Dear All,

I would like to know whether I can use power and control cable for generator winding rtds?

Is there a special cable to be used for generator RTDs?

 

There is no special wire or cable required to connect a generator RTD to an RTD monitor or control system as there would be for example, for a thermocouple (which requires thermocouple extension wire for most applications).

Most RTDs are three- or four-wire devices operating at what are considered to be low voltage signal levels. As such, one should use copper, two- or three-conductor, twisted, shielded cabling (commonly called twisted, shield pair, or twisted, shielded triad) with the shield drain wires properly grounded to eliminate any induced electrical voltage or "noise" from nearby conductors. Belden is a manufacturer commonly specified or referred to for low voltage analog signal wiring/cabling in North America.

And, the cabling should be run independently of any high voltage (110 VAC, 125 VDC or higher), high current wires and cables (in separate conduit, or wire trays/troughs).

But, standard copper conductors can be used for connecting RTDs (regardless of their location) to monitors or control systems.

 

ALan... yes! They are flat, and made of Class F or Class H insulation dimensioned to fit between stator winding for the entire slot length.

Regards,
Phil Corso

 

I agree with CSA on this, Use a three conductor triad is best but electrical control cable will do at a pinch.

I sometimes use 1-1/2 pairs of a multipair if there is one handy and you can save on conductors if the end device is a multiplexed instrument.

I wouldn't run the RTD in a cable that has AC control conductors but low voltage DC is OK. It seems a bit silly keeping the cable away from power cables when the RTD is buried in the generator winding but what can I say?

Roy