My customers are expanding at a rapid pace. Most of them are in the high tech industry. They just keep adding stuff.....
The problem arrised when the POCO transformer burnt up outside due to the load increases.They were out of business for 2 days waiting fro a replacement. Downtime cost was estimated at close to a million. I posed the question to the POCO, about if they have a meter on the transformer and they monitor it for billing, why didn't they see this was going to happen? All new work must have permits and calculations, and turned in to the proper townships. They therefore know the load increases on the transformers, and the POCO can see the loads at any given time, yet the sucker burnt up. The lineman tell me, basically, one hand doesn't talk to the other when it comes to a company as big as POCO's.
So....What I want to do is monitor things myself. The POCO have plans that you can subscribe to to view usage real time via the web to monitor power consumption. But this is only at the service entrance. What I want to do is monitor all the power flow throughout the building, real time. There are numerous manufacturers of wireless sub meters out there.
So I ask you guys, anyone done this before?
There is one company featured in the ECM mag, called Electro Industries that manufacture a product called the Shark 100s. It looks good but you can't read multiple meters at one time.
Has anyone ever tryed to monitor power flow from the service entrance, to each panel of a plant before? I would like to do this to help customers realize their capabilities, and to reduce unexpected downtime. And to do cost savings calculations.
We used a company called Metersmart in Texas. I think they have since changed their name to Hunt Power or something. It was basically just what you described. We hooked it up to various feeders, wired in a phone line, they read it and post it to the web every day.
If that is not real time enough, most modern solid state meters can be purchased with any number of "add-ons". These can be KYZ pulses to whatever type of pulse counter you would want to purchase. They can be "a" or "b" contacts programmed to close whenever a pre-determined level is reached (be it KW, KVA, Kvars, whatever). Or you can spend a little more, get one with a modem and program it to dial you whenever a predetermined value is hit. The variations are endless. It largely depends on what you have available to spend.
I saw one of those home building TV shows where they had a big Solar (PV) to Utility plants. This was a test house and they had CTs hanging everywhere. They all seemerd to feed into a garden variety PC.
Re: Wireless sub-meters#59597 12/10/0509:40 AM12/10/0509:40 AM
Hi Dnk, I think that alot of utils know that they have equipment that needs swapped out but don't have the resources to do it on a PM basis. So things just blow sometimes when they aren't overloaded. Everyone's trying to cut corners these days. If you're at all like me, you've probably told folks, "Gee, I don't think we can afford to save this much money!"
We have 60+ traction power substations(I lost count). A few years ago, we installed one modem in each substation adjacent to our main metering. They are set to take many rings to answer, but when they do, the utility polls for inflow & outflow data for each line.
More recently, we started using our SCADA(Supervisory Control And Data Acquisition) system to gather our own power usage data. I had to build interfaces to adapt the common negatives of what appear to be opto-interruptor outputs with open collectors, to our SCADA +48 common scheme. Each meter puts out pulses for inflow and outflow. We need this because the utility is sending power across our tie bus that we aren't using. The SCADA RTUs have a function referred to as "Accumulators", where pulses applied to certain status inputs are counted between special polls and returned like an analog value, instead of an instantaneous "0" or "1". The MASTER end takes the data and plugs & chugs to get current hour, previous hour,day, week, month, Et,c. It's all data base manipulation at this point.
Are you just interested in monitoring or perhaps high demand load shedding? I think most folks use load shedding to avoid high demand charges or at the utility's request, rather than expecting to take out a TX if they don't. Joe
[This message has been edited by JoeTestingEngr who dangled his participle & misplaced his modifier. (edited 12-10-2005).]
[This message has been edited by JoeTestingEngr (edited 12-10-2005).]
Re: Wireless sub-meters#59598 12/10/0510:38 AM12/10/0510:38 AM
I have encountered this sort of private sub-metering a number of times.
The most common arrangement is to have a privately purchased poco-style meter installed at the switchgear, feeding a separate disconnect for each panel. This I have seen in office buildings, where the landlord does his own billing of the tenants.
Another approach, used here in several casinos, is to install an E-Mon D-Mon product at each panel. These have the advantage of your being able to place the clamps over the wires, without needing the full current to actually flow through the meter. Various models are available- whail I have not seen a "wireles read" type, I would not be at all surprised that one is offered.
Joe, Iv'e heard of folks using back-up/standby generators during peak times to reduce costs.
But I wonder how effective that is considering the cost of natural gas and diesel these days....
Funny you should mention it Dnk, because I had just such an experience at our O'Hare location. A few years ago, ComEd asked us to run on generator to lighten their load during a really hot period. We have 2, 4160V lines coming into co-located 480/277 TXs. Failure of either side will cause an undervoltage trip of that side's main, close the N.O.(non-sync feeds) bus tie, and start the 900KW Cat powered generator. The gen is the "E" feed of an ATS that has its transfer inhibited unless both mains fail. Should the second main drop, the bus tie opens, and the ATS switches to feed only the Emergency bus. There are downstream ATSs like you wouldn't believe. The problem is that the utility might take their line down for a day or more, leaving the generator running, unloaded, bringing the wetstacking issue into the mix.
My calculations showed that I could power the whole facility on the generator but the original designer interlocked things so that there was no way to close the tie while on the gen. I modified the ladder to allow feeding both busses in manual mode while on gen while still peventing the tie being closed if the non-emergency main was. I seem to recall that the gen consumes about 600 Gal/day when normally loaded.
Naturally, the engine will consume less fuel while unloaded but it is not conducive to the health of the gen. So now you have to weigh fuel costs against maintenance costs. So if you should load your generator when you test it anyway, why not just run it under load at periods of peak demand and let that be the weekly or other test???
Back to the original issue... Some of the switchgear that you deal with might already be acquiring data that is just not being harvested. Nowadays, even the cheapest or oldest computer that you throw out quite probably has a network card in it.The IQ series and similar style AC SWGR pass all kinds of data around using various network protocalls. This could be a job for last year's computer running a client/server application. A call to your friendly tech. rep. might be the first move if you're dealing with smart switchgear. Joe
Re: Wireless sub-meters#59603 12/11/0502:05 AM12/11/0502:05 AM