Fault conditions
The lamps shall not impair safety when operated under fault conditions which may occur
during the intended use.
Each of the following fault conditions is applied in turn, as well as any other associated fault
conditions that may arise from it as logical consequences. Only one component at a time is
subjected to a fault condition.
a) In a switch-start circuit, the starter is short-circuited.
b) Short-circuit across capacitors.
c) The lamp does not start, because one of the cathodes is broken.
d) The lamp does not start, although the cathode circuits are intact (de-activated lamp).
e) The lamp operates, but one of the cathodes is de-activated or broken (rectifying effect).
f) Opening or bridging other points in the circuit where the diagram indicates that such a
fault condition may impair safety.
Examination of the lamp and its circuit diagram will generally show the fault conditions which
should be applied. These are applied in sequence in the order that is most convenient.
The manufacturer or responsible vendor shall submit a specially prepared lamp with the relevant
fault condition, where possible in such a way that by operating a switch outside the lamp
the fault condition is introduced.
Components or devices in which a short-circuit does not occur shall not be bridged. Similarly,
components or devices in which an open circuit cannot occur shall not be interrupted.
Manufacturers or responsible vendors shall produce evidence that the components behave in
a way that does not impair safety, for instance, by showing compliance with the relevant
specification.
In the case of fault conditions a), b) or f), compliance is checked by operating the sample free
burning at room temperature and at a voltage between 90 % and 110 % of the rated voltage
or, in case of a voltage range, at a voltage between 90 % and 110 % of the mean voltage of
that range until stable conditions have been reached, then introducing the fault condition.
In the case of fault conditions c), d) or e), the same operating conditions apply but the fault
condition is introduced at the start of the test.
The sample is then tested a further 8 h. During this test it shall not catch fire, or produce
flammable gases and live parts shall not become accessible.
To check if gases liberated from component parts are flammable or not, a test with a highfrequency
spark generator is made.
To check if accessible parts have become live, a test in accordance with clause 6 is made.
The insulation resistance (see 7.1) is checked with a d.c. voltage of approximately 1 000 V.
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