TRB140 connected to TSW200 .... and broken!

Hello, I “had” an TRB140 and suppose “still” have an TSW200 (POE).
The TSW200 (POE) was supplied with 48Vcc and the TRB140 (batch 062) with 24Vcc from industrial power supplies from MeanWell.
The Ethernet connection between them destroyed the TRB140. At least the QT24A12 Gigabit 1000 BASE-T Ethernet Transformer Module it smells like smoked. The specification from this embedded transformer its for NON POE Ethernet.
Your specification for TRB140 is that “TRB140 devices support POE from HW revision 0007” Our TRB has the revision 9.0.
On the other side (maybe I’m wrong) at any POE Port should be possible to attach a standard Ethernet device even without POE.
Would you be so kind and explain me what it’s here going on? We are very late with a project and this was the last thing we needed. Could be that the POE Port from TSW200 was also “burned” ?
Best regards


TRB140 and TSW200 have different PoE standards - Passive and Active respectively.

Since the switch has been supplied with 48V, the PoE functionality has been activated. Connecting it to the LAN port of the TRB140 - which is a Passive PoE port, will damage the device.
To prevent this from happening, the TSW200 and the TRB140 should have a different power source from different PSUs.

In your case, it seems like both devices are in the same power source which is most likely the cause of TRB140 being damaged.


Best regards,

Hi Robert, as I already wrote the TRB140 was supplied with 24V from one PSU and the TSW200 was supplied with 48V from another one PSU. So I had TWO DIFFERENT PSUs.
What should I do by now? I have no trust in TSW200 anymore because :

  1. it seems to be that the POE Ports doesn’t check what kind of equipment will be attached
  2. at least your own models should be compatible
  3. it seems to be that you dont’t respect the standards
    What should I expect regarding these components from you in this situation?
    Best regards

I checked again the TNK QT24A12 used in your TRB140 and it is specified NON POE Ethernet, and designed to meet IEEE802.3ab requirements (standard network equipment)
Any PoE switch (TSW200) that shows support for IEEE standards 802.3af (15.4W max), 802.3at (30W max), and 802.3bt (60W or 100W) is active.PoE switches that comply with the standard PoE(we also call it active PoE switch), has a detection and identification function before power supply.
It seems to be something wrong either on TSW200, or in TRB140 or in both.

Hi Robert, your answer doesn’t make any sense, because TRB140 accept max 30V and the TSW200 need 48V for activating POE as you already wrote. How could I supply them other than from two different power supplies?
On the other hand remain the behavior without respecting the standards of your own items …
Best regards

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