A Appendix; Abbreviations - Bosch Rexroth PSI 6500 Series Technical Information

1070087059 / 02 PSI 6500.xxx
Appendix
A Appendix
A.1

Abbreviations

AC Alternate current.
DC Direct current.
AER Assemblies under electrostatic risk.
EMC Electromagnetic compatibility.
SS Single-spot mode. For automatic devices
and manual systems.
ESD Electrostatic discharge. Abbreviation
for all terms concerning electrostatic
discharges, e.g. ESD protection, ESD
risk.
EST End slope time. Time required for the POW
to drop until completion of the 2nd CT.
ext. External. For instance, in connection with
the +24-V voltage for signal elements
(switches) and controlling elements (valves)
outside of the control unit.
SC Stepping contact. The signal is emitted af-
ter completion of the spot.
MST Main switch trigger.
PC Pulse count. Number of pulses forming the
2nd CT.
kA Kiloamperes.
Constant current regulation. Maintains the
CCR electric current in the welding circuit at a
constant level.
Constant voltage regulation. Compensates
CVR
variations in line voltage.
POW General abbreviation of power. Can refer to
SD (scale divisions) or kA.
PS Power section (thyristor or converter).
SV Solenoid valve. Activation of the cylinders,
for closing the electrodes.
SLLC System load limiting control. Monitors and
affects the load in the system.
HT Holding time. Time after the last current
time, for the weld metal to cool down.
RHT Reheating time. Also called 3rd CT.
Electric Drives
and Controls
HOT Hold-open time. Time between two spots,
in which the solenoid valve is not activated.
Only relevant in the serial-spot mode.
PE Protective earth.
PU Programming unit / welding processor.
PHA Phase angle.
PSG Transformer-rectifier unit for PSI types.
PST Pause time. Time between the current
pulses/blocks (1st, 2nd, 3rd PST).
RO Relay output.
Scale divisions. Measure for the electric
SD
phase angle.
Slope Current slope. Current rises/drops from an
initial to a final output.
SS Serial spot. Mode for manually operated
systems.
PLC Programmable logic control.
WC Weld control. Also called "Schub", "Takter"
or resistance weld control.
SST Start slope time. Time in which the POW
rises from the beginning of the 2nd CT.
Stepper Power readjustment for electrode wear
compensation.
CT Current time. There are three different cur-
rent times: 1st CT (preheating current time);
2nd CT (main welding current time); and
3rd CT (reheating current time).
All three current times can be programmed
differently with regard to time and power.
Pulses and slope can only be programmed
in the 2nd CT.
Temp. Temperature.
MC Monitoring contact. E.g. for monitoring the
pressure cylinder (which closes the elec-
trodes) or for monitoring the electrode posi-
tion (e.g. "Pressure contact").
DAT Derivative-action time. Time elapsing be-
fore the welding current time. The elec-
trodes compress the weld metal.
PHT Preheating time. Also called 1st CT.
Ign. Ignition. Enabling and disabling of the igni-
tion pulses for activation of the power sec-
tion.
Bosch Rexroth AG A-1