measuring - part 2

[PaulLovesJamie]

So what have I measured at the car wash? Not as much (yet) because most of it is > 15Amps...

60W rough service light bulb: $51 per year per bulb.
14W compact flourescent bulb: $11 per year per bulb.
Yes, those advertisements are right! Even if I pay $10 per CF bulb, my payback is FAST!

Coke machine: $366/year
ShurVend (refrigerated): $650/year
heat tape in trough: $43/year (it comes on only below 15 degrees)
bill changer: $11/year

No, I'm not going to turn off the bill changer to save $!
But the cost of running the Coke machine was actually higher than the commissions I got, which was part of my decision to buy a shurVend a couple years ago.
But now the cost of running the refrigeration in the ShurVend sure does have me second guessing whether it was worth it to sell pepsi/coke at all!

Yes, some of these are extrapolations - I dont actually measure for a year, I measure for +- a month and multiply it out. (I have a spreadsheet if you really want a copy - pm me.)

Now... how to measure the larger items, thats my dilemma.
I've heard that my 20 year old compressor is an energy hog, and replacing it will save me a pile of cash. Yeah? How much??? Enough to justify upgrading rather than repairing? I need to know how to measure actual usage for stuff that is > 15 amps -- any advice?

Exactly how much would upgrading my old MH bay lights to pulse start save me? I want to measure it so I know, not go by opinions.
What about upgrading half of them to flourescents? Again, I want to measure it so I know, dont want to guess.

OK, I guess thats all a lot of blah-blah-blah with one conclusion and one question:
-- If you havent switched your lighted vac domes to CF bulbs, do it today man!
-- Anybody know how I can get an accurate measurement of kwh usage for bay lights and compressors and pump motors?

 

[dclark3344]

I would think you could just use an amp probe on one leg of 3 phase and then multiply it out. I like the Fluke clamp on that you just clamp around the wire. Or you could make a pig tail for one leg of the 3 phase and plug your Kill a WAtt in between the motor starter and the lead wires. If you are not carefull with this method it could be a Kill a You. Most motor plates have the AMP draw stamped on them with the different voltages.

 

[MEP001]

The ampmeter would definitely work. You could even plug your Kill-a-Watt into the pigtail and confirm the amperage readings against its reading.

 

[PaulLovesJamie]

well, I do have a clamp meter. I did think about clamping it on to measure the amps, then wiring it in-line to measure the exact voltage, then just multiplying it out. Now, for the lighting I think that would get me close - except that they use more power when they start up, right? I do know exactly how many hours the lights are on, but not how many minutes the pump motors or compressor run.

I like the idea of wiring in the killawatt meter ... need to think about that.
I'm kinda hoping somebody knows of a meter I can actually wire in. Did think about contacting the electric co & asking them, but not sure if thats a good idea - being that Im not an electrician and all.

 

[Whale of a Wash]

I have one coke machine left at a wash with higher priced electricity and I put a timer on it, the machine is shut off from 10p-7am while we are closed. It's inside and not accessible when closed. Th visi-combos are left on at washes where the electricity is only 2.9 cents. Once the demand charges are paid the electricity is inexpensive. The newest visi-combos run on 220v and have LED lighting, so low cost to leave on.
John

 

[MEP001]

You can buy an electric meter similar to what the city uses, but I can't really imagine why you'd want to just to see what something is using in electricity. With a compressor, for example, you could measure the current draw while it's running, wire an hour meter to it and just multiply the time it runs by the amerage draw. The one thing it won't figure for you is the peak usage, but you could rough guesstimate that by seeing the peak reading and how long it lasts, time how long the compressor runs on each start and work out how many extra start-up peaks to add for a given number of hours run.

Now that I think about it, knowing what it costs to run and knowing how much more it costs for each start-up could help figure out if something like a VF drive would be worth the money spent.

 

[PaulLovesJamie]

Now that I think about it, knowing what it costs to run and knowing how much more it costs for each start-up could help figure out if something like a VF drive would be worth the money spent.

yes, thats exactly why I want to measure stuff!

 

[Bubbles Galore]

Did you get to measure anything else today? This is quite the interesting thread.

 

[PaulLovesJamie]

No, haven't measured anything else yet - the kill-a-watt is at a friends house.

Did find another meter last night though, it can measure just about anything - The Energy Detective (TED). http://www.theenergydetective.com/index.html Around $150. Found a couple reviews that look good, have to see if I can get one of these, then I can measure different lighting fixtures, compressor, pump motors, etc.