G
ETTING
S
TARTED
IEC61000-3
S
OFTWARE FOR
W
INDOWS
U
SER
M
ANUAL
Page 64
VPN 98-025/7
Voltech Instruments
4.14.
P
ERFORMING A
M
ANUAL
S
WITCHING
T
EST
The 2001 Edition of IEC61000-3-3 includes an Annex B that describes the
procedure for measuring dmax caused by manual switching. This is a new
procedure introduced to apply a statistical method to the voltage changes
caused by manual switching which are subject to wide variations because
of the behaviour of mechanical switches and the random point on the
voltage cycle when the switch may operate.
To perform this measurement, 24 measurements of dmax are made each of
one-minute duration.
For each one minute period:
•
The measurement is started
•
The equipment under test is switched on soon after the measurement
is started
•
The equipment under test is switched off before the end of the 1
minute period after operating for as long as possible, but in sufficient
time for all moving parts inside the EUT to come to a standstill and
that 'any dmax mitigation devices have had time to cool to the
ambient temperature before the next measurement interval is started'.
At the end of the 24 tests, the highest and lowest values are discarded and
the arithmetical average of the remaining 22 values is compared against the
value used in the flicker meter setup.