ANATEL A643, Operator'S Manual, Page: 145 / 222

Anatel A643a - 12 VDC Bias Output 145 of 220
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Anatel
Operator Manual
11 12 VDC Bias Output
11.1
General Information
Anatel A643a Analyzers are equipped with a connection that can supply power for such
auxiliary devices as the External DAC Modules to obtain conductivity (or resistivity) and
temperature data from Anatel A643a Analyzers: the Bias connection is used by the integral
printer on Access 643P Analyzers.
11.2
Hardware Setup
The BIAS Port furnishes 12 VDC, 1/2 Amp power from the Analyzer’s supply. The port is non-
isolated and therefore discretion should be used when attaching an external device.
CAUTION:
Always disconnect the instrument from its power source before attempting to access internal
components.
Bias connections are made to the instrument’s I/O Connector Block as follows:
1) Turn the Anatel A643a Analyzer OFF and disconnect the power cord from its source.
2) Remove the I/O Connector Block from the bottom of the Analyzer by loosening its four
screws.
3) Loosen and remove the two screws that secure the metal strain relief plate.
4) Feed the interface wiring through one of the five holes at the end of the Connector
Block cover and along the corresponding slot in the foam padding.
5) Make the necessary positive and ground connections to the Analyzer’s BIAS terminals.
6) Replace the metal strain relief plate.
7) Replace the I/O Connector Block on the bottom of the Analyzer, taking care not to pinch
any wires, and secure it by tightening the screws.
Note:
The I/O Connector Block must be reinstalled correctly to conform to emissions specifications.
8) Reconnect power and turn the Analyzer ON .