Thursday, February 6, 2014


Bureau of Energy Efficiency has come up with ECBC guidelines which includes transformers.


Power distribution companies have started measuring the consumption of energy through KVAH units in place of KWH units.

Increased power bills due to poor power factor. Bills are getting inflated from 1.25 times to 6 times. 

One reason is low power factor of existing transformers at No Load condition. Most of the industries are working in one shift only. During night hours transformer is not loaded and power factor shall be less than 0.2, Due to this poor power factor energy bills in night inflates by more than 5 times depending on the type of transformers.

Installation of Energy Efficient transformers and replacement of existing transformer by Energy Efficient transformers, as no load power factor is much better in Energy Efficient transformer i.e P.F at no load condition is 0.5 Approx.

For judgment of cost effectiveness of Energy Efficient transformer we can take the help of following illustration:

We can take the example of 1000KVA existing transformer:
A) 1000KVA 11/0.433KV transformer 
No Load Power Factor 0.15
No Load Loss : 2.12KW
Therefore total units consumed by transformer  = 2.12 /0.15
                                                                     = 14.13 KVAH
Total Units consumed by transformer in a year during night hours = 14.13 x 10 x 30 x 12
                                                                                      = 50868 KVAH
                                                                                      = 50868 x 7= Rs. 3,56,076 per year

After replacement of the same transformer by our HEFF model transformer the energy bills for night shift are as below:
B) 1000KVA 11/0.433KV transformer 
No Load Power Factor 0.5
No Load Loss : 1.02KW
Therefore total units consumed by transformer =1.02 /0.5
                                                                   = 2.04 KVAH
Total Units consumed by transformer in a year during night hours = 2.04 x 10 x 30 x 12
                                                                                       =7344 KVAH
                                                                                       = 7344 x 7 = Rs. 51,408 per year
So we can see from above illustration that we can save up to Rs 3.0Lac per year after installation of our HEFF model transformers. 
In a plant where working hours is 24 hours, there may be the possibility  that some machines may be in off condition and due to which load may be decrease by approx. 50%, in that conditions HEFF model transformers are suitable for saving the energy as well as also helps us in reducing energy bills. We can take the one example of 1000KVA transformer for illustration purpose.

A) 1000KVA 11/ 0.433KV normal transformer 
No Load Loss : 2.12KW
Load Loss : 11.915KW
Therefore total losses of transformer @ 100% Load : 2.12 + 11.915 = 14.035KW
                     Total losses of transformer @ 50% Load : 2.12+2.98 = 5.10 KW
      Value in rupees pay in form of energy bill at 50% load : 5.1x12x30x12x7 = Rs, 1,54,224/-
      Value in rupees pay in form of energy bill at 100% load : 14.035x12x30x12x7 = Rs, 4,24,418/-

B) 1000KVA 11/ 0.433KV HEFF Model transformer 
Total losses of transformer @ 100% Load : 9.80KW
Total losses of transformer @ 50% Load : 3.00 KW
       Value in rupees pay in form of energy bill at 50% load : 3.0x12x30x12x7 = Rs, 90,720/-
       Value in rupees pay in form of energy bill at 100% load : 9.80x12x30x12x7 = Rs, 2,96,352/-

So from above calculation we can conclude that with using of HEFF Model transformers we can save huge amount on our yearly energy bills which are as below:

a) At 50% load : Rs.63,504/-
b) At 100% load : Rs. 1,28,066/-

For having a detailed analysis of a plant requirement for selecting a transformer model we have designed a format which can be used to select model. The format is as below:


Name of Organization


Contact Person

Mobile No.

E Mail Address

Product Manufactured

1)       Connected Load

2)       Sanctioned Load

3)       Total Running Hours of Factory/ Industry

4)       Peak Load in Amperes

5)       Running Hours of Peak Load

6)       Power Factor at Peak Load

7)       Power Factor- Average of Month

8)       Minimum Load in Amperes

9)       Running Hours of Minimum Load

10)   % of Energy Cost in Final Product

11)   Product Details

a)       Engineering Process

b)       Chemical Process

c)       Continuous Process       

If you have any enquiry regarding transformers visit our website
contact us at


At February 7, 2014 at 3:28 AM , Anonymous Anonymous said...


At February 7, 2014 at 3:33 AM , Anonymous Anonymous said...

please explain the calculation of no load losses considered in the illustration. for HEFF the power factor has improved to 0.5, plz elaborate.

At February 7, 2014 at 10:51 PM , Blogger Sai Electricals said...

Thanks for your feedback.
We are having low no load loss & low no loss current by using better core grade material and improved flux densities.This also improves power factor at no load.

At February 8, 2014 at 3:54 AM , Blogger Tabassum Naaz said...

very nice article

At February 9, 2014 at 8:27 AM , Anonymous saqlain said...

wht is the reason for decrease in losses, amorphous core i guess, plz explain

At February 28, 2014 at 11:10 PM , Blogger jayant chaudhary said...

really good very informative article


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