Lost load

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john37

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Riverside, California
Can someone recommend the best way to find a lost load on a power distribution grid? I have a client who's been watching the consumption real time since November and he cannot get it to drop below 324 kwH. I am guessing there is some load that I am unaware of that is constant.

Does anyone have any recommendations on what would be the best way to find the lost load? This is a soda processing facility that does run 24/7.

Thanks.
 
That low of a load in a plant sounds like a very simple thing:

You are seeing the no-load losses from any and all stepdown transformers in the building. (commonly 480/277 to 208/120 dry types.)

Now if they throw the main and still show a load on you have a problem for sure. :grin:
 
In the months did You do a total load calc? Sounds like you have an open short... again the holidays are coming up, divide and concour! :)
 
mxslick said:
That low of a load in a plant sounds like a very simple thing:

You are seeing the no-load losses from any and all stepdown transformers in the building. (commonly 480/277 to 208/120 dry types.)

Now if they throw the main and still show a load on you have a problem for sure. :grin:
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But how is there no-load losses if the plant runs 24/7. Any plant that operates 24/7 that I know of has got to have some load other than just transformers.
 
john37 said:
Can someone recommend the best way to find a lost load on a power distribution grid? I have a client who's been watching the consumption real time since November and he cannot get it to drop below 324 kwH. I am guessing there is some load that I am unaware of that is constant.

Does anyone have any recommendations on what would be the best way to find the lost load? This is a soda processing facility that does run 24/7.

Thanks.
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If you are having a problem getting below 324kwh, it isn't because you lost a load... it is because you have too much load, more than you can account for ;)

The only way to track it down if overcurrent devices aren't tripping is to check currents at the source then wherever the supply of power branches out, accounting for the loads of each feeder, before proceeding to the next level.
 
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Being that this is a soda processing plant, would there be another way to track down the lost load than using a ammeter and taking a reading of everything in the facility? Being that the plant runs 24/7 it's not that easy to start flipping breakers throughout the whole facility to take readings.
 
john37 said:
Being that this is a soda processing plant, would there be another way to track down the lost load than using a ammeter and taking a reading of everything in the facility? Being that the plant runs 24/7 it's not that easy to start flipping breakers throughout the whole facility to take readings.
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Can you please clarify? What do you mean by 324? I was thinking the plant shut everything down and you still had 324 kW (kWh?) That would be typical for a 2-3 MW plant because of residual lighting, emergency lighting, small equipment, etc.

Is the plant down or not? If you want to track the losses down, one way or another you are going to have to start looking at the whole plant. Unless you have very detailed & updated schematics, you are not going to do this from the office.

You don't read everything (at least at first). Beginning at the source(s), start building your load map by seeing which feeders are contributing to the 324. Unless you suspect a particular machine, transformer, or process by knowledge or intuition, a load map is probably going to be your best bet.
 
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Mivey is on the right track.
The first thing to do is get the plant single line drawing and make a plan. I would study that and do some walking around before I started measuring anything.
Look for lighting, look for heaters (in switchgear), transformers that are energized but unloaded, sump pumps, coffee pots and microwaves in the security office/shack etc.
Check and clarify the data the owner gave you.
324 KW over a normal 30 day billing period is equal to one 120 volt circuit with s 3.75 amp load ( 120 volts x 3.75 amps x 1 month x 30 days/ month x24 hrs/day x 1KW/1000 VA = 324 KWH).

324 KWH is $32.40 a month at 10 cents a KWH- not much money for a shut down plant.
Going back up to a couple of paragraphs I think the first thing I would really do is get with the owner and find out what his problem really is

One other thing- if he is getting this information off his bill it may be a demand charge not an energy charge.
 
I have to gather more information from the plant manager. You all make very good points. I'll dig into this further and see what I come up with. The facility manager just sent me this information.

"I am writing in hopes that you can refer me to a consultant who will find a lost load on my power distribution grid. I have been watching my consumption real time since November and I cannot get it to drop below 324 kwH. I am guessing there is some load that I am unaware of that is constant. I don't think the office PC's would add up to this value so I am stumped.
Do you have any recommendations?"
 
100626-1322 EST

324 KWH in what time period? 1 hr, 1 day, one month. Measuring consumption in real time sounds more like a power measurement, and not an energy measurement.

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100626-1507 EST

How many sq-ft in the plant? 1000, 10,000. 100,000 or 1,000,000. A million sq-ft will usually occupy about a 1/4 sq-mile plot of land (160 acres). 10k on maybe an acre or so.

How many big motors? Any 500 HP units?

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