Chennai Metropolitan Water Supply And Sewerage Board Tender

Supply and delivery of submersible centrifugal sewage non-clog pumps, vertical spindle type pump , wear resistance with submersible motor for the various duty conditions. Pump shall be capable of handling min 100 mm solid size with sewage specific gravity of up to 1.05. Pump shall be of robust construction, Liquid passages shall be finished smooth and designed as to allow free passage to solids. Pump Impeller should be of Non-clog semi open type , single vane / multi vane preferably contra bloc or vortex impeller design. Double mechanical seal with silicon carbide faces should be provided to protect the motor from ingress of sewage along the shaft. The critical speed of the rotor shall be atleast 30% above the operating speed. Pumps should have double bearings between the pump & motor. The bearings life shall be minimum 100,000 hrs of operation with greased for life. Pump should be provided with automatic coupling device including pedestal, duck foot bend, stainless steel guide pipe or related accessories of suitable size to facilitate lifting and lowering into guide rails for easy maintenance. Pump shall be provided with a stainless steel lifting chain conforming to BS 970 Gr 304. Pump speed shall be of 9600 rpm for high duty pumps and 960/1450 rpm for low duty pumpsets. Casing and impeller should be of CI Gr. FG 260:IS210 more preferably with hardened impeller.Shaft should be of stainless steel AISI 410. All the fasteners and bolts shall be of AISI 410.The submersible motor shall be operated with 3ph, 415 V(+or– 10%), 50Hz(+or-5 %) dry induction type. Motor shall be capable of giving rated output without reduction in the expected life span when operated continuously. The rotating assembly shall be dynamically balanced as per standards. The starting current of the motor shall not exceed 200% of rated full load current for Star / Delta or ATS starting under any circumstances .

The motor shall be suitable for full voltage star delta / ATS starting. The locked rotor current of the motor shall not exceed 600% of full load current unless otherwise specified. Motor shall be designed to withstand 120% of rated speed for two minutes without any mechanical damage, in either direction of rotation. The motor vibration shall be within the limit specified in applicable standards . Motor should be of IE2,explosion proof compatible for VFD operation together with star-Delta /ATS starter, protection against increase instator winding temperature (15 deg Celsius), bearing temperature, leakage in the stator housing and terminal box shallbe provided and to be suitably interlocked with the control panel for tripping the pump in case of increase intemperature beyond set limit. Insulation class shall be of “Class H” and degree of protection shall be of IP 68 as per IS4691. Motor shall be suitable for continuous operation in fully submerged or partially submerged condition.The pumpset shall be supplied with power cable of PVC insulated and PVC sheathed, copper, flexible, round type with required conductor size and number of cores as per starting method and of specified length for continuous use under water and air. The control cable of PVC insulated, PVC sheathed, flexible for stator winding temperature sensor 3core x 1.5 sq.mm copper conductor and for bimetallic switches 2core x 1.5 sqmm copper conductor shall be provided. Motor shall be supplied with 10m of round submersible copper cable of suitable size. The non clog submersible pumpset shall be provided with suitable starter control panel having all protections as mentioned above.(upto 5 HP - DOL Starter, above 5 HP to 25 HP -Star Delta Panel and beyond 25 HP shall be ATS) 14 mtr head, head of Discharge 400 to 500 M3/hour.

Supply and laying of 3.5 core 95 sq.mm LTUG cable