I have a question regarding the PoE behavior of the CRS112-8P-4S-IN switch in a dual PSU setup.
**Our setup:**
We use the CRS112-8P-4S-IN with two power supplies simultaneously — a 28V PSU (included) and an additional 48-57V PSU. This allows us to power both passive PoE devices (24V) and active 802.3af/at devices (48V) on different ports at the same time.
**The problem we face:**
In this setup, some ports are configured as "forced on high" (48V) for active PoE devices. The switch applies 48V immediately without any detection or handshake.
This creates a real risk: if a low-voltage device such as MikroTik Groove (which supports only 8-30V) is accidentally connected to a port set to "forced on high", it will immediately receive 48V and may be permanently damaged — even though both are MikroTik products.
**Our question:**
What is the recommended way to handle this situation? Is there a safe configuration in RouterOS that can protect devices from receiving the wrong voltage? Or would you recommend using any external hardware solution (such as a PoE filter or adapter) between the switch port and the connected device?
We would appreciate any advice on how to best handle this in a mixed passive/active PoE environment.
We use the CRS112-8P-4S-IN switch powered by a 28V PSU, which provides passive PoE to an RB960PGS (hEX PoE) device. The RB960PGS in turn powers several GrooveA 52 access points, which are used for Wi-Fi distribution. And that equipmients doesn't work without forced on mode. We are planning to add a second PSU (48V) to the CRS112-8P-4S-IN in order to support both passive PoE (24V) and active 802.3af/at PoE (48V) devices simultaneously. In a dual PSU configuration, when a port is set to "forced on" mode in hight voltage, the switch immediately outputs 48V without any prior detection or negotiation. This poses a serious risk of damaging the RB960PGS (rated up to 30V) or the GrooveA 52 access points (rated 8–30V) if such a port is accidentally configured incorrectly or if a cable is plugged into the wrong port. We are fully aware that keeping ports in "auto" mode would eliminate this risk in our own hands. However, our network solutions are deployed for end customers who are not IT specialists and have limited knowledge of MikroTik configuration
802.3af/at we want to use maybe for camera or other type of equipments.