Low Voltage Switchgear

Motor starter boards, AC and DC

TCL are able to supply the switchgear, or motor control centres (MCC), for AC and DC low voltage drives. The MCC can be designed to fit into the footprint of existing panels that require replacing and will be arranged to allow the utilisation of the existing field cables.

Using the latest technology in motor switchgear the MCC systems are able to provide many functions not available with older switchgear, including:-

- Connection to a remote PLC/DCS via a serial communications link
- Remote logging of motor data for maintenance analysis, including:-

  • Motor current
  • Running hours
  • Peak currents

- Motor soft start, eliminating the need for star-delta control

TCL offer a flexible design approach so that the panels are built to match the client’s requirements, options that can be accommodated include:-
- Front panel indications and controls
- Hard-wired or serial connection to the main control system

The panels are built and assembled at our works in Leicester and the panels are subjected to a thorough test procedure which includes:-
- Insulation tests
- Full function test of each drive
- Part or full load current test with test motor

Advantages to the operator will include:-
- Reduced parasitic load by running drives at part load to match demand
- Increased monitoring facilities allowing faster fault detection
- More effective maintenance planning

DC Motor starters

Many gas turbines are used for emergency generation and so they require DC motors, for the auxiliary systems, in order to provide the ability to start without AC auxiliary supplies. The switchgear or motor starters are often powered by 120 Vdc batteries.

For the larger drives there is a requirement for current control during the starting phase, which has traditionally been accomplished using resistors and contactors. The 120 Vdc contactors required for these motor starters are now obsolete making spare parts hard to obtain.

TCL are now able to supply DC motor switchgear which includes soft-start functions based on semi-conductor technology. This technology was initially developed for the DC starters of aero-derivative gas turbines, but has now been extended to small drives, such as the lubrication oil pumps and fuel pumps. The TCL SmartStart provides a soft start for DC motors and has been successfully installed on a number of gas turbines worldwide.