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HARRIS
888-9058-001
WARNING: Disconnect and lockout AC primary power prior to servicing
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6.2.1 Control Interconnects
Sheet one of the drawing shows the cables that interconnect the three elements of the
control system, the main controller, the display unit assembly and the control panel unit.
This sheet also shows the UPS input power wiring and the output load distribution
terminal block TB6. The UPS AC power loads are the GUI display unit, one exciter, and
one set of logic and Accessory Tray power supplies.
The second and third sheet shows the AC and DC power distribution wiring. Sheet three
shows the AC input wiring for single and dual DC supply configurations.
6.2.2 AC Power Distribution
The top two blocks show the single AC feed and the single or dual power supplies to the
left plus the jumper wires from TB3 to TB4. The right block shows the connections for a
second AC feed and circuit breaker CB1B. There are three 1A8 units that furnish DC
samples for AC line voltage metering.
NOTE:
The 380-415 volt configuration is for 50 Hertz international transmitters. 60
Hertz 480 volt transmitters will use a 480 to 240 volt external step down
transformer. This is documented with the AC Distribution drawing in the
appropriate systems section.
TB3 and TB4 are shown again at the right edge of sheet 2 with the load wiring. For dual
power supply systems, relays K4 and K5 switch the UPS and the “back door fan” to the
backup AC feed if the main feed is not available. The phase monitor relays K1 and K3,
have closed contacts when the AC power is OK. The contacts are connected in parallel,
requiring both AC feeds to fail before the transmitter is turned off. The phase monitor
relays have adjustable drop out voltages, normally set at approximately 90% of the
supplied voltage. For example, for 208V they are set for a 185-187 volt threshold. There
is a scale on top of the monitor that can be used.
This Phase Monitor OFF state is the same as the normal transmitter OFF state. The main
contactors are open in the PA cabinets. No AC changes occur in the control cabinet. The
UPS will continue to power the GUI display unit and the main controller until the UPS
battery is discharged.
6.2.3 DC Power Supplies
The triple output supply PS1A and the optional backup supply PS1B, supply control
power plus the negative 12 volts for the Accessory Tray. The other +12 supply PS2A
and optional backup supply PS2B, furnish the positive 12 voltage requirements of the
Accessory Tray.