3
HIGH VOLTAGE SAFETY
It is essential to follow safe working procedures when working with high voltage. Information
on accepted codes of practice should be obtained from your local heath and safety regulatory
body.
IEEE standard 510-1983 (IEEE Recommended Practices for Safety in High-Voltage and High-
Power Testing) provides a working framework for establishing safe procedures, but must be
read in conjunction with local regulations and accepted codes of practice.
The following excerpts are taken from IEEE 510
•
All ungrounded terminals of the test equipment or apparatus under test should be
considered as energised.
•
Common ground connections should be solidly connected to both the test set and the test
specimen. As a minimum, the current capacity of the ground leads should exceed that
necessary to carry the maximum possible ground current. The effect of ground potential
rise due to the resistance and reactance of the earth connection should be considered.
•
Precautions should be taken to prevent accidental contact of live terminals by personnel,
either by shielding the live terminals or by providing barriers around the area.
•
The circuit should include instrumentation for indicating the test voltages.
•
Appropriate switching and, where appropriate, an observer should be provided for the
immediate de-energisation of test circuits for safety purposes. In the case of dc tests,
provisions for discharging and grounding charged terminals and supporting insulation
should also be included.
•
High-voltage and high-power tests should be performed and supervised by qualified
personnel.
•
Consideration should be given to safety regulations which may apply to specific
circumstances; for example, HSE, company, or government regulations.
In the use of signal-gathering equipment, each device should be used in such a manner that it
will not present a personnel hazard should it inadvertently become a part of the high-voltage
circuit, or fail to function properly.
