PACKAGE : I Bid Document VOLUME : II - Public Health Engineering

Contactors:
The three pole contactors with minimum of 2 No. + 2 NC working contacts and one
number of 1 No + 1 NC spare contact shall be used. The contact made of anti-weld
silver cadmium shall be designed to give minimum bounce to ensure long contact
life. The rating of the contactor shall suit the motor and capacitor circuit duty. The
contactor shall be suitable for 415V, 50Hz, AC 3 phase duty in respect of making
and breaking operations at specified power factors. The contactors shall conform to
IS:13947 Part-1 and Part-4.
Single Phase Preventor:
The single phasing preventor shall be provided for all 415 V, motors above 5 kW
rating. The single phasing preventor shall be current operated type using minimum
current detection/negative phase principle. Necessary current transformers shall be
provided to suit the requirement of the single phasing preventor. The single phasing
preventor shall be stable during the starting of the motor. The maximum operating
time to the single phasing preventor shall not exceed 2/3 second even in the starting
condition of motor.
15.13 Cables and cable laying.
Following type of cables shall be used.
1. For LT Power Supply : 3½ core, 3 core or 2 core 1100/600 V PVC
insulated PVC sheathed armoured cables.
2. For control cables : Multicore copper cable minimum 2.5 mm 2 with
PVC insulation, armoured and PVC sheathed.
3. Submersible Motor cable : According to Manufacturer
The minimum size of control cable shall not be less than 2.5 mm 2 .
All cables shall be suitably de-rated for grouping and higher ambient temperature.
The cables shall conform for LT to IS:1554 - Part I and for HT to IS 1554 -
Part - II., IS: 7098.
GTS : General Technical Specification. Page 115