M  & M ELECTRICAL SERVICES        

Carrying out “live” testing after replacing Triple Pole Incomer switch to a distribution board in one of our clients facilities located in Chester.

The original incomer unit had failed and had to be replaced with a matter of urgency.

Recent installation of low energy (compact fluorescent) recessed down-light fittings with drop-glass reflectors in a foyer area of an office block.  This area is not normally occupied so switching is controlled by passive infra-red sensors which provides maximum energy savings. Also the addition of a concealed door entry system with intercom, integrated monitors displaying company products and integrated cross air flow system.

Emergency lighting was also incorporated into the installation in accordance with Building Regulations.

The corridor lighting is also part of the installation and again the switching is controlled by passive infra-red sensors to provide maximum energy savings.

The emergency lighting has a concealed test switch in accordance with IEE Regulations to enable functional testing of the system.

Recent lighting installation which consisted of replacing 2400 mm (T 12) single lamp, switch-start fittings with 1800 mm (T 8) H/F, 865L (Daylight) twin lamp fittings with angled reflectors.  Utilizing existing wiring the light output was increased by 125% with an increase of power consumption of less than 40%.

The T 12 fitting is now classed as obsolete and is recognised as being an inefficient lighting unit compared to modern standards, in many cases the T 12 can be directly replaced by T 8 units without the need for rewiring.

A common problem incurred by customers occurs when motors controlled by AC/DC drives often run continuously at a percentage of their full speed (RPM) because of the particular application or process that is required, i.e. a 1500 rpm motor running at a constant speed of 568 rpm as shown in the photo.

The motor is designed to operate at 1500 rpm and is a totally enclosed fan ventilated motor (TEFV).

Heat build-up in the motor can be far greater when running at a reduced speed because the amount of cooling ventilation required to dissipate the heat is also reduced.

As shown in the photo a solution is to install a motor with a separately supplied fan unit which will provide a constant air flow for the motor regardless of the motor drive speed.

This can be a very effective method of reducing motor burn out problems with the obvious beneficial effects of reducing production breakdowns.