Input For Secondary Current Measurement (Xgm1) - Bosch Rexroth PRC 7000 Betriebsanleitung

278 / 334 Bosch Rexroth AG
Assembly
7.2.9

Input for secondary current measurement (XGM1)

Connection: to XGM1, 12-pole,
2 rows.
Mating connector is comprised in the delivery.
Cable length: max. 50 m at 0.5 mm
max. 100 m at 0.75 mm
Cable type: shielded
For the connection of a current sensor, installed in the secondary cir­
cuit.
PRC7000 units also have an integrated current sensor for the
primary circuit of the welding transformer. This gives you the possi­
bility to choose between secondary and primary measurement.
With weld times > 1 s or for temporary suppression in the event of a
sensor failure in the secondary circuit, however, you have to change
over to primary measurement.
The timers contain an integrated constant-current regulation (KSR).
Using this function, the timer controls the current flow in the secondary
circuit in such a manner that the programmed command current is ac­
tually reached.
In this way, it is possible to compensate for any process- and handling-
induced fluctuations of the secondary circuit resistance.
This regulation requires a sensor that signals the current flown in the
primary or secondary circuit of the welding transformer to the timer.
All PRC7000 units have been prepared for using the UI regulation. A
current sensor is equally required for using this functionality.
XGM1
1
Toroid input
2
Toroid input
3
Shield
4
5
Fig. 54: Connecting a KSR sensor on the secondary side
The "Measuring loop check" function is available for the automatic
check of the measuring loop.
In order to ensure the proper operation of the sensor, the following
points should be noted:
" When installing the sensor, it must be ensured that it is protected
against damages resulting from the part to be welded and from ex­
pulsion.
" The place of installation should be selected at the greatest possible
distance from current bus bars and high-current cables. This will re­
duce the noise resulting from external fields.
PRC7000 |
2
2
D
Secondary circuit
R911172834 / 02