KVA, KWH...?????? Help

[Nemo5150]

Can anyone shine a light on this for me...
I need to find out what KVA is being used in our factory (boss has asked)
How do I work this out?

 

[Silly Sausage]

Read the meter.
Record the readings each day for a week or so then work out the average daily usage.

 

[Nemo5150]

So far I have 33610Kwh for the month, I divided this by 720Hrs to get 46.6Kw I used a power factor of 0.9 and divided the 46.6Kw and ended up with 51.7Kva is this the correct way to do it?

 

[ezzzekiel]

Kva = Kw / Pf

 

[Engineer54]

So far I have 33610Kwh for the month, I divided this by 720Hrs to get 46.6Kw I used a power factor of 0.9 and divided the 46.6Kw and ended up with 51.7Kva is this the correct way to do it?

I think you being just a tad over optimistic, thinking your factory is running at a 0.9 power factor. Unless of course you have a very well set-up capacitor PF correction bank???

 

[Electro-tech]

What type of meter as , if your boss is trying to assess electricity costs then more answers would be on the Electricity Bill.
ie; charges for imported power, if no PFCorrection and then there is I2R losses of Installation.

 

[Nemo5150]

Thanks Engineer54, there is absolutely no chance that we would have "well set up capacitor PF correction bank" factory is very old. with your experience could you suggest a more realistic figure or Is there an easy way to determine the power factor?

 

[Engineer54]

Without knowing what you have in this ''very old factory'' ...ie, sizes and the state of the motors etc, as well as the installation, i wouldn't even be able to give you a guesstimate!! ...lol!!

What i would suggest to you, is to get your boss to hire a recording power analyser for a week... These units will give you and you're boss a pretty accurate account of power consumption and costs, as well as many other factors, including your overall PF level....

You could even use such a unit to measure individual motors or machines, that may show-up a need for much needed maintenance/refurbishing... Personally, i think every maintenance dept of manufacturing establishment, should be in possession of such an instrument, they can save an awful lot of money in more ways than one....


So if i was you i'd put it too your boss in the first instance to hire one, and then later, after he has seen the benefits, go for the purchase of such a unit!! But they can get rather expensive, but you don't need a top of the range model!!!

 

[Nemo5150]

Many Thanks for your help!!

 

[Electro-tech]

I maybe wrong but I thought the Network was based on 0.85.

 

[Engineer54]

I maybe wrong but I thought the Network was based on 0.85.

You can always live in hope i suppose!! lol!! Unfortunately in the real world you can often find, (especially in industrial installations) PF's considerably lower than 0.85. Which is why you have PF correction banks connected to main switchboards and the like!!