Need some help with 4 wire vs 3 wire temp probe

[BrewinSoldier]

Hey guys! I just upgraded my electric rims system from a 240V 3500watt Blichmann Rims ricket running off the Blichmann 240V electric controller, to a 2" tri clover Rims tube with a 240V 5500w element from ebrewsupply. I tried to adapt my blichmann temperature sensor over to the new rims tube. The temp probe doesn't go into the tube far enough at all and is messing up the temp reading by like 25°. When I flipped the rims tube upside down so that the temp probe is on the bottom and the heating element on top, it started working like it should, but I don't like having it oriented like that as the temp probe should be on the "out" of the rims tube.

So I need a longer temp probe probably 4-6"(I'll measure tomorrow). Problem I'm running into is that the blichmann is a 4 pin connector on both the controller and on the temp probe. Everything I'm finding has 3 pins.

How do I get this to work? I don't won't to have to go spend a bunch more money on a new controller just to be able to use the 3 pin connector and temp probes.

Thanks for any help.

 

[Brumateur]

Disassemble an existing temperature sensor and put in a new thermowell - http://rover.ebay.com/rover/1/711-5...0001&campid=5338413729&icep_item=142876694658

 

[BeardedBrews]

The fourth wire is just a ground, a three wire probe should work just fine. You will either need to disassemble the plug on your existing cable or order a spare cable from blichmann and take that apart.

The alternative would be to open the controller and swap out the panel mounted connector with a 3-pin version to match your new longer probe.

Just keep in mind that eBrew, Blichmann, and Auber are all selling assorted versions of the same temp probes available on eBay. The quality of wires and connector in the probes vary quite a bit. I have been quite happy with this one https://rover.ebay.com/rover/0/0/0?mpre=https://www.ebay.ca/ulk/itm/232587883318

You can generally tell by the image what wiring version you're getting.

 

[augiedoggy]

The fourth wire is just a ground, a three wire probe should work just fine. You will either need to disassemble the plug on your existing cable or order a spare cable from blichmann and take that apart.

The alternative would be to open the controller and swap out the panel mounted connector with a 3-pin version to match your new longer probe.

Just keep in mind that eBrew, Blichmann, and Auber are all selling assorted versions of the same temp probes available on eBay. The quality of wires and connector in the probes vary quite a bit. I have been quite happy with this one https://rover.ebay.com/rover/0/0/0?mpre=https://www.ebay.ca/ulk/itm/232587883318

You can generally tell by the image what wiring version you're getting.

I use the same version after trying the others and found the TELFON (not teflon like I previously thought) is the best type of cable ive found thus far. the stainless braided lines are junk IMO.

 

[ajdelange]

No, the 4th wire isn't just a ground. On a 4 wire RTD each side of the resistor has two wires connected to it. The idea is that you pass the excitation current to the RTD through one set of wires and read the voltage across it with the other two thus removing the wiring voltage drop from the excitation current. Any controller/meter you buy should be configurable for 2 or 3 wire configuration. Just set the controller for the 3 wire configuration and ignore the 4th wire. It's quite likely the system is already wired for 3 wires as 4 wire configuration is pretty unusual these days except in ultra precise measurement situations. IOW two of the wires in the 4 wire hookup may already be connected together at the controller.