I
NTRODUCTION
S
YSTEM
OVERVIEW
12
AlphaXpress 8731 Sign Installation and Maintenance Manual (pn 1508610601 rev. A)
Electrical distribution (DC)
Attached to the back panels in the sign housings are the power supply boxes containing one +12VDC
switching power supplies. The electronic power supplies convert the 120VAC to the required DC voltage to
power all of the electronics in the sign. DC power to the electronics is redundant and has a primary and
secondary source of DC power. Therefore, failure of a power supply will not impact sign performance. The
controller monitors the status of the power supplies.
See the “Appendix” on page 51 for power panel locations on sign configurations other than three row models.
Figure 8.
Model AX-8731-27x54-18A
All power supply panels are located in the second (center) row on three row AlphaXpress 8731 sign
configurations. Refer to Figure 2 – Figure 6 for power supply panel locations.
WARNING!
Hazardous voltage. Multiple power sources may be present. Risk of electrical shock.
Disconnect all power sources before servicing.
Sign model number
Number of power supply panels
AX-8731-27X54-18A
2
AX-8731-27X72-18A
4
AX-8731-27X90-18A
4
AX-8731-27X108-18A
4
AX-8731-27X126-18A
6
Power supplies
Breakers
Input AC
terminal
block
See the “Electrical installation” on page 15
for detailed information on AC wiring.