Motor loads calculation

24/07/2012 by 18 Comments

On my last post,i discussed about why we need to determine motor loads and efficiency.So for this post i want to share how to get the motor load value using simple calculation electrical formula.

Before we go further,i want to explain about Power.What is meaning of Power?Of course this term is significant with our discussion topic.Power is rated of energy in electrical circuit.

It is combination from Amperage and Voltage value.Basic formula for Power is P (watt) =I(ampere)  x V (volt).Power also measured in Horsepower (hp) unit.For common conversion from electrical Horsepower to Watt is 1hp = 746 watt. read more

Filed Under: Electric Motor Tagged With: , , , , , ,

Transformer rating

20/06/2011 by 2 Comments

Transformer rating or capacity depend on the  limited of insulation temperature can stand for maximum load.The ratings can be up or down when we reducing a  core and copper losses.

To reduce core and cooper losses,we can improved the rate of heat exchange with proper cooling system or by improving quality transformer insulation that can stand for high temperature.

For larger transformer types,we can remove more heat with increased area for efficient cooling and increased volume of oil to absorb more heat to reduce the temperature. read more

Filed Under: Theory Tagged With: , , , , , ,

UPS batteries charging rates

18/05/2011 by 2 Comments

Basically charging rates for UPS batteries depend on type of batteries cell such as Lead-acid (Pb) or Nickel Cadmium (NiCd).This two types of batteries cell have a different method to charging up.

For Lead-acid (Pb) cells is used a ‘constant voltage’ method.It mean where the current varies as the state of charge changes.Different method for Nickel Cadmium (NiCd) cells,it  is used ‘constant current’ where the cell voltage varies as the state of charge changes.

When we try to charging batteries  from  Lead-acid (Pb) cells type,the basic process are from a constant voltage source the charging current starts high and slowly decreases to a constant value when the cells become fully charged.The constancy of the current is an approximate indication that the cells are fully charged. read more

Filed Under: Theory Tagged With: , , , , , , ,