______________________________________________
HARRIS
888-9058-001
WARNING: Disconnect and lockout AC primary power prior to servicing
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Section 9
9
50 Volt Supply
9.1 Introduction
The RF Driver and Power Amplifier modules operate on this 50 volt power supply.
There are three versions of the power supplies for different AC line voltages.
•
736-0296-000 for 208/240 volts AC 60 Hz
•
736-0312-000 for 416/480 volts AC 60 Hz
•
736-0295-000 for 380/416 volts AC 50 Hz
The supply is rated a 300 amps maximum. The supply includes a control system that
sequences the turn-on and includes fault protection.
9.2 Theory of Operation
9.2.1 Transformer Primary
The primary of the main transformer can be connected as a DELTA or WYE load to the
AC mains. One supply in a cabinet is configured as a Delta, the other a WYE. This
shifts the apparent AC phase 30 degrees, resulting in the cabinet appearing to the AC
power line as a 12 phase load. This reduces the power line harmonic content by 50%.
The series L2 choke and capacitors are for fifth harmonic filtering, the fifth harmonic is
the most harmful to motors. The 480 volt supply includes a breaker protecting the
harmonic filter from excessive currents. Drawing 839-7911-207 is a guide for all the
primary connection combinations for various AC line voltages.
NOTE:
The breaker on the front of some supplies disconnects the harmonic filter, this does
NOT remove the powers supply from service.