<i have several 75kva 600v 3 phase transformers and a couple 45 kva 600v 3phase transformers.

Can someone tell me how to calculate the wattage of these?:vs_worry:

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<i have several 75kva 600v 3 phase transformers and a couple 45 kva 600v 3phase transformers.

Can someone tell me how to calculate the wattage of these?:vs_worry:

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The power is already calculated. 75kVA and 45kVA. This sounds like a commercial installation...

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5,832 Posts

The "VA" stands for watts

So 1000 X 75 = 75,000 watts

1000 X 45 = 45,000 watts

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428 Posts

VA does not stand for watts.

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The power you are paying for is what is connected to the transformers.

You can have these transformers, but not use the full capacity of them.

What kind of business is this?

How much more is the bill than before?

Have you contacted the power company?

The operating Watts is Watts out = Watts in. This is determined solely by the load downstream of the transformer. This can be anywhere from zero on up.

The parasite rating is Watts in and 0 Watts out. This is what the transformer 'wastes'.

In actual operation, Watts in will always be higher than Watts out. This is because all transformers produce heat and this heat comes from Watts in but is not converted to Watts out.

In my experience, the parasite load of a 45KVA transformer is roughly 10 KWhrs per day. a 75 would be about 15.

The amount billed will never be less than the parasite load, and any amount more than parasite is actual usage.

Lets say you have 3 - 75s and 2 - 45s. That's roughly 65 KWhrs per day, or nearly 2000 KWhrs per month plus the actual usage. If you're paying 10¢ per KWhr, that's $200 a month as an absolute dead minimum. Add the actual usage on top of that and you can see why it's expensive.

Rob.

P.S. Unless you're being billed for VARs or low Power Factor, VA (or KVA) has nothing to do with the bill, it's all Watts.

the VA x Power Factor = watts. PF is less than 1.

<i have several 75kva 600v 3 phase transformers and a couple 45 kva 600v 3phase transformers.

Can someone tell me how to calculate the wattage of these?:vs_worry:

I simple form VA stands for Watts. I don't care how you want to twist it. So then in my calculation is the xfrmr 75000 watts and 45000 watts or do you come up with something else???? Give me a break.VA does not stand for watts.

Incorrect. "The ratio between the VA (i.e. rms volts time rms amps) and Watts is called the power factor PF. In other words, volt-amps x power factor = watts. Similarly, KVA*PF = KW, Or kilovolt-amps times power factor equals kilowatts."

The "VA" stands for watts

So 1000 X 75 = 75,000 watts

1000 X 45 = 45,000 watts

http://www.rapidtables.com/calc/electric/kva-to-watt-calculator.htm

It never has stood for watts. As for a break, yeah you will get your chops broke and ribbed for a while by some of the sparky's. Just let it roll and laugh. All of us have had brain farts every now and then. Sometimes stating it on a forum not how you are thinking of it in your head, comes out a little wrong. You just have to do the math on this one.I simple form VA stands for Watts. I don't care how you want to twist it. So then in my calculation is the xfrmr 75000 watts and 45000 watts or do you come up with something else???? Give me a break.

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The net effect is that a transformer rated at say 1000VA will only be able to deliver 1000 watts when the circuit has zero reactance. Typically, the transformer will be able to deliver less than 800 watts (real power). For a good discussion about apparent power, true power, reactance, capacitance, inductance, see http://whatis.techtarget.com/definition/volt-ampere-VA.

None of this is relevant to the question of why the OPS has a higher than normal power bill, as the losses through transformers are not likely to contribute a significant amount to the monthly power bill. There may be complicated factors such as time of day billing or peak demand billing that are impacting the bill, but unless there is something wrong with the transformers, the lost power through the transformers is a small but unavoidable cost of transforming voltage.

A huge bill in your hand, could be not so large in someone else's. When a transformer are looked at as a certain percentage of loss from the stepping up or down, the energy loss is converted to heat or BTU's. That is why you see the radiators on them.Hi All recently <i got a huge electrical bill and am now trying to figure out where <i am using all the power. <i have figured some of the usage but am trying to figure out how to determine the wattage of several transformers that <i have.

<i have several 75kva 600v 3 phase transformers and a couple 45 kva 600v 3phase transformers.

Can someone tell me how to calculate the wattage of these?

The loss of power from transfer is already calculated by the power company, when they bill businesses so much per kWh.

"Typically, the total losses for a 75 kVA transformer are about 1,000 W at 35% loading or 1.3%. The actual losses when the transformer is fully loaded can be more than 3,000 W for linear loads and 7,000 W for nonlinear loads. This amounts to 4% and 9.3% respectively—considerably more than the NEMA TP-1 table for minimum efficiencies for a 75 kVA transformer. While the overall concept for requiring more energy-efficient transformers is quite good, engineers may want to be very careful about transformer selection when the anticipated operating conditions do not match the base criteria that were used in developing the TP-1 table."

http://blog.schneider-electric.com/...ncy/2013/03/25/how-big-are-power-line-losses/

http://www.csemag.com/single-articl...-losses/84a7466f05abe1341ddb4b5a402249e9.html

Transformers are going to always use some amount of electricity, regardless if you have a load on them that is off. Think of it like a garden hose waiting to be turned on.

http://www.copper.org/environment/sustainableenergy/transformers/education/trans_losses.html

You have to remember a little thing called Ohm's law. No one is twisting it around, except that you are not calculating it correctly. Yes watts is the energy, which is converted to BTU's. That is why during the Summer months when it is really hot outside and everyone wants to run their A/C, they have to cool the suckers off, otherwise you can fry eggs on them.I simple form VA stands for Watts. I don't care how you want to twist it. So then in my calculation is the xfrmr 75000 watts and 45000 watts or do you come up with something else???? Give me a break.

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A much simplier answer -

<i have several 75kva 600v 3 phase transformers and a couple 45 kva 600v 3phase transformers.

Can someone tell me how to calculate the wattage of these?:vs_worry:

va = w

K = 1000

so 75kva = 75,000W.

&

45Kva = 45,000W.

Is this what you wanted to know ?

if not please elaborate.

:vs_cool:

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What was your low bills KWHR?

What is the high bill KWHR?

What is your rate per KWHR?

Do you have a power factor penalty?

Do you have a demand charge?

My old license plates

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