DC POE connectivity option

1. FIELD NOTICE
Connecting InfiNet Wireless units to a DC power supply
Tech support cases analysis indicates that a certain number of unit failures happen upon incorrect DC
power supply connections. This paper is aimed to provide essential guidelines on DC power supply
usage.
Using DC power supply: the correct way.
Most CPE units (such as R-5000-L, R5000-Lm, R5000-S/Sm/Smb,
R-5000-Smc) require power supply voltage of +9...+56VDC.
Top-line products including base stations and InfiLINK 2x2 PRO
units (R5000-Mmx/Mmxb, R5000-Omx) support a broader power
supply voltage range of ±43VDC ... ±56VDC.
Several IDU units are available for different conditions, including
IDU-LA-G (IDU-LA) for DC-powered installations. This power
injector supports input voltage of +12..+48 VDC and should be
properly grounded.
The correct connection scheme ensures safe and trouble-free link
operation.
Connecting -48VDC power supply
As common telecom equipment utilizes -48VDC power supply, this
voltage is readily available on most installation sites. This power
supplies can be used with IW base stations and InfiLINK 2x2 PRO units
without limitations.
However, some users believe that connecting neutral terminal of the
-48VDC power supply to the line terminal of the IDU, and line terminal
of the power supply to the neutral terminal of the IDU would reverse the
-48V voltage to +48V, which is suitable for all other IW models. While
this hypothesis is true in terms of electrical potential difference, such
connection scheme also creates a short circuit due to the fact that neutral
lines in DC-powered equipment are grounded. Once the system is
powered on, this short circuit causes rapid current growth, permanently
damaging IDU, ODU and possibly the power supply itself. Note that
using incorrect power supply voltage voids unit warranty!
NEVER ATTEMPT TO REVERSE CONNECT A -48VDC POWER SUPPLY TO
INFINET WIRELESS EQUIPMENT!
Using DC/DC voltage converter
The only possible solution for using a -48VDC power supply with IW units is to install a DC/DC
voltage converter, such as MSTronic MIT-35G or similar between the power supply and the IDU.
Ensure that the converter output matches the required power voltage parameters before powering on the
unit.