Gulf Construction Online - MCCB offers compact size, more space

Mechanical & Electrical Services

The compact MCCB range from MEM.

MCCB offers compact size, more space

The new range MCCBs introduced by the UK-based MEM is said to offer more space for wiring while incorporating a design that allows accessories to be installed safely.

01 February 2000

A NEW range of moulded-case circuit-breakers (MCCB) with ratings from 16A to 125A and an associated range of MCCB panelboards have been introduced by MEM, the UK-based manufacturer of electrical installation equipment.

Features of the new Memshield 2 G-frame MCCBs include a compact size, offering more space for wiring, and a design that allows accessories such as auxiliary contacts, alarm contacts, shunt trips or undervoltage releases to be installed simply and safely, without losing vital components, says a company spokesman.

The MCCBs are available in a choice of 'Standard', 'Hi-Break' or 'Hi-Break Adjustable' options. Although smaller than the E-frame units, which they replace, they offer a 16kA fault rating (Icu) at 400/440V ac as standard. Hi-break units have a 25 kA fault rating (Icu) at 400/440V ac and are available with fixed or adjustable thermal settings, he says.

"All units are suitable for mounting on 35 mm DIN rail or conventional mounting, without modification. They are available in single-pole, double-pole, triple-pole and four-pole (TPSN) configurations, manufactured to the international standard IEC 947-2 (BS EN 60947-2).

"The MCCBs are suitable for use in areas with high humidity and can be calibrated at 50 deg C if required (normally 40 deg C)," continues the spokesman.

A special secondary cover allows the front-fitting accessories to be slipped into position safely and easily. The secondary cover retains all the MCCB components so that there is no danger of components falling out when accessories are being fitted in situations where access is difficult. It also offers IP 2X (finger proof) protection against accidental contact, says the spokesman.

The company also provides a wide range of external accessories including inter-pole barriers to reduce the risk of creepage. Alternatively, terminal shrouds with integral barriers are available for incoming or outgoing terminals, he says.

"A rotary drive attachment allows use of panel-mounted MCCBs with an interlocked extension shaft so that cubicle doors can be opened with the switch 'off' mode.

"Clamp-type terminals will accept conductors up to 70 sq mm but spreader links are available to extend the terminals to take larger conductors or cable lugs. There are also optional rear connection studs which allow cables to be connected directly into the back of the MCCB where cubicle switchboards have rear access."

An adaptor plate is available so that the new G-frame MCCBs can be installed on panelboards designed for E-frame breakers. This feature ensures that unused ways in existing panelboards can be equipped with the new MCCB, he says.

All units provide positive contact indication with 'on', 'off', and centre 'tripped' positions. Three and four pole units have a trip-to-test button, says the spokesman.

"The new MEM G-frame MCCBs are manufactured from a high-performance engineering polymer with high-quality silver alloy main contacts for durability.

"Service and support is offered through MEM/Delta offices worldwide," he says.

MEM is a leading British manufacturer of electrical distribution equipment, established in 1908. It is a member of the international engineering group Delta and has manufacturing sites in nine countries.

The Delta Circuit Protection and Control Division has local offices in Jeddah, Saudi Arabia, and Dubai, the UAE.

The company offers a total capability in installation equipment manufacture, from medium voltage switchboards to switches socket-outlets and can provide a wide range of design and project management services for major projects, says the spokesman.