H.V. Discharge Lighting Equipment

H.V. Discharge Lighting Equipment

Every High Voltage discharge lighting equipment & installations shall be rated for voltages not exceeding 5 KV, RMS to earth, measured on open circuit and shall comply with BS: 559.

H.V. discharge lighting equipment, including neon signs for advertising or any other purposes, shall not be installed without prior approval from DEWA.

7. Safety and Emergency Light Fittings

The source of supply for safety lighting shall be either maintained or non-maintained type as appropriate to suit individual applications.

All electrical switch-room and operational areas shall be provided with adequate number of emergency light fittings.

The safety and emergency light fittings installed shall comply with BS. 5266 and shall be rated for a period not less than 3 hours continuous operation.

The light fitting/s shall normally incorporate necessary battery and charger within.

The safety light fittings shall also incorporate appropriate signs in Arabic and English such as 'EXIT' and directional arrows, as applicable to individual locations.

7. Electric Motors and Starters

Control of Electrical Motors shall comply with BS EN 60204, if the equipment is within its scope

Motor control circuits shall be designed so as to prevent any motor from restarting automatically after a stoppage due to a fall in or loss of voltage, if such starting is liable to cause danger.

Where safety depends on the direction of rotation of a motor, provision shall be made for the prevention of reverse operation due to, for example, reversal of phases.

Installation of 1-phase motors rated up to 3.7 KW (5HP) and 3-phase motors up to 110 KW (150 HP) only shall normally be permitted unless otherwise approved by DEWA. Where a large number of motors above 150 HP are proposed, the advice of DEWA shall be sought on availing a bulk supply.

All electric motors shall be adequately protected against overload, short circuit, earth leakage and additionally, against loss of one or more phases, voltage fluctuations, etc. as deemed essential to suit individual applications.

Starters shall be provided with overload relays of the thermal type with automatic compensations for variation in ambient temperature between 2.8 ^oC and 48 ^oC.

The starting equipment to limit the current may consist of any of the following type of device or other approved by DEWA.

1. 
   Adjustable speed drive
   
2. 
   Intelligent controllers
   

All motors shall be provided with an isolator, for isolating the motor from the supply during periods of inspection or maintenance. Such means of isolation shall effectively interrupt the supply on all phases. The isolator may be integral with the control gear or separate, but shall be in close proximity to the motor. An emergency stop push button shall be incorporated in the control gear.

When motor starting gear is energised from an auxiliary circuit, the circuit shall also be isolated during maintenance.

All starters, isolators and push buttons shall be clearly marked in Arabic and English stating which machine they control and their function. To avoid confusion, the words 'START' and 'STOP' and not 'OPEN' and 'CLOSED' shall be used.

Motors and their control gear shall be located in well ventilated areas with adequate space for operation, inspection and maintenance.

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