6

System

pro M compact ®

Miniature circuit-breakers

The offer at a glance

Description

The MCBs of the S 200/S 200 M series have a cur-

rent-limiting effect. They have two different trip releases

acting on the contact mechanism

1. the delayed thermal release providing overload

protection

2. the electromagnetic instantaneous release with

“hammer trip” solenoid providing fault current

protection.

They offer:

b high short-circuit capacity

b high selectivity for back-up fuse

b In case of short-circuit, low stress

on the cable in the point of fault due

to the high limitation of the let-through

ƒi2dt (current heating value).

Task

To protect against excessive temperature rises of

electric items in the case of overcurrents caused by

overload, short circuit of earth-fault current if assi-

gned according to DIN VDE 0100 Part 430. Protec-

tion against electric shock in the case of excessive

touch voltage caused by insulation fault if assigned

according to DIN VDE 0100 Part 410.

Trip charcteristics

B

C

IK ·

2 = peak value of prospective short circuit current

iD

= max. let-through current of device S 200/S 200 M

Un

= system voltage

UB

= arc voltage of MCB

tK

= breaking time of MCB

Oscillogram of rupturing process

Trip charcteristics and rated current

Independent of the type of characteristic, national codes of practice provide what highest rated current

and/or performance characteristic can be assigned to the conductor cross section to be protected (e.g.

DIN VDE 0100 Part 430).

The following assignment rules apply: Ib

In

Iz; I2

1,45 · Iz

Ib = operating current of the circuit to be expected

In = rated current of the MCB of characteristics type B, C, D, K and Z

Iz = permissible current loading of lines

I2 = conventional tripping current

B-, C- and D-type trip characteristics for line protection

Tripping behaviour according to DIN VDE 0641 Part 11.

Rated current 6 ... 63 A, (C 0,5 ... 63 A). The introduction of these trip characteristics enables direct

assignments of MCBs to the permissible load of lines I z according to DIN VDE 0298 Part 4/11.98, as the

second condition is already fulfilled (I2 = 1.45 · In).

K-type trip characteristics

Tripping behaviour according to DIN VDE 0660 Part 101 and IEC 947-2, rated current 0.5 ... 63 A,

for circuits where current-consuming appartus cause functional current peaks and for the overcurrent

protection of lines.

Z-type trip characteristics

Tripping behaviour according to DIN VDE 0660 Part 101 and IEC 947-2

Rated current 0.5 ... 63 A in 17 grades. For the protection of semiconductors and measuring circuits with

transformers.

K

Z