WS-12-250-AC EARLY BIRD SPECIAL

[ralliart12]

I was going to sell the half dozen or so engineering samples of the WS-12-250-XX but Dave decided from thermal testing in our easy bake ovens under heavy POE load at the upper most thresholds of 50C to 55C it was better to change the Poly Fuses to a different style and manufacturer so the sample units I have I can not sell, sorry.

In this case, may I know approximately when will the production units of the WS-12-250-AC be ready for ordering? End-March? End-April? End-May?

[ralliart12]

Any WISP switch can power UniFi.

For the purpose of my learning, may I know how this is determine? I've only started reading up on PoE (here, & here, & of course, wikipedia), & my understanding is that it is divided into "supplies" of 802.3af & 802.3at. & 802.3at means the device draws more power? How do I map this requirement (of the device that is being powered) into the specifications of the device powering it?

Take for example, the WS-12-250-AC can dole out the following:


I can only assume 24V means it can drive 802.3af devices & the 48VH means it can drive 802.3at devices? But I have no idea about the concepts of pins in this context. Likewise, I have no idea about the concepts of amperage (in this context), i.e. 0.75A versus 1.5A.

So when it comes to things like preventing a COLD DEAD SHORT TEST on the PoE ports (source), I really know not if I am doing it, nor how to avoid doing it. Are there any sites that clarifies more about the pins & amps thing?

Moderators, if this post is severely off-topic, please do let me know.

[lligetfa]

These switches do not do 802.3af/at sensing and negotiating. They are passive PoE, meaning you need to select the required mode. The TS8-Pro does not do 802.3af/at negotiation either. None of the Ubiquiti PoE bricks negotiate either. All Ubiquiti and many other brands support passive PoE.

The 48V mode will work on all Ubiquiti kit requiring 48V and the 48VH is for AirFiber or other brands requiring it.

[wayneorack]

802.3af & 802.3at are active POE standards. The "active" means the power is supplied only when a device requests it. 802.3af is 48VDC ~.75amps. 802.3at is 48VDC ~1.5amps.

All Ubiquiti devices are passive. "Passive" means they will never ask for power, you just have to supply it. Most Ubiquiti devices are 24VDC some are 48VDC. Some devices (AirFiber) need more power (amps) than others.

Chiris has put together a line of switches that will power it all. They do not support the "active" standards, but will still support "active" devices. The operator must understand what the power requirements are of each device and plug it into an appropriate port and configure the port correctly.

The ports designed to support low amperage (.75 amps) devices use 4 wires for data and 4 wires for power. The ports designed to support high amperage (1.5 amps ) devices (both 24 VDC and 48 VDC) use all 8 wires for power and data.

A short could be caused by faulty wiring or possibly misalignment of a plug while inserting it into the switch. Chris recommends turning off the power to a port before plugging or unplugging a device.

Hopes this helps.