stewartmatte Posted May 6, 2015 Share Posted May 6, 2015 Hello all. Have questions for any electricians/electrical gurus out there. Small description of my upcoming display. I have 54,000 lights (all incan.) Yes,I know LED saves power and can run more lights, but, incans are my preference and have nothing really to do with my question lol.I have 7 16pc cards that I've made custom cabinet for and mounted in garage.So first question: my brother had some extra wire that he gave me. But not really like anything I've seen. It came on a spool inside of a cardboard box for easy mounting/spooling. On the box it only says 18 GA. double shielded wire. When I spliced one end open to look it has 2 18 ga wires and then a grounding wire all wrapped in a metallic foil/shield. That's it. So, anyone have an idea what wire this is and/or would it be OK to use this bc 18 ga wire is 18 ga wire?Hopefully I can use it bc he had about 700 on the spool! Would definitely help.Second question: only bc of the wire that was given to me, I started looking at different wire size ga tables to see what the distance I could run off 18 ga safely would be,if I can even use this wire. So, amperage question. On nearly every chart/table I found, it states that I can run 18 ga wire pulling only 2 amps for 60 ft. Any more amps than that,or longer run, then need to switch to 14 ga. But I've read in some post that people are running spt 1 wire for 80,100, and even 150 ft. I'm not sure but thought I seen spt wire is 18 ga as well. I do understand that if only running say 2 led strings 100 ft would be OK bc pulling approx .3 amps. But some say they run mostly incans. I only plan on running a Max of 2 strings to any run of wire,maybe 75 ft long, so absolute most be around 1.1 amps-2 amps. So I guess the question is, how far can I run 2 amps on 18 ga,and with 16 and 14 ga. And how can one 18 ga wire say Max 2 amps, but same size spt 1 wire shows 7 amps?Thanks for any help Link to comment Share on other sites More sharing options...
George Simmons Posted May 6, 2015 Share Posted May 6, 2015 (edited) Actually, your choice of incans does indeed have a lot to do with your question, given how many strings of them you can connect before reaching even as much as 1 amp. As you correctly surmised, 18 ga is what you'll typically find in spt1. I'm no electrician, and I haven't slept in a Holiday Inn Express for almost a week, but you certainly should be able to use your inherited wire. Before completing the switch-over to LEDs I ran spt1 all over the place for incans and had some runs as long as 65'. Never had any problems, although I don't think I ever loaded more than three strings of incans (approx. 1 amp) on any single channel. The thickness of the insulation has a lot to do with how many amps the wire will safely support. Edited May 6, 2015 by George Simmons Link to comment Share on other sites More sharing options...
stewartmatte Posted May 6, 2015 Author Share Posted May 6, 2015 Thanks for the response George. And hilarious statement about holiday inn lmao. I do know my incans "relate" to my question, just meant that the type of lights didn't pertain to amps I'd be pushing thru my wire. Meaning 1 to 2 amps is the same whether led or incan. I wish I had taken a picture of the wires my brother gave me. Idk if I'm just a very careful/safety oriented/nervous person,or what, but the wires looked smaller than 18 gauge. Granted I do alot of car audio and very rarely use 18, could be that I just haven't seen 18 in awhile. But should be even better that it's double shielded internally if the insulation size/protection effects the amount of amps that can be pushed thru. Anymore insight u can think of just shoot it my way, thanks again. Link to comment Share on other sites More sharing options...
plasmadrive Posted May 6, 2015 Share Posted May 6, 2015 Stewart, do some research. Much of the shielded cable it not rated above 32 volts. Some of the jacketed stuff doesn't like water either. I would look up the wire number and find the ratings. You could be asking for issues if you have the wrong stuff. Wet 32 volt cable with 120 volts run thru it from phase angle controllers can have a very high leakage currents. Especially when the triacs turn on at every half cycle. That current rise time is VERY FAST. 1 Link to comment Share on other sites More sharing options...
Mega Arch Posted May 7, 2015 Share Posted May 7, 2015 Stewart, do some research. Much of the shielded cable it not rated above 32 volts. Some of the jacketed stuff doesn't like water either. I would look up the wire number and find the ratings. You could be asking for issues if you have the wrong stuff. Wet 32 volt cable with 120 volts run thru it from phase angle controllers can have a very high leakage currents. Especially when the triacs turn on at every half cycle. That current rise time is VERY FAST. Stewart, I agree with Craig. It is most likely a low voltage instrumentation type cable. Don't get rid of it. When you start into the world of RGB you'll find a use for it. The biggest problem I see if it is a 300 volt cable is this : You are gonna spend a fortune putting male and female ends on it. Cheapest 2 wire round connectors and plugs are generally gonna run you $3 a pair. Vampires not on sale are $1.20 a pair. Buy some SPT and vampires and get 'er done... Link to comment Share on other sites More sharing options...
stewartmatte Posted May 7, 2015 Author Share Posted May 7, 2015 Thanks for the input. I think I'll just order spt wire and try to sale this wire to someone that can use it. Hint hint lol wire for sale! Link to comment Share on other sites More sharing options...
HVACR Posted May 7, 2015 Share Posted May 7, 2015 Sounds like you have a spool of shielded thermostat wire. I would not use it for 120 volts. Also this type of wire is not made to be rolled up and unrolled every year. This might be ok for some DC led lights. This is some expensive wire. Should be able to trade it for some SPT wire pretty easy. Link to comment Share on other sites More sharing options...
stewartmatte Posted May 7, 2015 Author Share Posted May 7, 2015 I didn't know how much it was, he said paid alot but didn't specify. So on ur opinion, if anyone may want to buy/trade wire let me know. Thanks again Link to comment Share on other sites More sharing options...
Max-Paul Posted May 8, 2015 Share Posted May 8, 2015 I was thinking it might be Microphone wire. HVACR I always thought that thermostat wire like for a home heating and cooling was like 4 plus wires and no shield. would like to expand my knowledge. What kind would use wire as described. Link to comment Share on other sites More sharing options...
HVACR Posted May 8, 2015 Share Posted May 8, 2015 This wire is used on Trane communicating systems. The signals are DC pulses. Most only need 2 or 3 wires to run the system. I have needed the wire in a bar I service. There lighting and sound system caused electrical interference with the remote temperature sensors. I had to run shielded cable to block the magnetic fields from causing the interference. Some new modulating systems from Trane and Rheem are starting to use this type of format for residential systems. A 500' roll of 3 conductor shielded cable list price is $315.00. The more you know........ Link to comment Share on other sites More sharing options...
stewartmatte Posted May 8, 2015 Author Share Posted May 8, 2015 Thanks for the input on what it's really for. Wow that's expensive wire! Link to comment Share on other sites More sharing options...
Max-Paul Posted May 9, 2015 Share Posted May 9, 2015 Right, thanks HVACR for that info. So, everything is going digital. I have heard that some cars now steer by wire. Me thinks that not all new is for the better Link to comment Share on other sites More sharing options...
Recommended Posts
Create an account or sign in to comment
You need to be a member in order to leave a comment
Create an account
Sign up for a new account in our community. It's easy!
Register a new accountSign in
Already have an account? Sign in here.
Sign In Now