Best method of calculating cost per run for electric heat treat furnace

[milemaker13]

We want to gauge the cost of electricity per run of our new heat treating oven. Its a small (24x24x48 aprox retort) box oven powered by a 70 amp 480 volt 3 phase breaker.

The control allows for ramp up/down of temps over long periods of time. A typical run lasts 16-20 hours depending on the parts being annealed. What is going to be the best way to measure/meter/calculate the total watts consumed for cost estimating purposes?

I need to gather more info, such as total element watts. A simple formula such as, oh say 1000 watts x 16 hours won't work well since I won't know what element zones are on/off during the cycle. The control decides how much juice based on the heat treat recipe. Mmmmmm, juicy heat treats. AAaaggggggaa.....(drool)

This is a brand new Honeywell control, so now I'm wondering if it can give me some usefull zone info...

What about a stand alone electric meter? That's probably the only real way to track it....

 

[Iron_Ben]

We want to gauge the cost of electricity per run of our new heat treating oven. Its a small (24x24x48 aprox retort) box oven powered by a 70 amp 480 volt 3 phase breaker.

The control allows for ramp up/down of temps over long periods of time. A typical run lasts 16-20 hours depending on the parts being annealed. What is going to be the best way to measure/meter/calculate the total watts consumed for cost estimating purposes?

I need to gather more info, such as total element watts. A simple formula such as, oh say 1000 watts x 16 hours won't work well since I won't know what element zones are on/off during the cycle. The control decides how much juice based on the heat treat recipe. Mmmmmm, juicy heat treats. AAaaggggggaa.....(drool)

This is a brand new Honeywell control, so now I'm wondering if it can give me some usefull zone info...

What about a stand alone electric meter? That's probably the only real way to track it....

Emon is one company that makes sub meters. My limited experience with them tells me they're pretty decent. Just finding out how many kWh the oven uses will be good. But it might not be as simple as that. If your existing service is on a demand rate, the addition of this load *could* cost you more than you anticipate.

Let's say the oven draws oh, 20 kW, for 10 hours. That's 200 kWh of energy you'll be billed for. But if the oven is on during the "wrong" time of day, and you are on a demand rate, you could be adding to your peak. So the POCO would charge for, let's say, 120 kW @ $10 each instead of 100 kW. Maybe your existing service is not on a demand rate so none of this applies. But if it is, be aware it could have some unanticipated $$ impact.