Philips Electromagnetic Lamp manual According to CEE-19-2nd edition L, U and K, 3.18

5 3.18 Circuit breakers, fusing and earth leakage

The same applies to main circuit breakers (MCB’s).Although the switching characteristics of MCB types are laid down in recommendations like CEE-19-2ndedition, the various characteristics of different types and brands can differ considerably.

Circuit breakers are tested and calibrated to carry 100 per cent of their rated current in open air at a specified temperature, normally 25 ºC. When mounted in an enclosure, the ambient temperature may be higher.As a result, circuit breakers are permitted continuously to carry only 80 per cent of their current rating.The manufacturer’s technical information should be carefully reviewed to determine the exact capabilities of a specific breaker.

Main circuit breakers work on two principles:

1)The thermal part, being a bi-metal strip, which is heated by the passing current.The switching-off characteristic is similar to that of a fuse and is influenced by time and current value. It is effective after approx. minimum 2 to 5 seconds for the smaller overload currents.

2)The electromagnetic part, being a magnet coil, which is effective for the high overload currents and reacts within milliseconds (see Fig. 140).

switching time (s) switching time (s)

Fig. 140. Switching characteristics of various types of main circuit breakers.

10000
1000
100
10
1
											L-	curve
.1											U-	curve
0
											K-	curve
.01
0
.001
0
	.5	1	2	3	5	7	10	20	30	50	70	100	200 300
	0

multiple of nominal current

10000 1000 100

10

1

.1 0

.01 0

				B			C		D
1	.5	2	3	4	5	6	8	10	15	20	30
	1

multiple of nominal current

According to CEE-19-2ndedition (L, U and K) According to EN 60898 / VDE 0641 (B, C and D)

For lighting applications the less sensitive types of circuit breakers are advised, such as the U-, K-, C- or D types.

Taking the 10 A MCB type C as a reference (with a load assumed to be 1), then the other types can handle loads as shown in the following table:

C-type		B-type		L-type		U-type		K-type
10 A	16 A	10 A	16 A	10 A	16 A	10 A	16 A	10 A	16 A
1	1.6	0.6	1	0.7	1.1	1.3	2.1	1.5	2.5

146