PDA

View Full Version : Cost difference of running electric 120v or 220v melting pot



KohlerK91
05-17-2012, 08:44 PM
I was trying to figure out what it cost in electicity to run a 1400 watts 120volt electric melting pot.

1400watts X 1hr= 1.4 kilowatt hour

1.4 kilowatt hours X .08 cents/kilowatthr= 11cents/hour

Is this correct? It only cost me 11 cents to run my pot for one hour?


And what would be the benifit of getting a 220 volt pot?

wymanwinn
05-17-2012, 09:13 PM
I was trying to figure out what it cost in electicity to run a 1400 watts 120volt electric melting pot.

1400watts X 1hr= 1.4 kilowatt hour

1.4 kilowatt hours X .08 cents/kilowatthr= 11cents/hour

Is this correct? It only cost me 11 cents to run my pot for one hour?


And what would be the benefit of getting a 220 volt pot?

watts is watts....whether 120 or 240....you usage is measured in total KiloWatts....

BUT, 240 is more efficient in getting the pot hot....smaller wire too...:bigsmyl2:

dbarnhart
05-17-2012, 09:14 PM
I don't believe there would be a measurable difference. The 110V and 220V pots are probably both the same wattage.

runfiverun
05-17-2012, 09:28 PM
the amperage draw would be smaller.

dpaultx
05-17-2012, 09:42 PM
Only measurable difference would be if that 240V pot was running on 3 phase service.

But I've never heard of a 3 phase pot.

Doug

Fishman
05-17-2012, 10:23 PM
"1.4 kilowatt hours X .08 cents/kilowatthr= 11cents/hour"

It would be less because the heating element cycles on and off

454PB
05-17-2012, 10:56 PM
Yeah there's really no difference in cost to run the pot. What would make a difference is if you already had 240 volts available......installing a new circuit involves additional cost.

One of the reasons automobiles went from 6 volt systems to 12 volt systems was the fact that the wiring could be half the size.

I was messing around with my Lee Pro-4-20 and had a clamp on ammeter connected just to see how often the thermostat cycles. It's carrying current about half the time once it's up to temperature and no additional alloy is added. Also, the wattage rating is fairly accurate on Lee pots, I've checked all three of mine and they are all within 5% of rating.

1hole
05-18-2012, 02:45 PM
Common misconception says 220 AC "costs less to use" but a watt IS a watt and we pay for watts per hour. All a higher line voltage accomplishes is a reduction in the needed wire size to feed a certain load. Thus, if a 110 circuit has sufficent current carrying capacity (and most do) it won't matter a bit. It's hard to justify installing a dedicated 220 line for a device that won't reduce operating costs at all. IMHO.

KohlerK91
05-18-2012, 09:00 PM
Common misconception says 220 AC "costs less to use" but a watt IS a watt and we pay for watts per hour. All a higher line voltage accomplishes is a reduction in the needed wire size to feed a certain load. Thus, if a 110 circuit has sufficent current carrying capacity (and most do) it won't matter a bit. It's hard to justify installing a dedicated 220 line for a device that won't reduce operating costs at all. IMHO.

That is what I was looking for. Thankyou for the imput.

I Just thought would cost more than it does to run a melting pot. But it you break it down to KWH its not that much money at all. Figure it you casted a few hours at a time 4 times a month...........

11 cents per hour X 4hours = 44 cents

44 cents X 4 times monthly = $1.76

Thats alot of bullets for a hobbyiest and with $1.76 worth of electricity

Oreo
05-19-2012, 02:48 AM
The primary reason for using 220v is to have a higher wattage capacity on a single circuit. This is why all your major appliances (>2kw) use 220v. So, if you're one of these guys running two pots at once, it may be helpful. It might be just as helpful to have a second, dedicated 110v circuit run to your casting bench. Figure, your typical wall outlet also has room lighting and the rest of the nearby outlets all on the same circuit. There needs to be enough load capacity left over to run your casting pot or you'll trip a breaker.

slim400
05-20-2012, 02:23 AM
I do not know the exact difference between 110 220. I can tell you when we ordered our master caster originally. Gentleman from magma told me that it costs less to run 220 and that is the way. I went I will tell you gentlemen and ladies this I cast between four and five days a week it is an all-day session lasting 730 in the morning to six in the evening in less than two dollars to our electric is a wonderful thing

Slim400

Danderdude
05-20-2012, 11:04 AM
I own both a 110v and 220v Lee Pro 4-20 and run them side by side.

Both use the same 700w heating element, and when I first plug in and crank them both to full power to melt a full, cold pot, they do so at the exact same speed. There's no difference there.

