ADTRAN 1200218L1, User Manual

Page: 32 / 122

Chapter 2. Installation and Operation
2-8 OSU 300 User Manual 61200663L1-1
The OSU 300 comes with a removable process plug that covers the
optical interface. A mechanical door engages when the fiber cable is
removed from the optical interface (see also, Figure 2-2 on page
2-4). This door protects the unit from dust in the event of the optical
interface being disconnected, and it provides additional protection
for the human eye from the laser beam.
POWERING THE UNIT
The OSU 300 can be powered from either a standard AC mains
supply or a 48 VDC Supply. When mains powered, the unit
receives power via an external power supply that converts the
mains power to a usable 48 VDC source. When powered by the AC
mains supply, the unit operates normally within specification when
supplied with AC voltages from 190–264 VAC at 47–53 Hz. The
48 VDC source interfaces to the rear panel of the unit through a
screw-down terminal block. A nylon plug allows strain relief on the
power cabling to the system.
The following requirements must be met during installation of the
DC version of the OSU 300:
1. The unit must be connected to a reliably grounded -24 or
-48 VDC source which is electrically isolated from the AC
source.
2. The branch circuit overcurrent protection should be a fuse or
circuit breaker rated 48 VDC, 15 A.
3. The unit should be installed in accordance with the
requirements of NEC NFPA 70.
4. A readily-accessible disconnect device that is suitably
approved and rated should be incorporated in the fixed wiring.
The chassis should be connected to an earth ground.