CEM - Cast-Resin LV Terminal Bushings

The insulation division of CEM manufactures and supplies a wide range of cast-resin products to meet the needs of the electrical power industry. CEM offers a complete range of LV terminal bushings to meet the requirements of distribution transformers and prides itself on the quality and service it offers – an all-important feature of the modern business climate.

By using well-established resin technology, having an excellent relationship with a reputable UK copper supplier, performing all stages of manufacturing in-house, possessing a trained and skilled workforce, and having access to one of the most experienced cast-resin technologists available in the UK today, we ensure our products are of excellent quality.

Terminal end bushings, stand-off insulators and circuit breaker/housing mouldings

We work for many blue-chip companies both in the UK and abroad. Our products include terminal end bushings for distribution transformers, and stand-off insulators and circuit breaker/housing mouldings for indoor and outdoor distribution up to 36kV.

Polyurethane cast-resin and epoxy cast-resin switchgear

At CEM we utilise the latest technology in computerised metering and dispensing equipment to maintain correct mix ratios in a wide range of products for indoor distribution switchgear up to 36kV. All casting is also controlled by state-of-the-art temperature controllers.

Polyurethane cast-resin power-distribution equipment

We provide a two-component polyurethane casting system designed for the manufacture of power distribution equipment such as switchgear components and power transmission.

Liquid-epoxy cast-resin for insulators, bushings, switchgear and transformers

At CEM we utilise a two-part electrical casting system that is suitable for insulators, bushings, switchgear and transformers. It has excellent mechanical and electrical properties.

Solid-epoxy cast-resin

CEM recognises that there are many modern epoxy resins which are in the liquid state prior to processing. These offer the advantage of minimum wastage and rapid processing times, but they do not suit every application.

Although CEM uses liquid resins for certain insulators, in some applications we consider it technically desirable to continue to use an epoxy resin that is a solid at room temperature prior to processing. This system has a proven track-record stretching over 50 years in electromechanical applications, and fully meets the requirements of BS3816 when used for indoor applications.

Monoblock bushing conductors

Bushing conductors for the four-pole combined bushing assemblies are made from 63mm x 12mm high conductivity copper bars with fully radiused edges, with the whole of the outer ends electro-tinned in accordance with class Sn 2C of BS 1872.

Both ends of any conductor are clean and free from resin for the whole of their length, from 3mm clear of the moulding. Our monoblock bushing conductors are available in 1,700A, 2,500A, 3,150A and 4,000A versions.

Monoblock bushing plates

We also offer monoblock bushing plates in 250A and 400A versions.

Four-way CT block

The four-way CT block is manufactured from epoxy resin with four brass inserts with M6 thread on each end, and two chamfered holes to allow it to be bolted down to the tank. It uses the amount of nuts and washers that will suit the number of CT terminals being used.

Nuts can be tightened to 2lb/ft of torque using a calibrated torque wrench.

Custom-made monoblocks

Using the latest engineering, we can manufacture to a customer's individual design requirements. We are happy to provide a competitive quotation from customers' drawings.

Electrical test facility for cast-resin LV terminal bushings

Our electrical test facility includes partial discharge measurement and can withstand an AC power frequency of 80kV rms.

Electrical equipment acquisition and analysis system

We utilise the latest Mtronix discharge instrument MPD540 universal current measuring system. This is a high-precision modular acquisition and analysis system for gauging current and key characteristics of electrical equipment including:

• Dissipation factor and capacitance
• Complete electrical insulation between acquisitions units

The control station provides superior safety in high-voltage setups. High-resolution digital processing enables exceptional measurement precision.