MV kwh meter 2

[GOTWW]

I need to specify - design a 4160V kwh meter onto some U.G feeders. The only accessable location is at a bank of oil switches for which all feeders enter. I am looking at installing the pt's and ct's in the hv compartment below these switches. I am looking at discrete CT's and PT's, but it is starting to become a kludged up mess.
Q. Are there small 5KV CT-VT combinations for meters that can be neatly installed?

 

[busbar]

If the 4160V system is ungrounded or high-resistance-grounded, a PT assembly like

http://www.geindustrial.com/products/specs/3pt360.pdf

may work. If the CTs are in a common location, one PT set could serve several low-burden 2-element watthour meters/transducers. It may be desirable to serve meter/transducer auxiliary power from a separate source.

 

[jbartos]

Suggestion: Visit

http://www.thomasregister.com

and type Transformers: Instrument under Product or Service, which will return 113 companies to approach to

 

[GOTWW]

One PT. YES!, that helps alot.

 

[busbar]

Understand that the link was to an open-delta PT, 4200V 3ø 3-wire to 120V 3ø 3-wire.

 

[jbartos]

Suggestion: The three-phase three-wire power supply system only requires two PTs and two CTs for the Aaron kWHr connection (or Blondels Theorem).
See Reference:
Donald G. Fink, H. Wayne Beaty "Standard Handbook for Electrical Engineers," 13th Edition, McGraw-Hill, Inc., 1993.
Page 3-29 Section 73.
When the total load is balanced, energy may be measured with one CT, and one kWHr meter (or power with one Wattmeter) using Y box, as shown in Fig. 3-28. This arrangement, which creates an artificial neutral, has two branches which have the same impedance and power factor as the kWhr meter (or wattmeter's) voltage circuit, which is third branch of the Y. Total energy (or power) is three times the reading of the kWhr meter (or Wattmeter).

 

[scottf]

Considering the price of 5 kV CTs and VTs run about $300/each, I would not think it would make sense to risk assume perfectly balanced loads in an effort to save 1 VT and 1 CT. If wrong, you could waste $600 pretty quick in lost revenue!

 

[GOTWW]

By one PT, I meant a 3-phase PT simular to the busbar PDF file link. This system is delta-wye grounded so it is low impedance grounded. I have not thought about the consequences of using a common PT in this case, however, the system supply is derived from a common main bus so I do not see a problem.

As for the CT's, are all 5KV class CT's Bar type, or do they make solid core donut types also? I have not done the thomas site because the last time I tried My computer was inadated with pop-ups, I had to reboot.