The advantage is that, with 220v, you can make a longer or thinner extension cord for it compared to the 110v. I hardwired an old piece of 12ga extension cord that had been cut in a shop accident years ago onto my 220v pot, roughly 25ft in length. As it's only drawing ~3.5 amps max, the wire is actually overkill. The 110v gets plugged in to my heavy 8ga extension cord. Again, overkill.

Old Caster
05-20-2012, 11:51 PM
1 Hole is 100% correct that it will make no difference whatever. 800 watts is about 7 amps at 120 volts and the smallest wire used in a house for feeding a receptacle is 15 amp. You should feel OK about your cost for operating your pot for the price you quoted because in Kalifornia it can cost more than double that. In St. Louis it is about 7 cents a Kilowatt Hour. -- Bill --

Catshooter
05-20-2012, 11:59 PM
slim,

The gentleman from Magma lied to you. Unless the 120 volt unit and the 240 volter use different heating element wattage.

This is 34 years of industrial/commercial electrical speaking to you in agreement with the other 12 posts in this thread.


Cat

felix
05-21-2012, 12:28 AM
The big reason, perhaps the only reason, to use three phase is for motors delivering smoother torque while running, and most especially using them in heavy duty starting and stopping applications. Single phase can be used for such applications, but the electronics involved needs to be 1/3 more current ready, and that is what costs money. Usually single phase systems will use DC motors and associated controls, but only when current demands are fairly low, meaning lower torque requirements. Car motors are typically eight horsepower DC types, using gearing to allow for the lower torque requirements. ... felix

runfiverun
05-21-2012, 12:59 PM
thats where slims savings would come from with the casting machine is the start stop movements.
the machine has 8 stations [molds] and the pour mechanism.
is is continously starting and stopping something.

arcticbreeze
05-21-2012, 02:40 PM
The big reason, perhaps the only reason, to use three phase is for motors delivering smoother torque while running, and most especially using them in heavy duty starting and stopping applications. Single phase can be used for such applications, but the electronics involved needs to be 1/3 more current ready, and that is what costs money. Usually single phase systems will use DC motors and associated controls, but only when current demands are fairly low, meaning lower torque requirements. Car motors are typically eight horsepower DC types, using gearing to allow for the lower torque requirements. ... felix


thats where slims savings would come from with the casting machine is the start stop movements.
the machine has 8 stations [molds] and the pour mechanism.
is is continously starting and stopping something.

Although what you are saying is true for 3-phase it is not true for him. He is using 1 phase 220-240vac.

GLL
05-21-2012, 09:38 PM
How in the heck did 3-phase get into this discussion of casting pots? :) :)

Jerry

floydboy
05-22-2012, 03:42 PM
What I like about this thread is the fact that we are not spending hardly any money on our hobby. For some silly reason I always figured I was spending a few dollars for a 3 hour casting session. I feel much better now that I realize it doesn't cost but a couple of dollars.

454PB
05-22-2012, 03:52 PM
I'm paying about 12 cents per KW hour. 3 hours of casting with my Lee Pro-4-20 costs about 25 cents.

Lloyd Smale
05-23-2012, 06:24 AM
correct answer
Common misconception says 220 AC "costs less to use" but a watt IS a watt and we pay for watts per hour. All a higher line voltage accomplishes is a reduction in the needed wire size to feed a certain load. Thus, if a 110 circuit has sufficent current carrying capacity (and most do) it won't matter a bit. It's hard to justify installing a dedicated 220 line for a device that won't reduce operating costs at all. IMHO.

sharps4590
05-27-2012, 05:13 PM
correct answer

Watts
---------------
Amps X Volts


Mix it up any way you want and you can calculate any factor you need. Until you get to 3 phase, then it changes, well, the voltage number will change but not the formula. No need to get into that here.

BD
05-29-2012, 08:31 PM
In theory I accept that a watt is a watt. In practice, I am not convinced. I am not an electrician, and am speaking only from my own experience. I have found that dual voltage motors cost less to run under load over time when wired 220, rather than 110, and that this difference becomes more noticeable as the ambient temperature goes down. I make this observation from years of experience with tablesaws/radial arm saws/planers, and fleshing machines, all in production shop environments. In all cases the motors are started and almost immediately loaded to the max they will take, then shut off as soon as the load is removed. When wired 110, the motors start much slower, (especially when very cold), throw the overheat reset much more frequently under heavy load, and result in a noticeably higher monthly electric bill in the shop.

I have twice converted shops to higher voltage as much as was possible, and in both cases experienced a lower electric bill as a result, along with increased production. I have no idea how this experience would relate to lead melting pots.

