CCVT hazard concern on unused carrier accessory 2

[cuky2000]

Is there a potential hazard or performance issue for a CCVT with unused carrier accessories?
I presume that a dangerous voltage can be developed on the HF terminal and possible performance issues if this terminal is not grounded.
_{NOTE: We did specify CVT but for other reasons, the utility purchased a CCVT with carrier accessories recognizing that there is no PLC in the substation.}

 

[scottf]

The HF terminal should be grounded via a drain coil. The drain coil is an air-core inductor that provides ground reference for 60Hz, but presents a high impedance for high-frequencies in the carrier range...to limit the carrier signal loss to ground.

I think you're in the ANSI/IEEE world, in which case there likely is also a drain coil in the line tuner. There also should be a carrier ground switch provided with the CCVT. If you want, you could close this switch, which is across the drain coil and would connect the HF terminal directly to ground.

We (Ritz) typically advise utility customers to purchase all of their CCVTs with carrier accessories. It doesn't impact the price too much and there is no technical down-side to having them and not using them. The benefit is knowing that any CVT can be put in a spot where carrier is required.

Attached is a general brochure and a typical schematic is on page 3.

https://files.engineering.com/getfi...0-3522-413d-bd57-e4d3d1a59bb2&file=CVO_R1.pdf

 

[cranky108]

Scott, it is good that someone here knows something about PLC. Not that many of us use it any more (I don't in my present job).
What would be nice is if companies that sell CCVT and PT were to explain more about how to use carriers (or just more information on their web sites).

 

[scottf]

Cranky108-

The PLC application info is really more in the scope of the carrier equipment manufacturers.

While the CVT is a critical component to the system, there isn't really much to expound on from the CVT's perspective.

The attached paper is one of the better ones on PLC I have in my files.

https://files.engineering.com/getfi...ulsar_PLC_Paper_(2019_06_11_13_23_01_UTC).pdf