Help with wiring up a thermocouple and pid

[C.Edmondson]

I just got the ht forge built and it works amazing, I just ned to get this pid unit and thermocouple wired up. I dont know anything about electricity. The pid will only be use for reading the temperature, it wont control anythng, heres some pictures, it also says something in the literature about using a fuse, but what kind? I really appreciate your help,Charlie Heres some pics

 

[net_weasel]

Looks like AC power goes on terminals 9 and 10. Thermocouple goes on 4 and 5. Polarity doesn't matter on the power but it will on the thermocouple. It you happen to get it backwards the temp will decrease as the temp increases. If it does swap the leads.

 

[C.Edmondson]

Thank you so very much net weasel!!!!!!!

 

[Stacy E. Apelt - Bladesmith]

Putting a 3 amp fuse in the AC line will protect the PID from possible damage if there is a short on a periphery. Since you are only connecting the TC, it isn't really necessary, but I would put one in anyway. Get an in-line fuse holder and a 3 Amp/250V Buss fuse at Radio Shack, or a car parts place. The fuse holder goes in the hot (black) AC lead. The power and TC terminals are labeled on the PID as net weasel said.

A thermo-well or ceramic sheath for your TC is also a good idea to make it last longer.

Stacy

 

[DanGraves]

Depending on what you are using it for, Ed Caffery has a schematic on his website on how to hook up for a salt tank.

 

[C.Edmondson]

Thank you guys so much for the help, One more question, Which terminals on the thermocouple are + and - , One terminal is copper and the other is silver? Thanks again,Charlie

 

[bkshafer]

Just hook them up. If the temp reads backwards, switch the wires.

 

[SBuzek]

Usually copper is + and silver is neg.
Stan

 

[69_knives]

Thank you guys so much for the help, One more question, Which terminals on the thermocouple are + and - , One terminal is copper and the other is silver? Thanks again,Charlie

That little yellow tag on the T/C says which is which.

 

[knifemaniac]

If you use SSR - Solid state relay - here is a scetch for 220V: - two lines

And for 110V one line and zero

 

[Dr.O]

Hate to bring back a dead thread, but I have what I think is a related question.

I have the same type setup, but have not used it yet. the protective sheath for the TC is like 12 inches long, and the TC is about half that. SHould I bottom out the TC in the bottom of the sheath? Seems the wire insulation would melt off and short out if I shove it all the way inside, but if I only run the TC halfway in, the temp reading wouldn't be accurate for where the tip of the sheath is vs tip of the TC?

Did I order the wrong parts? It was directly off of the list of parts from Stacy's sticky thread from auberins.com

 

[Stacy E. Apelt - Bladesmith]

The simplest thing would be to either shorten the sheath, or get a TC with longer leads. The links I gave may have be to the general site, and not the exact size lead length. The sheath can be cut with an abrasive cut off wheel or a diamond tile saw. Might be a good idea to slip a piece of dowelling in it when cutting.

I like the TC leads to extend a few inches away from the forge lining and then use a TC terminal block to connect the thermocouple wire to them. A soft firebrick makes a perfect spacer block to do this with. The sheath and TC terminal block can be cemented into/onto the fire brick with stove cement.

CAUTION - The schematic shown is for EUROPEAN wiring. Do not hook up US 220VAC the same way.