Electric Brewing Supply 30A BCS Giveaway!


Home Brew Forums > Home Brewing Beer > DIY Projects > RTD Sensor Wiring
Reply
 
LinkBack Thread Tools
Old 04-18-2010, 12:44 AM   #1
CorgiBrew
Feedback Score: 0 reviews
Recipes 
 
Join Date: Mar 2010
Location: Twin Cities, Land of 10k Lakes (count 'em!)
Posts: 118
Liked 2 Times on 2 Posts
Likes Given: 1

Default RTD Sensor Wiring

Okay, so I finally finished wiring my CP, fired it up and ... no explosions! But I'm getting an error from my RTD sensor (Auber PT100). Since I added a panel mount connection, I suspected an issue with my connections. Then I noticed that the two red wires at the sensor end are soldered to the same post (came this way from Auber). Is that the way they're supposed to be, or is that a wiring mistake? Can't find any wiring details on the Auber site ...

__________________
I'm sorry, Dave, I can't let you brew that.
CorgiBrew is offline
 
Reply With Quote Quick reply to this message
Old 04-18-2010, 01:32 AM   #2
jkarp
Beer Herder
HBT_SUPPORTER.png
Feedback Score: 0 reviews
 
jkarp's Avatar
Recipes 
 
Join Date: Jun 2008
Location: Elizabeth, CO
Posts: 2,105
Liked 33 Times on 29 Posts
Likes Given: 4

Default

It's best to split the reds apart and run them to their individual terminals. Otherwise, you need to run a jumper to the other red terminal.

__________________
jkarp is offline
 
Reply With Quote Quick reply to this message
Old 04-18-2010, 04:42 AM   #3
knappster
Feedback Score: 0 reviews
Recipes 
 
Join Date: Apr 2009
Location: Peoria, IL
Posts: 165
Default

Quote:
Originally Posted by CorgiBrew View Post
Okay, so I finally finished wiring my CP, fired it up and ... no explosions! But I'm getting an error from my RTD sensor (Auber PT100). Since I added a panel mount connection, I suspected an issue with my connections. Then I noticed that the two red wires at the sensor end are soldered to the same post (came this way from Auber). Is that the way they're supposed to be, or is that a wiring mistake? Can't find any wiring details on the Auber site ...
RTDs are about 100 ohms resistance so if the cable is extended, it can have a significant impact on the accuracy of the temperature. To correct for this, they often have 3 or 4 wires. With a 3-wire, you would have two wires (red in your case) connected to one lead of the RTD component and the 3rd wire (white?) connected to the other lead of the RTD component.

The actual temperature measurement will come from the resistance across one of the red wires and the white wire. The other red wire will generally need to be terminated to a separate terminal as well and this allows for a more accurate temperature because it now compensates for the resistance of the cable between the two red wires.

Hopefully this makes sense.
__________________
knappster is offline
 
Reply With Quote Quick reply to this message
Old 04-18-2010, 02:08 PM   #4
CorgiBrew
Feedback Score: 0 reviews
Recipes 
 
Join Date: Mar 2010
Location: Twin Cities, Land of 10k Lakes (count 'em!)
Posts: 118
Liked 2 Times on 2 Posts
Likes Given: 1

Default

So, from what you guys are saying, I guess that it's normal for the two red leads to start from the same pin on the sensor? Hmmm, guess there must be something else causing my PID error message. Interestingly, when I fire up the PID as configured by Auber (i.e. set up for a K-type thermocouple) I don't get an error but the temperature readout is way wrong. When I change the input setting to "21" for the PT100, that's when I get the error. Guess I'd better check that wiring again!

