Haklir,
That is a very odd way of calculating a demand charge! Is this a U.S. utility? If so, I would ask to see a copy of their rate structure.
Greg May
Two Sockets - Two Meters, Inc.
WEB: www.socket-two-me.com
GOTWW,
You should also check out the Turtle system by a company called Hunt Technologies. Their WEB site is: http://www.turtletech.com/AboutUs.aspx
As the name implies, this ultra narrow band power line carrier system sends meter readings and other information very s l o w l y.
A new version...
Scott,
These were Schlumberger outdoor CTs mounted in a ground line cabinet. There were "in and out" elbows for underground primary (13,800/7970 Y) on one side that were placed backwards, causing the watthour meter to reverse. The socket was then rewired, creating an inadvertent lagging "Q"...
Scott,
Very interesting. As you may know, I was almost killed as the result of an electrostatic voltage buildup on a medium voltage CT. I was very careful to close the shorting link on the CT, but neglected to maintain a secondary ground reference. When attempting to rewire the secondary...
Scott,
Just to clarify, the peak voltage that you are referring to has nothing to do with any electro-static voltage buildup that would be present as the result of an absence of a secondary ground reference. This electro-static voltage buildup could also be of significant magnitude.
Greg May...
Breaker,
I would just like to add a small comment to the previous excellent posting. DO NOT attempt to measure the secondary voltage of an open circuit CT with a standard voltmeter! As the previous posting indicated, the voltage waveform is highly spiked and will probably have a significantly...
jbartos,
You are correct. Unfortunately, several of the higher voltage installations that I have seen have the concentric neutral passing through the window of the 600 volt CT in only one direction. Apparently some forget that it (concentric neutral) can, and many times does, carry current...
Comment on the previous comments: If the insulated conductor has a concentric neutral (shield) that is referenced at both ends, the shield MUST be routed back through the window of the CT to cancel any neutral or stray currents that may exist in the shield.
Greg May
Two Sockets - Two Meters...
Stevenal,
You have described a worst case scenario for PF penalty billing. A very poor load factor combined with an average PF calculated from Kwh and KVarh is very unfair (in this case)and has little relationship to what it costs the utility to serve this load.
Rather than investigating...
electronclem,
25-35 years ago 480/277 volt, 4-wire wye was rare in U.S. small commercial applications. That is not at all true today. Even rather small strip malls and convenience stores are going to the higher voltages as the loads are predominately lighting, air conditioning, and...
nostrayvoltage,
If you are a standup type guy, I offer my apologies. Unfortunately, from my experience, most of the people making claims against utilties in the stray voltage area make used car salesmen look like saints.
If you could kindly explain how dairy cows know when to complain about...
Stray voltage may not yet be in the same league with PCBs or cold fusion, but it is close. Personally, I would prefer that independent electrical consultants and engineers engage in honest and useful work.
I have always found it curious that milk cows know to complain about stray voltage when the price of milk is low. Amazing!
One of the many problems I have with the whole stray voltage issue is the automatic assumption that the electric utility is responsible, even when the source of the...
scott,
I totally agree with you. This point, along with the differences between accuracy burden rating and thermal burden rating are not well understood by many people.
One of the problems with the 25%-100% burden rating is that the burden imposed by the non-power supply phases of solid state...
Scott,
Also not wanting to be a pest, but your 10 VA for a typical solid state meter power supply is way out of line. It is important to remember that the VA burden imposed by a wide voltage range power supply goes up virtually exponentially once you exceed ~300 volts. In the 120 volt range...
rbulsara,
I must disgree with your assertion that an ungrounded or corner ground delta system is all that is available. Have you thought about grounding a center tap of one of the transformers, creating 480/240 volt 4-wire delta? Many people prefer this to either an ungrounded system or a...
joozu6,
I agree with you. A 480 Volt pad mount transformer is now considered obsolete in much of the U.S. and has been replaced with 480/277 volt grounded wye type.
Some have been tempted to leave the grounded wye phase back at the transformer and supply to the customer only the three hot...
jbartos,
You are correct in that old induction meters and relays were generally calibrated at 115 or 120 volts. Therefore, the objective was to use a VT that would result in as close to the calibration voltage as was practical to achieve the best accuracy. For 480/277 volt applications, some...
