bellman Posted November 7, 2005 Share Posted November 7, 2005 They were refering to the G2 and G3 panels. But as Norm also mentioned, even the technical bod from Microtech recommended against it. As for functionality, I have to admit that in some cases (very short runs) then 8 core will function, but without the screening the cable will pick up all kinds of interference from other nearby sources. Only way to make sure that it works 100% of the time every time is to use Belden Regards Bellman. Service Engineer and all round nice bloke ) The views above are mine and NOT those of my employer. Link to comment Share on other sites More sharing options...
Brian c Posted November 7, 2005 Share Posted November 7, 2005 They were refering to the G2 and G3 panels. ahh.. If you don't know......ask. Link to comment Share on other sites More sharing options...
ian.cant Posted November 7, 2005 Share Posted November 7, 2005 Ive got loads of belden on 100mtr drums, whatever genuine price you can buy it for i will sell it cheaper + postage or delivery. Currently i have around 1000 mtrs on 100 mtr drums if anyones needing any. Link to comment Share on other sites More sharing options...
norman Posted November 7, 2005 Share Posted November 7, 2005 Canty = always looking for that niche market Nothing is foolproof to a sufficiently talented fool. Link to comment Share on other sites More sharing options...
Vince8282 Posted November 8, 2005 Share Posted November 8, 2005 AArrrgggghhhhhh, ONLY USE BELDEN as I said Earlier: And as the Galaxy install manual says Lost count of the number of galaxies I have been called to because of RS485 problems. Belden is what Microtech specified. You can buy it from HERE. Regards Bellman Tee hee If it's screened and earthed at the panel(only) it will be OK the techie boys say what they're told to say and it's a good idea. If it is not screened you are asking for trouble as the next cable installed 1 day later is a mains cable running along side it. PS Don't believe everything you read you young whippersnapper Practice in the morning, practice at night. Practice in the evening, until you get it right. Only make sure you are practising in the right way at the right time for it. Link to comment Share on other sites More sharing options...
bellman Posted November 8, 2005 Share Posted November 8, 2005 Hi Vince, I'm sure you already know this, but there are many other factors to consider when sending RS485 data down cables apart from screening. Cable capacitance, current carying capacity, internal resistance, cross talk between cores and also the number of twists per inch affect data integrity. As it happens Belden 8723 was designed to carry RS485 and thats why it's recommended for use with RS485 devices like the Galaxy B) Call me picky if you will but I like things to be "just so" not "near enough". I understand your point and yes as I have said before normal cable will work to an extent, as will other types of screened cable but something will be amiss somewhere, be it capacitence or NEXT, there will always be a trade off. On the other hand, Belden works, has worked for countless years and I'm sure will continue to work in the future. Regards Bellman PS, I've not been called "young" for many years vince, you've made my night PPS, My beloved has just come in and asked me why I'm still up. I explained I was busy writing about Galaxies, RS485 and Belden. she just shook her head and went back to bed. Women for you, they just don't get the important things in life Service Engineer and all round nice bloke ) The views above are mine and NOT those of my employer. Link to comment Share on other sites More sharing options...
Vince8282 Posted November 8, 2005 Share Posted November 8, 2005 Hi Vince,I'm sure you already know this, but there are many other factors to consider when sending RS485 data down cables apart from screening. Cable capacitance, current carying capacity, internal resistance, cross talk between cores and also the number of twists per inch affect data integrity. As it happens Belden 8723 was designed to carry RS485 and thats why it's recommended for use with RS485 devices like the Galaxy B) Call me picky if you will but I like things to be "just so" not "near enough". I understand your point and yes as I have said before normal cable will work to an extent, as will other types of screened cable but something will be amiss somewhere, be it capacitence or NEXT, there will always be a trade off. On the other hand, Belden works, has worked for countless years and I'm sure will continue to work in the future. Regards Bellman Hi Bellman I've no problem with your advice, I wish everything was done to the book and I am glad to see good recomendations on this site, that's why I've stuck around. As to near enough being good enough I bet your van is a lot neater than mine, but they get us both to where we want to go. I think "something will be amiss somewhere" is a bit vague and since v1.01 I have never had a problem with using screened cable except for installers not terminating it properley and as for calling you young, well compaired to me you are Best wishes mate Vince PS, I've not been called "young" for many years vince, you've made my night How did I get inside this quote? Practice in the morning, practice at night. Practice in the evening, until you get it right. Only make sure you are practising in the right way at the right time for it. Link to comment Share on other sites More sharing options...
Guest Gti Jazz Blue Posted November 8, 2005 Share Posted November 8, 2005 Phew this is all getting a bit interesting. Allready ordered the CAT foil sheilded pair cable and it is on its way. The main run isn't long as it is a bungalow the panel will be in the loft right above where the main RKP is. I will try it and will know that if I have any RKP comms issues that the first thing to try will be the cable. One other quick question, I take it that you guys run the 12v DC from the panel to power the RKP down one of the other pairs in the cable ? , Paul P.S. There is no substitute for well earner real-world experiance and wealth of knowledge. Link to comment Share on other sites More sharing options...
Guest Posted November 8, 2005 Share Posted November 8, 2005 Yes Gti Jazz, feed the RKP power using two cores in the multi-core cable from the panel, - on some longer runs I Double up on the 0v so the 0v line uses two wires to minimise on voltage drop effects. Also no-ones mentioned it but the screen should be connected to mains earth at the panel not 0v, also the screen should be continuous throught a cable run and the shield should not connect to any other core including 0v at any point! Im sure Chris Bellman will clarify this for you. Dave. Link to comment Share on other sites More sharing options...
Guest Gti Jazz Blue Posted November 8, 2005 Share Posted November 8, 2005 Yes Gti Jazz, feed the RKP using two cores in the cable from the panel, - on some longer runs I Double up on the 0v so the 0v line uses two wires to minimise on voltage drop effects. Also no-ones mentioned it but the screen should be connected to mains earth at the panel not 0v, also the screen should be continuous throught a cable run and the shield should not connect to any other core including 0v at any point!Im sure Chris Bellman will clarify this for you. Dave. Hi Dave, Yes there is a specific ground connection in the Galaxy 16+ for the screen, found it in the installer manual. Also fine with ground only at the one end so that I don't get an Earth loop. Like the double up on the 0V will implement that, I take it no harm if I double up the +12 likewise. Paul Link to comment Share on other sites More sharing options...
Recommended Posts
Archived
This topic is now archived and is closed to further replies.