RTAC / Techview

[AC911]

I have been working on a Trane RTAC chller. It has constantly had communication issues with the sensors. The flat cable that connects to the sensors in the machine was butchered and corroded so we replaced the cable and all the connectors. Now I am having problems binding the sensors :censored: The only sensor that connects is the very first one in the circuit. I have verified voltage all the way thru the circuit. I can also click the all led's on button in techview and all of them light.... I am at a loss on why this is not working with just changing the wire. Any help will be greatly appreciated!!!

[jayguy]

there is something that you can try, but you are going to need to save every piece of information in TechView that you can.

load the software for a RTHD. as the software comes back up, you will have a lot of errors, who cares.

then reload the software for the RTAC. you will then need to rebind every LLID and re-enter all of the setpoints, etc.

good luck.

[R123]

You should have converted the comm buss to the new pluggable connector system.

You probably have 1 llid that's defective or a connector that is not seated correctly and pulling down the whole buss. Your going to have to isolate the llids. Start by unplugging the llids in the control panel and see if the other ones communicate. Then cut the buss at the mid point and see if the rest communicate. Keep seperating the buss until you pinpoint the bad connector or llid. Your going to have to power down the controls every time you remove some llids.

[Nuclrchiller]

Are you sure you replaced all the connectors? I once found a corroded connector hidden under a piece of insulation tape. The connector was missing one of the pieces and the tape appeared undisturbed.

[AC911]

Thanks for the replies!!! 123 to convert do you have to replace the LLiD's? Jayguy I will be there again tomorrow and give that a try... Does it matter the order of the LLID'S? That is all that has changed. NUC I verified that everything was replaced. Does anyone know the voltage on the communication?? I had the 24 volts for power and the comm was about 3.9 volts DC

[Healey Nut]

Did you use the correct tool to crimp the clamshells or just a pair of robogrips ??
Dollars to donuts you have a connector/cable thats reversed or isnt crimped correctly and everything after that point wont communicate as you have shorted the buss .
Like R123 says . dissconnect everything, check your buss thoroughly and start one by one and add devices .
LLID order doesnt matter . If you want to get rid of every clamshell connector then you would have to replace all the temp and pressure sensors but not the panel LLIDs and buy a whole pile of Phoenix cables as well .

[always looking]

I rewired a 300 ton rtac last winter with the new connectors, it worked great. Didn't have to replace any llids just had to use the right kit to make the end connection. What you should have done was to start by connecting one llid at a time with all new wiring, verifying that each llid communicating without going on. I have found more bad sections of wire than bad connectors. Good luck.

[R123]

AC911, Apply for pro membership by getting your post count up to 15 and providing your credentials to the membership committee and I will post the service bulletin in the pro chiller forum that has all the info and part numbers on the pluggable connector system. I'm not going to post it in the open forum.

[milkyway]

You should have converted the comm buss to the new pluggable connector system.

You probably have 1 llid that's defective or a connector that is not seated correctly and pulling down the whole buss. Your going to have to isolate the llids. Start by unplugging the llids in the control panel and see if the other ones communicate. Then cut the buss at the mid point and see if the rest communicate. Keep seperating the buss until you pinpoint the bad connector or llid. Your going to have to power down the controls every time you remove some llids.



Is there a SB on this?

Posted this before I read ur last post, lol

Can I get a copy plz

[AC911]

R123 I will get my post count up and definatley do that !! Thanks :grin2:

[R123]

There's a bulletin that lists all the part numbers and descriptions on the new pluggable connector system, not on troubleshooting the comm issues.

[AC911]

Healey I did not use a crimping tool... I used channel locks to close the caps. I verified that they were crimped in the correct position. Could possibly be a bad crimp though. I did check voltage at the very end on the run and it did not
Seem like it was shorted.

[AC911]

I rewired a 300 ton rtac last winter with the new connectors, it worked great. Didn't have to replace any llids just had to use the right kit to make the end connection. What you should have done was to start by connecting one llid at a time with all new wiring, verifying that each llid communicating without going on. I have found more bad sections of wire than bad connectors. Good luck.

Yea I found out about the upgraded cable after the rewire was already done.

[ryan1088]

We had a similar situation happen to us last year. Lost communication to the back 3/4 of the machine and started to run the wires down and ended up finding a nicked wire on the oil temperature sensor(best that I can remember). Fixed that and everything came back.

[AC911]

There's a bulletin that lists all the part numbers and descriptions on the new pluggable connector system, not on troubleshooting the comm issues.

R123 Could you email it to me? I will repay the favor for you if you need some info I can get!! :angel: