I wouldn’t look at the max rating on an RJ45 plug and decide it’s safe to run it at that voltage or current level. The contact is still a couple gold plated wires pressing against each other. Not like your typical connector with much higher contact force and area. And the plug/jack alignment and retention method is poor. And we use them in non ideal situations with cables trying to pull the plug one way or the other, vibration from wind or motors, condensation, wide temperature swings.
I also recall that currents in this range were used on telephone copper pairs to “seal” splices – break down oxidation – and when the current would punch through the oxidation, it would causes audible pops. Now, that was splices not modular plugs, I don’t know if something similar happens with an RJ connection. Gold-gold connections are also susceptible to fretting corrosion, if there is even the slightest vibration. Once that happens, I suspect the connection would build up resistance, and running a lot of current through it would cause heating and eventually cause failure. Fretting corrosion can be inhibited with a suitable contact lubricant, I don’t know if silicone grease works, I suspect not and that you would need both a lubricant and a grease to keep out moisture. From: Af [mailto:[email protected]] On Behalf Of Bill Prince Sent: Tuesday, November 15, 2016 9:14 AM To: [email protected] Subject: Re: [AFMUG] Packetflux & 450M Timing Way beyond what I would be comfortable with. bp <part15sbs{at}gmail{dot}com> On 11/15/2016 7:10 AM, Chuck McCown wrote: 300V nominally but you can get 600V cable. And since those insulation ratings are derated, pretty sure you can double them before sparks start flying. From: Bill Prince Sent: Tuesday, November 15, 2016 7:56 AM To: [email protected] <mailto:[email protected]> Subject: Re: [AFMUG] Packetflux & 450M Timing What's the breakdown voltage on the insulation for a 22 AWG wire? bp <part15sbs{at}gmail{dot}com> On 11/15/2016 6:54 AM, Chuck McCown wrote: Perhaps jack it up to 1000 volts, 12 amps... Run your whole house off of a cat 5. Now that would be an interesting youtube video. From: Bill Prince Sent: Tuesday, November 15, 2016 7:51 AM To: [email protected] <mailto:[email protected]> Subject: Re: [AFMUG] Packetflux & 450M Timing Using that kind of power scheme, and 48 volts, you're talking about over 500 watts? No way! bp <part15sbs{at}gmail{dot}com> On 11/15/2016 6:26 AM, Chuck McCown wrote: Tower ground earth ground etc, like Trango does. Yes, I do, the manufacturer of the jacks I use rates them at 1.5 amps. But you better not plug them in under load... From: Bill Prince Sent: Tuesday, November 15, 2016 7:22 AM To: [email protected] <mailto:[email protected]> Subject: Re: [AFMUG] Packetflux & 450M Timing All one polarity? Where's the drain? You really think you can get 1-1/2 amps through each of those teeny little RJ45 connections? bp <part15sbs{at}gmail{dot}com> On 11/15/2016 6:14 AM, Chuck McCown wrote: I am talking about all wires being one polarity. I think I can get 12 amps without melting anything. From: Bill Prince Sent: Monday, November 14, 2016 5:41 PM To: [email protected] <mailto:[email protected]> Subject: Re: [AFMUG] Packetflux & 450M Timing Let me be more clear. The circuit that is pins 4,5 (+), and pins 7,8 (-) is one circuit. Total of .75 amps. The circuit that is pins 1,2 (-), and pins 3,6 (+) is one circuit. Total of .75 amps. That puts 375 milliamps on each pin and each wire. That's because the power/current that is going in on pins 7 & 8, has to return on pins 4 & 5. You can't double that. Possibly more than I would be comfortable with anyway. bp <part15sbs{at}gmail{dot}com> On 11/14/2016 12:18 PM, Chuck McCown wrote: Half an amp per wire on one chart, 3.5 amps on another chart. Heating and insulation temperature rating are going to be the limiting factors there. Jacks I use have a 1.5 amp rating per pin. So, I think you can get 12 amps total if the cable is short enough. From: Bill Prince Sent: Monday, November 14, 2016 1:11 PM To: [email protected] <mailto:[email protected]> Subject: Re: [AFMUG] Packetflux & 450M Timing Each pair is one half of a power circuit. So there are 4 halves. There are two issues; how much current can each wire carry, and how much current can each connector pin can carry. bp <part15sbs{at}gmail{dot}com> On 11/14/2016 11:59 AM, Josh Luthman wrote: There are four pairs. AF5x and the H in 24vh or 48vh POE ports of Netonix do power over all four pairs. Speaking with Ubnt support last week, AF5x should ideally do four pairs when possible. 48v (0.75*4a) = 144 watts Josh Luthman Office: 937-552-2340 Direct: 937-552-2343 1100 Wayne St Suite 1337 Troy, OH 45373 On Mon, Nov 14, 2016 at 2:44 PM, Bill Prince <[email protected] <mailto:[email protected]> > wrote: At 48 volts, and .75 amps per pair of power wires, that would be 36 watts + 36 watts, or 72 watts total? Just noodling here. bp <part15sbs{at}gmail{dot}com> On 11/14/2016 11:38 AM, George Skorup wrote: For the record, http://store.packetflux.com/powerinjector-plus-sync-gigabit-version/ says: 1A per port maximum power. (48 watts at 48 Volts) So.. is the electronic over-current protection the 1A limit? Or is this just outdated info? Pretty sure it's >1A because I've "tested" it (cable leaking water into the GigE-APC, the port didn't trip, and the card was hot as hell). I was also unaware that Cambium won't be supporting sync-over-power on the 450m. I imagine the ringing/bounce issue killed that idea due to the high power consumption. On 11/14/2016 1:00 PM, Forrest Christian (List Account) wrote: The current products should power the 450M just fine. The rating is 1A per pair per port, so at the 48V you're good up to 96W. On Nov 14, 2016 7:50 PM, "George Skorup" <[email protected] <mailto:[email protected]> > wrote: The 450m pulls 70 watts. The current SyncInjector/PowerInjector+Sync is around 1A max per port. What you could do for now is a GigE-POE-APC and the new aux port version SyncBox Junior. On 11/14/2016 12:34 PM, Matt wrote: Shouldn't the sync over power for the 450M be the same as PMP450i? How is the 1u sync injector coming? On Mon, Nov 14, 2016 at 12:30 PM, Forrest Christian (List Account) <[email protected] <mailto:[email protected]> > wrote: All of the currently shipping syncbox product line are compatible. For sync over power, I have the specs, but the design isn't done yet. On Nov 14, 2016 5:40 PM, "Sam Lambie" <[email protected] <mailto:[email protected]> > wrote: A question for Forrest mostly. Have you come up with a timing product for the 450m AP yet? If not, have you got a timeline for release? Sam -- -- Sam Lambie Taosnet Wireless Tech. 575-758-7598 <tel:575-758-7598> Office www.Taosnet.com <http://www.Taosnet.com>
