Posted 21 Aug 2021 Hi, I have new RTD module the same specification as the old one however looking to the front face of the RTD a difference can be seen: The old module is GREEN The new module is RED Anyone can tell me what this means? Share this post Link to post Share on other sites
Posted 22 Aug 2021 52 minutes ago, DanW said: You're not color blind. But maybe the people that made them are. Share this post Link to post Share on other sites
Posted 22 Aug 2021 5 hours ago, DanW said: You're not color blind. I am not color blind . The new module I bought from the internet and never expected the color Share this post Link to post Share on other sites
Posted 22 Aug 2021 The printed info as follows: GREEN RED SLC 500 SLC 500 RTD / resistance INPUT MODULE RTD / resistance INPUT MODULE 1746-NR4 1746-NR4 SER B SER B FRN 2 FRN 2 RTD TYPE: PLATINUM, COPPER.NICKEL,NICKEL-IRON RTD TYPE: PLATINUM, COPPER.NICKEL,NICKEL-IRON RESISTANCE: 150OHM, 500 OHM, 1000 OHM, 3000 OHM RESISTANCE: 150OHM, 500 OHM, 1000 OHM, 3000 OHM WIN (21) 1P0GN2X0 Mfg: 0897 FAC. 1P WIN (21) 1P0YJ9AJ mfg: 1002 FAC. 1P OPERATING TEMPERATURE CODE T3C OPERATING TEMPERATURE CODE T3C CLASS I, GROUPS A, B, C, AND D, DIV.2 CLASS I, GROUPS A, B, C, AND D, DIV.2 Share this post Link to post Share on other sites
Posted 22 Aug 2021 As Data would say "I could be chasing an untamed ornithoid without cause." Share this post Link to post Share on other sites
Posted 23 Aug 2021 Since the GREEN Unit was manufactured in 1997 and the RED was manufactured in 2002 I'd guess that the color changed as a result of what plastic was available and had little to do with the function of the units. Share this post Link to post Share on other sites
Posted 23 Aug 2021 I looked it up real quick because your question made me curious. According to Rockwell's Knowledgebase article QA11393 (Access Level: TechConnect for some unknown reason...), the green one was used for 1746-HSCE, -HSCE2, -IO12, -NR4, -NI8, -NO8I, -NO8V, -NI16I, -NI16V modules while the red one was for 1746-IA16, -OA16, -IM16, -OAP12. The article doesn't go into any other detail about any differences between the terminal blocks. Page 171 of the user manual actually goes into a little more detail about which RTB to use for which module but, again, doesn't offer any details about the difference between them other than color. These installation instructions seem to say that the color coding is there to help you avoid accidentally connecting the wrong voltage to the module. It only asserts that you shouldn't mix-and-match when it comes to thermocouple modules. When replacing the module with a new one, I would loosen the screws that hold the terminal block to the module, leaving the wiring intact. The installation instructions (linked above) explain how to do that. Share this post Link to post Share on other sites
Posted 24 Aug 2021 On 8/23/2021 at 3:52 PM, Joe E. said: I looked it up real quick because your question made me curious. According to Rockwell's Knowledgebase article QA11393 (Access Level: TechConnect for some unknown reason...), the green one was used for 1746-HSCE, -HSCE2, -IO12, -NR4, -NI8, -NO8I, -NO8V, -NI16I, -NI16V modules while the red one was for 1746-IA16, -OA16, -IM16, -OAP12. The article doesn't go into any other detail about any differences between the terminal blocks. Page 171 of the user manual actually goes into a little more detail about which RTB to use for which module but, again, doesn't offer any details about the difference between them other than color. These installation instructions seem to say that the color coding is there to help you avoid accidentally connecting the wrong voltage to the module. It only asserts that you shouldn't mix-and-match when it comes to thermocouple modules. When replacing the module with a new one, I would loosen the screws that hold the terminal block to the module, leaving the wiring intact. The installation instructions (linked above) explain how to do that. On 8/22/2021 at 0:47 AM, Mickey said: As Data would say "I could be chasing an untamed ornithoid without cause." Thank you for your explanation. I find it useful Share this post Link to post Share on other sites