ISOLATE MALFUNCTIONS TO MODULE LEVEL
Section I. CIRCUIT DESCRIPTIONS
This lesson is concerned with troubleshooting the system and the assemblies in
the system and builds on the knowledge of PMCS of the CS-8952 X-ray system. Circuit
functional descriptions (CFDs) are provided where needed to show complete functional
circuits without regard to physical component placement. Circuit functional descriptions
are a bridge between board schematics and system wiring diagrams, and allow service
personnel to more clearly visualize the functions of the major circuits in the system.
POWER CIRCUIT, CIRCUIT FUNCTION DESCRIPTION 1.0
Refer to figure 2-1. The MXR-350 X-ray Generator receives its power via the
factory-supplied line cable which is connected into disconnect box "B" as follows:
L1 (blk), L2 (wht), and G (grn). The main supply necessary for safe and normal
operation of the generator must be between 190 volts and 270 volts, single phase, and
either 50Hz or 60Hz.
a. The "NO-LOAD" to "FULL-LOAD" line regulation must be less than an
eight-percent change, as measured at the main disconnect box "B."
b. In the control, L1 (blk) and L2 (wht) connect to parallel contacts, to reduce the
contact resistance of Re-20 which is the line contactor. The G (grn) conductor in the
line cable connects to a grounding stud on the control chassis.
c. At the line contactor Re-20, L1 becomes T1 and L2 becomes T2. Both T1
and T2 connect to the autotransformer through compensation switches. Lead T1
connects via line compensation, coarse, to terminals A1 through A6. T2 connects via
line compensation, fine, to terminals A14, through A20, to cover the input voltage
The transformer must be connected as close as possible to the incoming
line voltage for proper and safe operation of the X-ray system.
d. The line contactor Re-20 is initially supplied voltage via the MAIN
push-button switch and L1 and L2. A tap from L1 is fused by F1, becomes L1P, through
circuit breaker CB26. Then it becomes L1F across the MAINS push-button switch, and
becomes CL1 to one side of the coil for Re-20, through a normally closed pole of relay
Re-1 on the rotor-control board.