Symbol for CVT

[NAZ55]

Does anyone know if there's any US standard or code that dictates what the oneline symbol for Capacitive Voltage Transformer (CVT) should be?
I have always seen one with a drain coil in it and know that drain coil should be for CCVT and not CVT.

 

[cranky108]

Typically the drain coil is used as a high frequency stop for the carrier signel injection into the bottom of the capacitor stack. The old designs only had them if you purchased the carrier package. The new designs don't follow the old standards so I can't say.
They might also use the drain coil for an impedance and phase angle correction.

 

[NAZ55]

Cranky, I understand that a drain coil in series with capacitors functions as a high pass filter for carrier frequencies, but I also understand that it's an optional accessory, which comes only if a CVT is ordered with carrier accessories, thus making it suitable for PLC communications. It's not the drain coil but an inductor that's connected somewhere in between the caps that's used for phase angle correction by cancelling the capacitive reactance.

My goal from the post is to try to find out if there is any standard that dictates the oneline symbology of a CVT. I can come up with my own for both CVT and CCVT but I want to make sure I adhere to the standards if there are ANY.