Pyro wires

[Nessmuk]

Got the pyro wire blues.
Yellow is hot and red is ground on my type k thermocouple. But what do I do with the copper wire in with them?

 

[THEFERMANATOR]

Is it a wire wrapped around the others? If so, it's most likely a shielding wire you connect to ground to prevent rf interference with the thermocouple since they work on such small voltage changes.

 

[Will L.]

Picture please.
Like Ferm mentioned, could be shielding. If it is, only ground 1 side of any shielding, always- regardless of voltage.

 

[Nessmuk]

That makes sense. I'll hook it to ground.

 

[guybb3]

The guys are probably right. Thermocouples only use two wires and red is always neagative. That throws people off a lot

 

[Will L.]

No, i have to kill that.

I have installed thousands of thermocouplers, and worked on many things that someone would lse installed. Red is not always negative.

Poliariry based on feed and voltage. High voltage TC use standard priportory coloring. 48v red or pink is standard hot.

No color is mandated by NEC except green- ground. And on a 2wire tc,there is no ground.

Red is most commonly (not always) negative on type k thermocouplers, but your most magnetic feed is always your negative.

 

[guybb3]

Well every single one I've ever seen had red as the negative. The OMEGA reference book agrees with this as well. We are talking about the wires and not the connectors, right?

 

[Will L.]

Yes. And everyone Omega does is red negative. Being the biggest and the best, they are setting the standard and others are starting to copy more consistently. I just wanted you and others to be aware that they may run acrosss something where it isn't. It isnt a standard unfortunately. NEC won't set colors for anything other than ground. Wish they would, and wish it applied to ase engineering too.

If ever unsure, test with a magnet.

I love omega btw. Best technical help around on control gadgets. I feel wierd, it has been almost 18 months since I called them.
1 (800) 872-9436 Engineering
1 (800) 622-2378 Tech support
1 (800) 826-6342 Sales

 

[guybb3]

I love the place too. Unfortunately for us they don't supply the type of certification we need for accepting one of their calibrations so we have to re-cal their stuff when we get it in even though it's brand new. Aggravating