Installation Steps
61179641AL1-5C
3-9
Power Connection
The Total Access 1248 provides redundant power inputs. Two sources of
–
48 VDC must be
provided to use the redundant power feature. The power wires must be 12 to 18 AWG
stranded copper. The Total Access 1248 uses a four-point terminal block (see
accept the –48 VDC and –48 VDC RET leads.
Figure 3-5. Four-point Terminal Block
NOTE
If a non-redundant power configuration is to be implemented, use
the connections marked
–48 VDC A
and
–48 VDC A RET
.
To connect the power source, perform the following steps:
1. With the power disconnected at the source, remove approximately 1/4-inch of insulation
from the ends of both power wires.
NOTE
ADTRAN recommends an external fuse rated at 3 amps.
2. Using a small flat-head screwdriver, loosen the setscrews on the top of the terminal block.
3. Insert the bare wire into the opening on the front of the terminal block, making sure that
the wire is inserted correctly according to the labeling on the unit above the terminal
block.
4. While holding the wire in place, tighten the setscrew until the wire is secure.
5. Repeat steps
until all power leads are connected.
6. Apply power to the Total Access 1248 and test the voltage and polarity on the terminal
block using the tops of the setscrews as test points.
-48 VDC B RET
-48 VDC A RET
-48 VDC A
-48 VDC B
