TECHNICAL NOTE – OPERATION OF MT4000 TWTA
10/24/03
TN4000-3
MCL, INC.
27 of 46
4.4.2 Summary
Fault
All faults that are listed in the table below will cause a Summary Fault; notice the Second HPA
Switchover fault is not included in this list. While a Summary Fault condition is present, the
following will be true until a fault reset occurs:
The fault LED on the Reset button will remain illuminated.
A Summary Fault will be indicated on the User interface (J6).
A Switchover Fault will be indicated on the Switchover interface (J7).
The display will present the name of the fault on the screen (press Accept button
to clear).
The high voltage power supply will be forced off.
Auto Power will be forced off.
Standby & Transmit are disabled.
FAULTS
Tube Temp Switch
Chassis Interlock
RF Reflected
Tube Overdrive
Helix Surge
User Interlock
W.G. Arc
HV Over Volt
Filament Under Current
Tube Temp Analog
HV Primary Current
P.S. Temperature
Helix Run
W.G. Pressure
Arc Test Failed
HV Under Volt
4.4.3 Fault Reset
The Reset button is used to reset all latched faults, it is also used to clear the RF Switch Failed
alarm. Once the Reset button is pressed the following will occur:
The fault display will be cleared.
All fault statuses will be cleared
The HPA will be forced into the Standby state.
4.4.4 Fault & Alarm Trip Levels Set in Hardware
Some fault & alarm trip levels associated with an analog display are adjustable in hardware. The
table below is listing these parameters.
PARAMETER
ADJUSTMENT LOCATION
Helix Run Current fault
R123 of D161001
Helix Surge Current fault
R124 of D161001
