Electric Question ( Help !!! )

(1) A heated swimming pool has two heating elements, each rated at 10 KW, 230 V. The pool also uses a 1 KW filter pump. It takes 8 hours of running the heating elements continuously to get the pool up to right temperature

If electricity costs 15 cents per unit ( 1 unit = 1 KWH ) , what is the cost of the electricity required to heat the pool and run the pump ( for 8 hours ) ?

My answer : (0.15 cents ) ( 8 hrs ) ( 60 minutes ) = $72.00

(2) What is the combined current drawn by the pool heaters and pump from the 230 V supply ?

( I'am not sure of this one !!! )

Please dont just state the answer need explanations as well.

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Comments

Inc

You really don't like homework, do you?

http://en.wikipedia.org/wiki/Kilowatt-hour

RussS

Depends whether you are with Genesis or Mercury Energy

moss12

meh I will ask the teacher for help on monday

thanks for the help

Plantwiz

moss12 wrote:

meh I will ask the teacher for help on monday

thanks for the help

Good plan

for a moment there I though I was on the landscaping forum

emmajoyce

I will try to steer you in the right direction.
You have to take into account that you have two heaters running for the eight hours not just one.
Also you have to take into account that you have the pump also running at 1kw for eight hours
As far as the second question, it seems to be just a simple equation problem. Maybe something like ohm's law. I cant remember which equation. Ill leave that for you to look up. you have to figure up what the amperage is. this shouldnt be to tough

moss12

thanks emmajoyce man sadly I have to take this paper even though majoring in network engineering

sprkymrk

I think your first equation should be:

(10KW+10KW+1KW) x 8 hours x .15 cents = $25.20

Because you have 2 elements and 1 pump. A KW hour is the cost of running something at 1 KW for 1 hour.

The second question uses Volts x Amps = Watts
Current is the same as Amps.

But it would look something like this:

230 x A = 10,000 for each element, and we'll assume the pump is 230 x A = 1,000.

Basic math tells you to figure it out like this:

10,000/230 = A or rounded to 43.5 (not sure how far you need to round it) and
1,000/230 = A or rounded to 4.3

43.5 + 43.5 + 4.3 = 91.3 Amps

HTH