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6.
MAINTENANCE
6.1. Indication of Fault Conditions
If a fault condition appears during the operation of the amplifier, the safety circuits of OM2501A will
react immediately. There are several types of warning or fault messages that may appear on the
display when any of the protection circuits are activated. The OM2501A power amplifier provides the
following protection:
Power Out is too high
Refl. power too high
Power In is too high
Low output power (tune)
Plate current too high
Grid current is high
Screen current error
Heating voltage error
HARD FAULT
Plate voltage error
Grid voltage is low
Screen voltage error
SWR is too high
Amplifier is too hot
Most of the safety circuits are preset for two levels of activation. The first level is a warning
level. In such a case a warning message appears on the display but the power amplifier will
stay in
normal operation
. See the table above for warning and fault conditions.
When a fault condition occurs during the tuning or operation of the amplifier, the safety
circuits will
block transmitting
. The amplifier stays in
OPER
mode. After approx. 1 sec the
control circuits will automatically switch the amplifier back to the transmitting mode. If the
problem persists, the safety circuit will react again and the appropriate fault message will
appear on the PA status screen.
If the fault repeats 3 times during a 10 seconds interval, the safety circuits will turn the
amplifier to STBY mode. Cancelling a fault condition takes a short press of the
STBY/OPER button. The PA will stay in STBY mode.
NOTE:
All the warning and fault messages are stored in the onboard memory. You can display
particular warning messages and particular error messages. They are stored up to 20 at a time to the
memory. You can view them on the menu display. If the error memory is full, every new message will
delete the oldest one in the stack. It means that only the last 20 messages are visible on the display.