__________________
I'm sorry, Dave, I can't let you brew that.
CorgiBrew is offline
 
Reply With Quote Quick reply to this message
Old 04-18-2010, 02:29 PM   #5
jkarp
Beer Herder
HBT_SUPPORTER.png
Feedback Score: 0 reviews
 
jkarp's Avatar
Recipes 
 
Join Date: Jun 2008
Location: Elizabeth, CO
Posts: 2,105
Liked 33 Times on 29 Posts
Likes Given: 4

Default

Quote:
Originally Posted by CorgiBrew View Post
So, from what you guys are saying, I guess that it's normal for the two red leads to start from the same pin on the sensor? Hmmm, guess there must be something else causing my PID error message. Interestingly, when I fire up the PID as configured by Auber (i.e. set up for a K-type thermocouple) I don't get an error but the temperature readout is way wrong. When I change the input setting to "21" for the PT100, that's when I get the error. Guess I'd better check that wiring again!
That is correct. The PID is reading the resistance across the two red wires to compensate for error. That's why there's 3 total connections on the PID for an RTD.
__________________
jkarp is offline
 
Reply With Quote Quick reply to this message
Old 04-18-2010, 05:00 PM   #6
knappster
Feedback Score: 0 reviews
Recipes 
 
Join Date: Apr 2009
Location: Peoria, IL
Posts: 165
Default

Quote:
Originally Posted by CorgiBrew View Post
So, from what you guys are saying, I guess that it's normal for the two red leads to start from the same pin on the sensor? Hmmm, guess there must be something else causing my PID error message. Interestingly, when I fire up the PID as configured by Auber (i.e. set up for a K-type thermocouple) I don't get an error but the temperature readout is way wrong. When I change the input setting to "21" for the PT100, that's when I get the error. Guess I'd better check that wiring again!
What is the part # of your temperature controller? I might be able to help you with wiring if they have a manual online.

Also, a K-type thermocouple is a very different type of sensor than an RTD. Are you terminating all 3 RTD wires?
__________________
knappster is offline
 
Reply With Quote Quick reply to this message
Old 04-18-2010, 05:07 PM   #7
CorgiBrew
Feedback Score: 0 reviews
Recipes 
 
Join Date: Mar 2010
Location: Twin Cities, Land of 10k Lakes (count 'em!)
Posts: 118
Liked 2 Times on 2 Posts
Likes Given: 1

Default

Thanks knappster & jkarp. Turned out to be just a case of crossed leads. Simple as that!

__________________
I'm sorry, Dave, I can't let you brew that.
CorgiBrew is offline
 
Reply With Quote Quick reply to this message
Old 04-18-2010, 05:55 PM   #8
knappster
Feedback Score: 0 reviews
Recipes 
 
Join Date: Apr 2009
Location: Peoria, IL
Posts: 165
Default


well if something would have exploded when you powered it up, then you would have known right away!
__________________
knappster is offline
 
Reply With Quote Quick reply to this message
Old 04-18-2010, 08:58 PM   #9
CorgiBrew
Feedback Score: 0 reviews
Recipes 
 
Join Date: Mar 2010
Location: Twin Cities, Land of 10k Lakes (count 'em!)
Posts: 118
Liked 2 Times on 2 Posts
Likes Given: 1

Default

I'll say! There's nothing like the thrill of throwing that master switch for the first time. Sorta like Hurt Locker.

__________________
I'm sorry, Dave, I can't let you brew that.
CorgiBrew is offline
 
Reply With Quote Quick reply to this message
Reply



Quick Reply
Message:
Options
Thread Tools


Similar Threads
Thread Thread Starter Forum Replies Last Post
How do you mount your temp controller sensor cheesecake Bottling/Kegging 8 02-17-2010 11:04 PM
Wiring an Auber Instruments RTD sensor??? HELP Boerderij_Kabouter DIY Projects 4 02-17-2010 01:27 PM
Looking for inexpensive RTD sensor GNBrews DIY Projects 3 02-12-2010 08:00 PM
Wiimote as a level sensor P-Lay Equipment/Sanitation 0 12-18-2009 01:19 AM
freezer sensor doug1395 Bottling/Kegging 1 10-02-2009 02:40 AM