6.5 Grounding system
AGND— ground for analog inputs/outputs, internal analog/µC ground
DGND— ground for digital inputs/outputs, optically isolated
XGND— ground for external 24V aux. voltage, optically and inductively isolated
PGND— ground for encoder simulation, RS232, CAN, optically isolated
The potential isolation is shown in the block diagram (ðp.45).
6.6 Regen circuit
During braking with the aid of the motor, energy is fed back to the servo amplifier. This energy is
converted into heat in the regen resistor. The regen circuit (thresholds) are adjusted to the supply
voltage with the help of the setup software.
Our customer service can help you with the calculation of the regen power which is required. A
description of the interface can be found on page50.
Internal regen resistor
SERVOSTAR 601/603 66W
SERVOSTAR 606-620 33W
External regen resistor
SERVOSTAR 601-620 33W
Functional description
1.- Individual amplifiers,not coupled through the DC bus link (DC+, DC-)
The circuit starts to respond at a DC bus link voltage of 400V, 720V or 840V (depending on
the supply voltage).
If the energy which is fed back from the motor, as an average over time or as a peak value,
is higher than the preset regen power, then the servo amplifier will output the status “regen
power exceeded” and the regen circuit will be switched off.
At the next internal check of the DC bus link voltage (after a few ms) an overvoltage will be
detected and the servo amplifier will be switched off with the error message “Overvoltage
F02" (ðp.88).
The BTB/RTO contact (terminal X3/2,3) will be opened at the same time (ðp.68)
2.- Several servo amplifierscoupled through the DC bus link circuit (DC+, DC-)
Thanks to the built-in regen circuit, several amplifiers (even with different current ratings) can
be operated off a common DC bus link. This is achieved by an automatic adjustment of the
regen thresholds (which vary, because of tolerances). The regen energy is distributed
equally among all the amplifiers.
The combined power of all the amplifiers is always available, as continuous or peak power.
The switch-off takes place as described under 1. (above) for the servo amplifier with the
lowest switch-off threshold (resulting from tolerances). TheRTO (BTB) contact of this ampli-
fier (terminals X3/2,3) will be opened at the same time (ðp.68).
Technical Data
The technical data depend on the used servo amplifier type and on the mains voltage. See table on
the next page.
22 SERVOSTAR®601...620 Product Manual
Technical description 07/2007 Danaher Motion