Re: Potential Transformers

["Tesla list" <tesla@xxxxxxxxxx>]

Original poster: "Jim Lux" <jimlux@xxxxxxxxxxxxx>

>  >
>  > The two I could get at had mfg. plate info: GE Potential Transformer,
Type
>  > JVW-5, 60:1, Primary 7200kV, Imp. Level 110kV
That's a standard potential transformer, 60:1 turns ratio (i.e. it's 120V on
the meter/low voltage winding, to correspond to standard meter movements).
It's probably 7200V, not 7200kV (which would be 7.2 megavolts). A great
source for a TC, since you can easily run it at 10kVA.  (the JVW-5 implies
5kVA)

Impulse level 110kV means it will tolerate a voltage on the HV winding,
relative to ground, of 110kV without failure.

These things are used to measure the voltage of 7200V power lines, and to
supply 120V power to operate relays, etc.


 FW
>  >                                                              GE
Potential
>  > Transformer, Type JKW-5 current transformer, 25:5, Imp. Level 110 kV

That's a current transformer.  It is designed to measure 25A full scale
(driving a 5A full scale meter, which is the standard) on a HV line (also
the 7200V wire).  It too has 110kV isolation between HV windings and the
measurement winding.

If you decide to use it, make sure you NEVER run it with the meter winding
(the 5A winding) open circuited.  You get really high voltages from core
saturation which might damage the insulation.  In practice, the meter has a
very low impedance (<1 ohm), and when you remove the meter, you short the
current winding first.



>  > Any ideas what these are?
>  >
>  > And, does anyone know the status of Dr. R. ?
>  >
>  > Thanks,
>  >
>  >
>  > Tim Flood
>  >
>  >
>  >
>  >
>  >
>  >
>
>