10
1.5
Fault Burn Facility (except KV5-200 mk2)
The KV5-100 mk2, KV3-250 mk2 and KV4-300 mk2, KV6-80 are provided with an internal
current limit circuit which limits the output current from the unit under short circuit conditions.
This can be used to “burn” faults.
1.5.1
Fault Burning
Fault burn is where the arc is maintained through the failed test object. The product does this
by limiting the current and preventing the unit from tripping. Fault burning should be
approached very cautiously as it can cause serious damage to the test object, and is totally
unsuitable for many test objects.
1.5.2
Burn Switch
When the “burn” switch is in the “out” position, the unit behaves normally and the output
current is not limited. Switching the “burn” switch to “in” enables the current limiting
The current is limited to the following values at maximum output voltage when the “burn” is
enabled (the burn switch is in the “in” position):
Output Voltage
Maximum current
KV5-100 mk2
5kV
90-100mA
KV4-300 mk2
4kV
280 –300mA
KV3-250 mk2
3kV
160-180mA
KV6-80
6kV
75-80mA
At lower output voltages, the burn current limit reduces in proportion to the output voltage.
When the “burn” switch is in the “out” position, the maximum current is approximately 2A for
short periods of time.
1.6
High Voltage Connection
WARNING
The equipment is supplied with crocodile clips on the output. These clips are
not insulated for high voltage use, and under no conditions must the high
voltage connection be approached or touched whilst the unit is switched on.
The test object must be earthed before making or breaking connections after
testing. A prohibition zone of at least 30mm must be maintained around the
high voltage connection (from EN50191:2000)
This equipment must be used either with an interlocked enclosure for the
object under test or in a suitable high voltage test area. Adequate safety
clearances must be maintained between the operator and all high voltage
parts at all times.
