Sierra Video 807121-00 - Manual (Page 4)

DigiLinx 3 RU Frame User’s Guide 4
To replace a supply to a dual supply frame, the supply assembly to be replaced is removed by unscrewing
the six black Philips screws which hold the panel to the frame. The same six screws will be used to fasten
the added power supply assembly to the frame. The new power supply assembly is connected to AC power
via a three pin male connector on the right side of the assembly. An AC power umbilical cable should be
attached to the supply assembly being removed. Remove this AC cable from the old supply assembly and
attach it to the same connector on the new power supply assembly such that the green wire of the umbilical
is adjacent to the ground symbol on the power supply. The plastic retaining clips on the power supplies AC
connector should be facing the ‘smooth’ (no holes) side of the umbilical connector. The twenty pin
umbilical cable coming from the old power supply assembly should be unplugged from the motherboard in
the frame and returned to the factory attached to the old power supply. The twenty pin umbilical cable
coming from the new power supply assembly plugs into the twenty pin connector on the motherboard of the
frame made available by the removal of the old power supply. Orient the connector to that the plastic
retaining ramps on the umbilical connector face the plastic retaining clips on the motherboard connector.
After the two connectors have been installed, the power supply module can be attached to the frame using
the six black screws removed from the blank plate. Care should be taken to avoid ‘pinching’ umbilical wires
between the power supplies front plate and the front flanges of the frame.
Power Supply Indicators
Each power supply module is equipped with a front panel featuring 3 power indication LED’s. The LED’s
indicate (from top to bottom); +5V power OK, +8V power OK, and –8V power OK. All three of these
indicators should glow green to indicate a fully functional frame. Note that these indicate the status of the
power supply they are mounted to. This means an LED may correctly indicate a failed supply without a
module malfunction because the other power supply (if purchased) is still functional .
Application Notes
Power supply replacement/installation should not be attempted while power is applied to the chassis. While
the AC harnesses are insulated, the high voltage circuitry within the power supply is not.
Cooling the frame requires an air gap to the left and right of the chassis. The air gap afforded by normal
relay rack spacing should be sufficient. Any unused module locations should be filled with blank DigiLinx
rear panels to maintain proper air resistance within the frame.