Megger Programma Sverker 760 - Setting the Desired Current

41
SVERKER 750/760
Programma Electric AB
ZP-CD01E R05A
6.5 Setting the
desired current
1. Connect the object being tested to a
suitable output on Sverker.
2. Use the button marked A to transfer the
ammeter test point to the selected current
output or to the external ammeter panel
input.
3. Activate ON using the start switch.
4. Adjust the current using the main knob.
The current can be read from the Sverker
display.
High currents
High currents may overheat both the object being
tested and Sverker. You can prevent overheating by
generating currents of very short duration. Short-
duration currents can be read very easily using the
ammeter’s HOLD (freeze) function.
The best way to generate short-duration currents is
to use manually-controlled (momentary) or time-
limited generation. See explanation of settings in
Chapter 5.
1. Connect the object being tested to a
suitable output.
2. Use the button marked A to transfer the
ammeter test point to the selected output.
3. Activate the HOLD (freeze) function.
4. Activate ON briefly using the start switch.
5. Read the current.
6. Repeat, starting with step 4, until the
correct current is set.
Low currents and good setting
resolution
You can obtain low currents and good setting
resolution by connecting one or more of the resis-
tors in the Sverker set of resistors in series in the
current circuit. You can also use these resistors to
create a voltage divider, thereby reducing the output
current.
Limiting resistors can also be connected into the
primary side (terminal Rx/Cx) of the output trans-
former. More-over, if you want to limit the current
without generating heat, you can connect the
Sverker capacitor (only Sverker 750), al-though this
will change the phase angle of the current.
Sometimes it is advantageous to use the 0-100 A
output when you want low currents since it has the
lowest output voltage. This low voltage will drive a
lower current than any of the other Sverker outputs
through a high-ohm load or series resistor.
Always use the ammeter input for external measure-
ment when measuring low currents since it provides
the best accuracy.