Rtd Pt100 Xlr connector question

[vincee]

Hello all,
I'm planning to cut approximately 30cm at the end spade connector side and use from pid to chassis xlr connector. Rest of cable going to kettle to control panel (chassis xlr). Does it work? Any problem due to cutting cable? And which color should go to which pin(1, 2, 3)?

Thank you very much.

 

[Smellyglove]

Hello all,
I'm planning to cut approximately 30cm at the end spade connector side and use from pid to chassis xlr connector. Rest of cable going to kettle to control panel (chassis xlr). Does it work? Any problem due to cutting cable? And which color should go to which pin(1, 2, 3)?

Thank you very much.

View attachment 638440

I didn't understand, I'm one of those who need a helmet. You want to cut the signal cord, add XLR to both ends and then connect them together?

 

[sicktght311]

If you're just taking those 3 leads at the end, and connecting it to an XLR, it doesnt matter which pin on the XLR they go to so long as it matches on the other end at the panel. IE if you use the top pin for red, and the left and right pins for blue, then just make sure that at your panel the correct pins match up to the wiring at your PID

 

[vincee]

maybe more clear with this picture.

 

[sicktght311]

Got it. Its easy enough then. Cut the wire, wire up both sides. Make sure you put red in the same place, across the board, and then when you wire up at the pid side, if you see its not getting a signal, just swap the blue wires and you should be good to go. Red is primarily the signal, and blue is used to measure resistance i believe

 

[augiedoggy]

Ditto^^ When your done you can pat yourself on the back because you now know have to make $45 auber rtds yourself out of the $8 rtds and 99 cent xlr connectors...

On a serious note, cutting the cable wont effect the temp reading once everything is soldered together. rtds are not like theromcouples. just rememebr to pay attention to what wire goes where for when those poorly made stainless braided lines likely short out and you have to make another rtd cable.
I strongly suggest buting some telfon cable for this and you wont have to replace it again.
the wire in those stainless braided cables are smaller than human hair. Ive gone through many before switching to the telfon.

 

[sicktght311]

Also make sure the braided sheathing isnt touching your kettles or your brew table, or anything else grounded by your system. I found out that was causing my Pid temperature readings to jump around as it was providing a signal feedback loop. i've been meaning to pick up some braided fabric sheath to put over the cables just incase, but in the meantime i just make sure its tucked away and not touching anything thats grounded

 

[chrilr]

Also make sure the braided sheathing isnt touching your kettles or your brew table, or anything else grounded by your system. I found out that was causing my Pid temperature readings to jump around as it was providing a signal feedback loop. i've been meaning to pick up some braided fabric sheath to put over the cables just incase, but in the meantime i just make sure its tucked away and not touching anything thats grounded

Good to know. I have been having this issue with one of my pid's and couldn't find the problem.

 

[augiedoggy]

Good to know. I have been having this issue with one of my pid's and couldn't find the problem.

I have also had this issue on both my home system and the system at my brewpub, the rtds should only be grounded at one end since the heating element also carries a ground this causes an unbalanced ground loop... same thing that gives you that alternator whine on a car stereo or amp install if grounded at multiple points.

 

[roozter]

I am also having issues with my RTD PT100. The temp probe has been acting up. It is consistently 20 degrees Fahrenheit too hot. I have tried calibrating in an ice bath and that has lead to being as much as 100 degrees off but only sometimes. I used an ohm meter to measure at the probe connection itself and the resistance seems as expected. Is my cable bad? Any suggestions on what to do to fix this? I have tried opening up the 3 pin connectors at each end of the wire but I can't get the tiny screws for the strain relief loose. I'm also not sure what to look for if I did get them open. I have an electric heater element in my kettle that is grounded with the hot pod enclosure. I have my kettle on a stainless cart as well. I am wondering if I am having some kind of ground loop issue, or could the cable touching a hot kettle cause problems? On my last brew session I re-routed the cable to go below the stainless table top. I don't know if any part of the cable was still touching the metal on the cart but at least I had a fairly consistent 20 degrees too hot. I do have the very small / thin braided cable. oh and my probe is in a 1.5 TC connection and therefore the probe itself is also connected to all the metal from my TC fittings to my kettle.

I don't want to buy another probe, if I just need a new cable. I don't see any obvious kinks in the cable. Just hoping for some help. Thank you.

 

[sicktght311]

I am also having issues with my RTD PT100. The temp probe has been acting up. It is consistently 20 degrees Fahrenheit too hot. I have tried calibrating in an ice bath and that has lead to being as much as 100 degrees off but only sometimes. I used an ohm meter to measure at the probe connection itself and the resistance seems as expected. Is my cable bad? Any suggestions on what to do to fix this? I have tried opening up the 3 pin connectors at each end of the wire but I can't get the tiny screws for the strain relief loose. I'm also not sure what to look for if I did get them open. I have an electric heater element in my kettle that is grounded with the hot pod enclosure. I have my kettle on a stainless cart as well. I am wondering if I am having some kind of ground loop issue, or could the cable touching a hot kettle cause problems? On my last brew session I re-routed the cable to go below the stainless table top. I don't know if any part of the cable was still touching the metal on the cart but at least I had a fairly consistent 20 degrees too hot. I do have the very small / thin braided cable. oh and my probe is in a 1.5 TC connection and therefore the probe itself is also connected to all the metal from my TC fittings to my kettle.

I don't want to buy another probe, if I just need a new cable. I don't see any obvious kinks in the cable. Just hoping for some help. Thank you.

With the cost of probes and cables, why not replace to isolate the problem. Sounds like it could equally be a faulty probe as much as it could be faulty cable.

 

[stevehaun]

I use thermocouples but I am curious as to how you ground the rtd on one end? Wouldn't the rtd be grounded via the pot as well? How are you grounding the rtd?

 

[sicktght311]

I use thermocouples but I am curious as to how you ground the rtd on one end? Wouldn't the rtd be grounded via the pot as well? How are you grounding the rtd?

RTD Probes dont need to be grounded. They dont carry any voltage. Its just resistance signal

 

[augiedoggy]

I use thermocouples but I am curious as to how you ground the rtd on one end? Wouldn't the rtd be grounded via the pot as well? How are you grounding the rtd?

the pot should already be grounded via the element ground... its when you have multiple grounds of varying resistance that a ground loop comes into play. in all the cases I seen though the probe was not consistently 20 degrees off... sound almost like an incorrect pid setting.
when I had ground loop issue the temp readout would jump around as the element was turned on and off to maintain a temp.