Main Switch Board(MSB) Safeties, Protection and Maintenance
Main Switch Board (MSB) Safeties
- MSB to be installed on a raised platform.
- The location where MSB is installed should have good ventilation, illumination and affected by minimum vibration.
- No water or oil pipes should pass above the MSB.
- There should be adequate space around allowing comfortable operation ans maintenance.
- The operating floor space in front and behind the MSB should be covered with anti skid, insulated rubber mats with a minimum thickness of 15 mm.
- Panel doors should be in locked position.
- Door opening mechanism should be interlocked with power supply.
- The enclosure should be drip proof.
- MSB should be dead front type. (i.e. All the live conductor should pass behind MSB)
- Every equipment onboard must be properly earthed. Also MSB must be properly earthed.
- Every incoming and outgoing feed must be protected by a switch fuse or circuit breaker.
- Insulation resistance should not be less than 1 Mega Ohm in any case. Insulation Resistance (IR) to be checked and records are maintained.
- All meters must be calibrated periodically and records are maintained.
- All the meters, switches, fuses, push button, indicating lamps, etc. should be in working condition and identified with individual name plate or tag.
- All the interlocks must be in working condition.
- Operating switch gear, tools such as circuit breaker handle, fuse puller, lamp grip, etc. must be readily available and to be used.
- Red tag / name plate indicating high voltage and danger sign should be fitted
- Appropriate ready to use fire extinguishers should be positioned nearby. (CO2 and DCP)
- Charts indicating drill procedures in case of electric shocks must be displayed near MSB.
- Wiring diagram laminated or framed indicating supply system must be displayed nearby.
- All the appropriate spares should be properly preserved and protected, individually packed and identified, and should be readily available for use.
- Earth fault indication should be fitted and displayed in front panel.
- 24 volt battery supply emergency light should be provided near MSB.