Reducing The Measurement Signal; Fig. 79: Adjustment Circuit Required For Secondary Circuit Currents Of >120 Ka - Bosch Rexroth PSI 6 Serie Betriebsanleitung

1070080028 / 08 | PSI 6xxx
7.2.14.1

Reducing the Measurement Signal

In the master‐slave mode, currents of up to 360 kA can be achieved in
the secondary circuit, if two slaves are used. This cannot be covered by
the voltage range available at the sensor input of the master (greatest
measurement range of the master: up to a maximum of 160 kA).
For that reason, the sensors must be adjusted if currents exceeding
120 kA are required in the secondary circuit.
X3
Toroid input 1
Toroid input
2
3
Shield
4
5
R = 1 k
i (PSI)
Fig. 79: Adjustment circuit required for secondary circuit currents
of >120 kA
Features of the adjustment circuit:
• Divides the signal range by two without changing the terminator of
the sensors
• Reduces the sensitivity of the sensors to approx. 70 mV/kA
If you use the adjustment circuit, you must
"
• deactivate the "measuring circuit test" function (the external resi­
stance in the measuring circuit is considerably increased if the ad­
justment circuit is used),
• rescale (current), because the sensitivity of the sensors is reduced
by their being connected in series.
Bosch Rexroth AG 379 / 460
Assembly
1 k
2 k
Sensors