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14.3 Variable voltage sources
14.3.1 Automatic Variacs
The automated variable transformer VAR 3005 series is a standard accessory for
the Teseq NSG 3040 and NSG 3060/CDN 3061 instrumentation. In combination
with a PQT module it provides a convenient means for reducing the incoming
supply voltage by adjusting the incoming EUT supply voltage to arbitrary voltages.
The VAR 3005 comes in two different versions- as double source (VAR 3005-D16)
where two supply sources are required to test equipment with universal power
supplies and as single source (VAR 3005-S16), providing best price performance
for applications where dual source is not required (mains supply of equipment
under test is a fixed value).
The VAR 3005 option is required for power quality testing (PQT) dips and inter-
rupts and is compliant with the latest revision of IEC/EN 61000-4-11 (2004)
including the variation test. The VAR 3005 units are fully automatic controlled,
driven from your NSG 3xxx generator, using the touch screen interface SUI or
the WIN3000 software application. VAR 3005 is plug and play technology, it auto
configures and avoids the user to set voltages out of range.
To prevent incorrect testing, the phase, neutral and earth line of EUT IN power
line is observed and the 50/60 Hz frequency range will be set automatically.
This feature helps especially in case where “cycle” parameter is set in a test
procedure.
Once detected by the NSG 3xxx generator, all functions offered by the VAR
3005 are available including the possibility to switch EUT power on/off. EUT
power can be switched ON and OFF manually per switch on the front panel,
or remotely from the NSG 3xxx front panel or PC control software. EUT power
can be switched off automatically at test end per sequencing program control.
For safety reasons, EUT power will switch off automatically in case of overload.
The VAR 3005 can be connected either via a NSG 3040 with its internal coupling
device or via the NSG 3060 in combination with a CDN 3061 and the built in
power quality (PQT) module. The EUT input frequency will be detected automati-
cally for a correct synchronisation of the PQT events.
