Operator's Manual
DS7A - Constant Current Stimulator
Electrical Tests
The electrical tests may be most easily accomplished using combination test equipment such as the Rigel
277 Electrical Medical Safety Analyser.
Earth Resistance
- Accessible conductive parts are required to show a low impedance connection to
protective earth. The DS7A may be tested at currents up to 25A but the only accessible conductive parts
are the Potential Equalisation Terminal on the rear panel and the shell of the BNC connectors.
Leakage Currents
- Connect the DS7A to the test equipment according to the instructions for a Class 1
device with Type BF applied parts. The applied parts of the DS7A are the red and black output terminals on
the front panel. As they are Type BF they may be tested as one part.
Leakage current measurements should be taken with the unit switched on and the output enabled.
All of the leakage current measurements, in both normal condition and single fault condition, may be taken
with the DS7A connected as described.
Insulation Resistance
- Insulation resistance may be measured using test voltages of up to 350V.
Functional Test
Refer to section “Appendix 3 .. Operational Tests”.
CAUTION:
The DS7A can generate high output voltages; care should be taken to insulate all connections
and avoid coming into contact with the output voltages. Special care should be taken to avoid contact with
both output terminals simultaneously.
Evaluation, Documentation and Preparation for Normal Use
The test results obtained should be analysed for possible non-conformance to standards and the results
recorded in line with the policy of the responsible organisation involved. Should the records show a
deterioration in test results the frequency of testing may need to be revised.
Assuming satisfactory test completion the DS7A may be returned to normal use. Check that the supply
voltage selector and the supply fuses are correct for the intended site of operation.
Digitimer Ltd.
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Copyright © 2014
File Ref: N:\Docs\Company\Manuals\DS7A\Issue-14\DS7A-iss14.odt
Last Revised: February 1, 2017
