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7. Accessories
7.1. VPIS voltage presence indicating
systems
VPIS indicators are designed to indicate the presence of
service voltage.
The energized state of the unit is signalled by a light that
flashes with frequency of repetition of at least 1 Hz.
Operating temperature
The VPIS will operate reliably over a temperature range of –
25 °C to + 50 °C.
Phase comparison and testing of VPIS
Each phase of the integrated VPIS has a connection point
on the front panel, which can be used to perform phase
comparison and to test the voltage presence indicator.
Product type DXN-HXQ-01 by Fujian Nanping Anda Electrical
Manufacture Co. Ltd. is recommended for phase comparison.
Threshold values for voltage presence indication
The indication corresponding to “voltage present” appears
when the effective line-to-earth voltage is between 45% and
100% of the rated voltage. The indication corresponding to
“voltage present” does not appear when the effective line-to-
earth voltage is less than 10% of the rated voltage.
Circuit diagram
Fig. 59
– Before accessing the connections of the
indicator, make sure that the line concerned
has been put out of service and that the
cables are earthed.
– The indication provided by the device is not
sufficient to prove that the system is de-
energized.
NOTE
Under very bright lighting, it may be
necessary to improve visibility by additional
means.
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