A building has a 35 kW transformer that is connected all the time. A local electrical contractor indicates that the core losses from comparable transformers are approximately 4% of rated capacity. Assume that the electrical costs are 9 c/kWh and 9 USD/kW/month of peak demand, that the average building use is 8 h/month, and that the average month has 720 hours. Estimate the annual cost savings from installing a switch that would energize the transformer only when the building was being used. The transformer is used h/month, and it can be turned off for the remaining of the month. That is h/month. That means the transformer can be turned off for h/year. The core losses from the tansformer is kW. Installing a switch to turn on the transformer only when the building is used results: Annual energy savings of kWh/year. Annual cost savings of USD/year. Does it make sense to use this strategy?

A building has a 35 kW transformer that is connected all the time. A local electrical contractor indicates that the core losses from comparable transformers are approximately 4% of rated capacity. Assume that the electrical costs are 9 c/kWh and 9 USD/kW/month of peak demand, that the average building use is 8 h/month, and that the average month has 720 hours. Estimate the annual cost savings from installing a switch that would energize the transformer only when the building was being used. The transformer is used h/month, and it can be turned off for the remaining of the month. That is h/month. That means the transformer can be turned off for h/year. The core losses from the tansformer is kW. Installing a switch to turn on the transformer only when the building is used results: Annual energy savings of kWh/year. Annual cost savings of USD/year. Does it make sense to use this strategy?

Power System Analysis and Design (MindTap Course List)

6th Edition

ISBN:9781305632134

Author:J. Duncan Glover, Thomas Overbye, Mulukutla S. Sarma

Publisher:J. Duncan Glover, Thomas Overbye, Mulukutla S. Sarma

Chapter3: Power Transformers

Section: Chapter Questions

Problem 3.57P: A two-winding single-phase transformer rated 60kVA,240/1200V,60Hz, has an efficiency of 0.96 when...

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