600	1800	2300	4300	8000	14000	16000	16000	16000	16000	16000	16000	16000	16000
	32	-	-	-	-	-	-	920	1600	1750	2200	4000	6000	8500	13250	16000	16000	16000	16000	16000	16000	16000
	40	-	-	-	-	-	-	-	1600	1750	2200	3700	5250	7500	11000	16000	16000	16000	16000	16000	16000	16000
	50	-	-	-	-	-	-	-	-	1700	2100	3500	4900	6700	9600	16000	16000	16000	16000	16000	16000	16000
	63	-	-	-	-	-	-	-	-	1700	2100	3500	4900	6700	9600	16000	16000	16000	16000	16000	16000	16000
	80	-	-	-	-	-	-	-	-	-	-	3250	4500	6000	8500	16000	16000	16000	16000	16000	16000	16000
	100	-	-	-	-	-	-	-	-	-	-	3250	4500	6000	8500	16000	16000	16000	16000	16000	16000	16000
	125	-	-	-	-	-	-	-	-	-	-	-	-	6000	8500	16000	16000	16000	16000	16000	16000	16000
Fuse Rating (A)		20	25	32	40	50	63	80	100	125	160	200	250	315	355	400	450	500	560	630	710	800
Breaker Rating (A) Memshield 2 MCCB F Frame	16	-	-	-	500	580	800	1000	1600	2200	2600	4800	8500	14500	25000	25000	25000	25000	25000	25000	25000	25000
	20	-	-	-	450	550	820	1000	1600	2200	2600	4800	8500	14500	25000	25000	25000	25000	25000	25000	25000	25000
	32	-	-	-	-	-	-	1000	1600	2200	2600	4700	7200	10000	14500	25000	25000	25000	25000	25000	25000	25000
	40	-	-	-	-	-	-	-	1600	2200	2600	4600	7000	9300	13000	25000	25000	25000	25000	25000	25000	25000
	50	-	-	-	-	-	-	-	-	2200	2600	4500	6800	8800	12000	23500	25000	25000	25000	25000	25000	25000
	63	-	-	-	-	-	-	-	-	-	-	4300	6800	8800	12000	23500	25000	25000	25000	25000	25000	25000
	80	-	-	-	-	-	-	-	-	-	-	4200	6000	8000	10000	22000	25000	25000	25000	25000	25000	25000
	100	-	-	-	-	-	-	-	-	-	-	-	6000	8000	10000	22000	23500	23500	25000	25000	25000	25000
	125	-	-	-	-	-	-	-	-	-	-	-	-	8000	10000	22000	23500	23500	25000	25000	25000	25000
	160	-	-	-	-	-	-	-	-	-	-	-	-	-	9500	18500	22000	22000	25000	25000	25000	25000
	200	-	-	-	-	-	-	-	-	-	-	-	-	-	-	-	-	-	25000	25000	25000	25000
Fuse Rating (A)		20	25	32	40	50	63	80	100	125	160	200	250	315	355	400	450	500	560	630	710	800
Memshield 2 MCCB J Frame	160	-	-	-	-	-	-	-	-	-	-	-	-	-	-	1800	22000	22000	32000	36000	36000	36000
	200	-	-	-	-	-	-	-	-	-	-	-	-	-	-	-	13000	13500	15000	35000	36000	36000
	250	-	-	-	-	-	-	-	-	-	-	-	-	-	-	-	-	-	9700	17000	17000	36000
Fuse Rating (A)		20	25	32	40	50	63	80	100	125	160	200	250	315	355	400	450	500	560	630	710	800
Memshield 2 MCCB K Frame	250	-	-	-	-	-	-	-	-	-	-	-	-	-	-	-	-	8100	9500	18000	18000	36000
	320	-	-	-	-	-	-	-	-