Agenda - Council - 03/26/1996 - Laserfiche WebLink

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------ ----- ..... a --- A VFD and premium efficiency motor are proposed to permit changing the pumping rate of Wen ' No. 1. The VFD provides a very efficient method for varying the speed of the pump. A premium efficiency motor is proposed for the following reasons: 1. Recommended because of electrical stresses created by the non - standard voltage wave shape generated by the variable frequency drive. 2. Has lower losses than a standard motor. ' 3. Qualifies for a $2.50 per horsepower rebate from Anoka Electric Cooperative. ' Because a VFD is the most efficient method of pumping at different flow rates, the VFD qualifies for a $20.00 per- horsepower rebate from Anoka Electric Cooperative. The total rebate from Anoka Electric Cooperative for a 75 hp. Motor will be $22.50 per horsepower which equals $1,687.50. The estimated cost of the variable frequency drive is $9,000.00. In addition to the variable frequency drive, a 200 amp. feeder breaker, new power wiring and new ' control wiring vyill be required. The cost of the above items plus mounting the variable frequency drive is estimated to be $9,200.00 ' An advantage of pumping at a reduced flow rate during months of normal demand is keeping the electrical demand charges to a minimum. Instead of paying the demand charges for a 75 hp. motor for 12 months, these charges may be for only three of four months. The charges would be reduced for the other eight to nine months when the pumping rate and motor load are significantly lower. ' Another area of reducing electrical costs is the time of day rate for reducing the electrical load between 4:00 p.m. and 10:00 p.m. each day. These cost savings are presently being reviewed. The total estimated construction cost is as follows: 1 Remove existing pump $ 1,800 Construct base & piping revisions 2,000 Furnish and install new pump 16,500 Variable frequency drive 9,000 Electrical feeder and installation 91200 ' Total estimated cost $38,500 W3