# Electric Cost For Molder

07/17/2014

From original questioner:

We just purchase a SCMI Compact 23 and a Dustek dust collector, and I was just wonder if any knows the average electrical consumption for these machines per hour of operation

From contributor La

Assuming I did this correctly, Our molder has 65hp the dust collector & valve 16=81hp using the online calculator for hp-kw I got 60kw if my electric rate is \$0.10/kwh my cost is about \$6/hr. This isn't entirely true because likely I'm not running all the motors to their full hp rating. But even a motor running at idle uses about 50% of it's rated energy. New motors are required to be more efficient than the old ones. So depending on the age of the motors and the relative efficiencies I think you could save up to 5% of the power cost. Maybe \$0.30/hour. Doesn't sound like much until you consider that's \$300 for every 1000 running hours @ full bore.

From contributor Le

Don't forget the demand rating when you turn this thing on the first billing of the electrical month.

From contributor La

Leo is right. If you are on a demand meter, give a little time between each motor start. Motors pull a lot more amps on start-up than when running. When the motor has come to full speed the peek demand is over.

From contributor Le

Demand (around here at least) works on a 15 minute cycle. So the immediate draw of the motors won't make that much of a difference. I've gone through the discussion of having VFDs on motors and bringing them up slowly to prevent the demand spike and was told it won't make a difference because it is based on a 15 minute interval.

From contributor Ga

Why I asked this question is because I'm in a mill complex and I pay my electric bill to the complex. They told me that my multiplier is 200 on my meter so every khw shown on the meter it counts for 200 kwh.The first month I had these machine in operation. The bill was for 3600 kwh my rate is .19 per kwh that comes out to 673.00 . I must of used those machines for no more than 10 to 15 hours that is being generous. So I started keeping a log. Last Saturday the meter read on 232 and when I left this Saturday the meter read 238 which is 6 kwh on the meter and a total on 1200 khw x .19 = 228.00 and I only used the machines for a total of about three hours(again this is generous) that is about 76.00 an hour . I think the multiplier is incorrect or the meter is connected wrong. To get the power they tapped into an elevator line 600 volts 3PH They installed a 118 KVA transformer to reduce the power to 230V 3PH. Not knowing much about this I'm just trying to get an average kwh machines will draw

From contributor La

Boy, Something seems wrong with that billing system! 200 times & \$0.19/kwh! Yikes. You'd better find a different place for you shop.
Our demand time here is 30 minutes. Our price per KWH is \$0.10.
Running a 17 man shop our bill is about \$1800/ month.

From contributor Je

Larry,

The multiplier doesn't mean you're paying 200x what you actually use. It means the meter output is 1/200th of the actual use. Our meter multiplier is 240. Our load is usually about .41 x 240 = 98.4 kw.

On you meter when it reads 1 kwh it means you consumed 200kwh. It doesn't read 200kwh and mean you only used 1kwh.

Jerry

From contributor La

Sorry for the mistake JC. But something is still very wrong. Contact the electric company about it.

From contributor Le

Do you have a demand meter? Because that'll really bump up the price of electricity. Most 3 phase is commercial and most commercial is by demand meter.

In my shop I have a demand of about 8kWh. They give me 2 kWh so the demand charge is 6kWh. But by the time you add up all the crap they put on the demand lines it's about \$20/kWh. So when I use \$60 of electricity at 9.9 cents kWh my demand adds another \$160 to the bill. It sucks, but that's the way it is.

And if you are running 80kW of motors you are gonna have a big demand factor.

From contributor Ma

Gary,

It may be that the complex you're paying your electric to that is stiffing you and not the power company.

Talk to the power company and get to the bottom of it.

What part of the country are you in where electric is \$.19 per KWH? I'm glad I don't have to pay those kind of rates.

Mark

From contributor Ga

I had the company that does the billing for the complex out today. He said the meter was hooked up incorrect after they made the changes there was still a load on it of 3kwh. He said that it is the transformer in stand by. That works out to about \$560.00 a month with no machines running. I told them they need to put in a disconnect so I can shut the transformer off when not in use. He did say that the molder should cost about \$6.00 an hour to run. Marc I'm in Rhode Island that is something I'm looking. I'm not sure what the rate is that the complex pays, but I live in the next town over and that is in Massachusetts I pay about .16 per kwh at home. A little pricy out here

From contributor La

If you are the only user on that transformer it would pay you to have an electrician put a disconnect on it.

From contributor Le

That meter should be on the secondary of the transformer so it only shows power you use. The power the transformer uses should be dealt with in there transmission charges, not a direct kWh charge to you.

From contributor La

Leo, could be a transformer in the building, not the utility one. Some properties distribute to individual users @ 480 then step down to 208/120 internally. We've got an assortment of transformers in our building. If they are in our shop & on equipment not being used I can shut the breaker off to them to save the energy wasted as transformer heat.

From contributor Ga

Thanks eveyrone for all the insight on this. Larry you are correct the building is 600v and the transformer took it down to 230v. This is in our space for our machines. They are going to install a disconnect for me so I can shut the transformer off . I will let you know how I make out with this again thank you very much