CHAPTER 3
Operation
9
Warning Lamps and Fault Detection
If one of the red warning lamps lights, a fault has occurred in the system. Under such circum-
stances, the amplifier automatically stops to protect the amplifier and vibration exciter. To help
establish the cause of the shut-down, some probable faults are given in the table below.
If incorrect amplifier control settings or exciter connections cause shut-down, turn the Variable
Gain (dB) to
Reset
and make the necessary adjustments. Normal operation can then be resumed
by returning Variable Gain (dB) to the position used for test.
If a shut-down is caused by an internal fault in the amplifier or exciter, stop the test by setting
Variable Gain (dB) to
Reset
and switch the amplifier off. Then consult your Brüel & Kjær
service representative.
Warning Lamp
Probable Fault
Current
Input drive level too high for
Current Limit A (RMS)
setting
Wrong output connections to exciter
Temperature
Overdrive at low frequencies
Wrong output connections to exciter
Vibration laboratory temperature too high
Forced air cooling system of amplifier blocked