The other relevant issue is voltage drop over line length. All of the big portable saws on our projects are wired 220. They just plain "won't cut it" on 110 when run at the end of 100 feet of 12 guage SO cord , and if you went to 10 guage no one would be able to lift the cord out of the truck.
BD

Catshooter
05-29-2012, 09:14 PM
BD,

I am an electrician, more than 34 years worth. And I'm here to tell you that there are things we know about electricity and there are things we only think we know.

I beleive your experience because having read enough of your posts over the years I know you to be an intelligent person capable of observing what's in front of him.

Voltage and amperage are tied together, if you raise one you lower the other. When a motor starts it will draw up to about six times it's running load for a short time while spooling up. If you start a motor at 110 volts it will draw a certain amount of watts to do so. If you then wire it to run off of 220 it will take half as much wattage to get it rolling. I bet in the production environment you're discussing you did see much improvement when going to the higher voltages. Frequent starting is very hard on motors.

This surge during start up doesn't apply to the type of electrical load that a lead pot goes through. When it starts, it starts and it doesn't draw more to do so. In fact I believe it ramps up to full load, rather the opposite of a motor. We use Nichrome wire for heating elements and as they heat up their resistance increases until it stabilizes.

Electricity is weird stuff. Anyone who claims to understand it all is a fool. One of the first sentences in the American Electricians Handbook is that we really don't know what electricity is. The theories about it are just that, theory. Fancy guesses that may work. Twice in my career I've seen electricity do "impossibe" things. Flew straight in the face of current theory.

Voltage drop over cords is a very real problem and what you say is total fact. I measured a heavy duty skilsaw's start up amperage once, it was over 65 amps. When you try to do that at the end of a 100 foot 12 gauge cord the voltage drops waaaaaay down, forcing the amps even higher to the point where there just isn't enough volts to cause the motor to spin.

In theory, theory and practice are the same. In practice, they most definatley are not. A lot of engineers forget that. :)


Cat

454PB
05-29-2012, 09:44 PM
Agreed.

All conductors have resistance, and the longer the wire, the more resistance.

While I still worked in power generation, we saw examples of this all the time. String out 300' of #12 wire and apply 120 volts to one end, measure at the other end and you'll see very little voltage drop. Now add a load, and you'll see a lot of voltage drop, sometimes to the point where the electrical device won't even operate or will begin to heat.

That doesn't mean the wattage has changed, it means you have introduced additional resistance via the long conductor. It's the reason power transmission lines utilize high voltage through small conductors to move electrons from the source to the load, then use transformers to reduce the voltage and raise the amperage.

popper
06-06-2012, 10:10 AM
No advantage to a 220 pot at all, unless you are a commercial operation.

MrXrings
06-07-2012, 03:12 PM
I have one of those kill=a=watt meters in my shop and plugged my pot into it a it ran for about an hour, currently we pay about 10cents per kwh here and it showed 4 cents of power used so that would take into account the warm up and the cycling once the pot was to temp. Cheaper than I thought too. Power is power makes no difference 220 or 120v. Watts equals voltage times current, you double the voltage and it cuts the current in half and vice versa, there is no free lunch.

41mag
06-08-2012, 05:10 AM
Well I can honestly tell you that when after pouring several times a week for a month or so when I started I didn't hardly notice any change what so ever in my bill. When my nephew moved in with us in order to be close to the job he landed, I noted it went up an extra 50-75 bucks.

After that I had a REAL good conversation with him about leaving lights on, and doors open, when he was either out of the room or outside smoking. After the little get together, the bill has now dropped back into the same general area it had been.

No telling how much I have saved over the years since my daughter has moved out, but it has probably all been spent up on reloading or casting accessories.

yobohadi
06-11-2012, 05:23 PM
Lets forget about a long length of wire to deliver the power and pretend your outlets are just a few feet from your Main breaker and you measure 110 Volts and 220 Volts at your outlets...

Watts = Volts X Amps

A 700 Watt Element run on 110 Volts will use ~6.36 Amps.

A 700 Watt Element run on 220 Volts will use ~3.19 Amps.

They will both use the same Watts the only difference really will be that you can run 3 pots on a 110V 20Amp circuit.

Whereas you can run 6 pots on a 220Volt 20Amp circuit.

So the only cost difference is 3 more 220 Volt pots. :)

alamogunr
06-16-2012, 08:38 AM
I saved $$ with a 220V(230V?) pot. A few years ago, Midway had a clearance on RCBS ProMelt 220V pots. I saved about $50-75. I already had a 220V outlet in the shot for my table saw so I cut off the European plug and wired the same plug as the saw used on the pot. The HVAC unit in the shop uses way more electricity than either the ProMelt or the Lee Pro 4-20.