
BAM 1020-9800 Manual Rev W.docx
Page 60
7.4 Power Up Problems and Electrical Safety Considerations
The BAM 1020 must be at a state where it can be powered on before any other testing or
diagnosis can be performed:
•
Make sure that the BAM 1020 is plugged into the correct AC voltage. The BAM 1020 is
internally wired for either 110/120V or 220/240V. The digital, analog, and user
interface systems are powered from a universal-input power supply, so these should
work even if the line voltage is not correct. The filter tape, nozzle, and span check
control motors all run on AC voltage and will not operate correctly if the line voltage is
incorrect.
•
Check the two fuses (3.15A, 250V) inside the power switch housing. The power cord
MUST be removed before the fuse door can be opened, or you will break it. Pry open
the top edge of the power switch housing cover to access the fuses. See Section 2.6.
•
It is possible for the display contrast to be set so lightly that it looks like the display is
OFF when it is really ON. Try pressing and holding the contrast key on the front door
for a few seconds while the BAM 1020 scrolls through the contrast settings. In rare
cases the display may fail completely. If the BAM 1020
“beeps” when you press the
keys, it is ON.
•
If the above checks do not resolve the power-up problem, then there could be a failed
power supply or other significant problem inside the BAM 1020. Contact Met One for
further instructions. Do not attempt to open or repair the power supply assembly
unless qualified.
Warning! The BAM 1020 uses hazardous live voltages which can cause electrocution if
electrical safety precautions are not strictly followed during service or repair of the machine.
The BAM 1020 is designed to provide protection from hazardous voltages during normal
operation. If the equipment is modified or used in a manner not specified by the
manufacturer, protection provided by the equipment may be impaired.
Hazardous voltages are present in the following areas:
•
Power Supply AC: The main power supply is located inside the BAM 1020, inside
the power supply sub-
enclosure labeled “DANGER HIGH VOLTAGE”. The power
supply enclosure contains the main AC-to-DC converter and the motor driver board for
the transport motors, all of which contain live AC line voltage when the BAM 1020 is
powered up. Do not open the power supply sub-enclosure lid without unplugging the
BAM 1020 power cord.
•
Detector Negative High Voltage DC: The 3150 circuit board is inside the BAM
1020, mounted vertically on the outside of the power supply sub-enclosure, and
covered with a clear plastic safety shield. This circuit board generates a dangerous
negative DC bias voltage for the beta detector of between -800 and-1200 volts. Do not
remove the clear cover or touch the board without unplugging the BAM 1020. Do not
touch the large green capacitor or the detector preamp board with the BAM 1020
turned on.
•
Pump AC: The vacuum pump is powered by AC line voltage, and has its own power
cord. Do not open the electrical junction box on the side of the pump, or touch the
enclosed solid-state relay without first unplugging the pump power cord.