a) MCCBs  have a range of short circuit capacities from 25kA to 150kA; selection will be

determined by the prospective short circuit at the point of installation.

b) MCCBs will be available as 3 pole or 4 pole devices throughout the current range.

c) MCCBs will be suitable for the protection of a variety of common load types. As a minimum

requirement this must include: -

· System protection

· Cable protection

· Generator protection

· Motor protection

d) Where an MCCB is selected for the protection of an individual motor then the device must

provide single phasing sensitivity in accordance with IEC/EN60947-4 or a separate motor

overload device must be fitted to provide this.

e) MCCBs will be able to operate in ambient temperatures up to and including 50 degrees

centigrade without any de-rating of the device or modification of the trip setting.

f) MCCBs must be suitable to operate with voltages up to 690V AC 50/60Hz.

g) Thermal & Magnetic releases must be independently adjustable from the front of the device.

h) When a motor drive (remote operating) mechanism is fitted the system must allow for local,

manual activation (opening & closing) of the device, with or without the motor drive being

electrically connected.

i) MCCBs must have the option of electronic sensing systems for ratings of 100A and above

(with a minimum thermal setting of 50A)

j) When an electronic sensing system is selected, local indication of the pre-set “load

threshold� must be provided on the front of the MCCB by means of an LED.