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Rocket LTU power settings?

Posted: Fri Sep 11, 2020 12:10 am
by mducharme
Hello,

Our Ubiquiti Rocket LTUs that have larger numbers of customers are unstable. The LTUs are currently running on 24V. In case maybe there is not enough power, I tried the 48V setting instead but the unit did not power up, so I booted it back up again with 24V. Should I be using 48VH instead? I'm just afraid of blowing the device if it is wrong.

Thanks.

Re: Rocket LTU power settings?

Posted: Fri Sep 11, 2020 3:52 am
by mducharme
Ubiquiti has confirmed to me - at 24V, the device requires 1.5 amps with four pairs (24VH). However they could not confirm that 48VH also works. We need to power four APs on a 12 port Netonix so there are not enough 24VH ports for us. I would really appreciate if anybody knows that we can use 48VH without blowing the device. I tried 48V but it doesn't boot up at all, 0 watt draw.

Re: Rocket LTU power settings?

Posted: Fri Sep 11, 2020 9:28 am
by Dawizman
What's your cable length? I have 10 LTU AP's on a 100ft tower. I have them all running 48V without issue. They will also power on 24VH or 48VH without issue. We power all of out AF5XHD radios with 48VH which is the same thing more or less. On longer cable running you will absolutely need 4 pair power.

Re: Rocket LTU power settings?

Posted: Fri Sep 11, 2020 12:37 pm
by mducharme
Dawizman wrote:What's your cable length? I have 10 LTU AP's on a 100ft tower. I have them all running 48V without issue. They will also power on 24VH or 48VH without issue. We power all of out AF5XHD radios with 48VH which is the same thing more or less. On longer cable running you will absolutely need 4 pair power.


Hi, our cable length is 170 feet. Again, they will boot up with 24V but not with 48V. Should I be using 48VH for that length?

Re: Rocket LTU power settings?

Posted: Mon Sep 14, 2020 10:10 pm
by mducharme
We have moved them to 48VH. They boot up, and things are now working better, but unfortunately the issues we were having are not completely eliminated. Instead they seem to have simply reduced from one reboot every hour to one reboot every several hours.

Re: Rocket LTU power settings?

Posted: Wed Sep 16, 2020 3:45 pm
by mayheart
Very weird. I have about 14 LTU APs powered up with just "48v" Most are around the 70-80 days mark.

Re: Rocket LTU power settings?

Posted: Fri Sep 18, 2020 4:49 pm
by JustJoe
Beware! Gold has gotten very expensive!

Ethernet plugs & jacks are supposed to be manufactured to provide gold contact areas over a tolerance range so that different manufactures' plugs & jacks will inter-operate.

Those manufacturers are going to be constantly reducing the amount of gold they use to save money so contact resistance will go up, and on the stupidly high power requirements of LTU, the high contact resistance will reduce the current capacity. (So doubling up with 4-pair may hide the problem.)

UI experienced this a few years ago that they admitted it on their AF-5X radios, blaming it on a supplier that changed the socket spec "without telling them". So they went with a different supplier.

What's worse, knock-offs are being made on all the more reputable brand names. :(

Conclusion: Good luck !