Fagor DDS Series Hardware Manual page 336

   Connection diagrams
10.
358
DDS
HARDWARE
Ref.1912
· 336 ·
Error Reset
When an error appears at any drive, its "Drive OK" and, therefore, the
"System OK" contact of the power supply that feeds it will be open. The relay
- KA1 will be deactivated and its associated contact open and will not be
possible to supply power to the power supply until the cause of the error is
eliminated, as long as it is a non-resettable error.
NOTE. Some of these errors (called non-resettable) may be eliminated
by applying 24 V DC to the Error Reset pin of the power supply. See
chapter 14 in the "man_dds_soft.pdf" manual for further information on
these errors.
The contact associated with the ON button resets the errors. This procedure
may close the "Drive OK" and "System OK" activating the - KA1 relay and,
while ON is still pressed, enable - KM1.
NOTE. This circuit configuration joins the error reset and the system
power-up in a single push-button.
Activating the ·System Speed Enable· of the power supply and the
·Speed Enable· of the drives
The "System Speed Enable" signal of the power supply is activated after
closing the contact KA2 with 24 V DC as a result of activating the relay -KA2.
Observe that KM1 has been closed earlier.
Now, the CNC may enable each axis (CNC Enable) and enable the "Speed
Enable" signal of each drive by means of relays - KA4, - KA5, - KA6 and - KA7.
Activating the ·Drive Enable· of the drives
Closing the contact associated with - KA2 excites the relay - KA3 with 24 V;
this relay activates the "Drive Enable" signal of all the drives.
NOTE. Observe that - KA3 is a delayed-deactivation relay where the
desired delay time t may be programmed. It may be used to keep
contactor - KM1 closed while braking a system for the necessary number
of seconds to give the power supply enough time to return the excess
energy to mains as long as the system has regenerative power supplies
and it is connected to mains (S1 closed) obviously. The delay time "t" to
program relay - KA3 must be slightly longer than the time it takes the
system to come to a full stop.
INFORMATION. In the diagrams provided later on, the green ON light
indicates that the "System Speed Enable" of the power supply is activated;
in other words, the "Speed Enable" in each drive related to it and the SPENA
i
signal of the CNC (sent to each drive via SERCOS or CAN) are activated
and there will then be motor torque (Drive Enable signal at each drive and
DRENA signal of the CNC). The red OFF light indicates that all the previous
signals are disabled.
NOTE. Remember that a drive will only respond to an external velocity
command when the Drive Enable, Speed Enable and System Speed
Enable signals (besides the DRENA and SPENA signals of the CNC) are
active (24 V DC).
A stop may be caused by:
 opening the main power switch - S1 , one or several fuses have blown
or there is simply a power outage while the system is running. The motor
brakes with emergency ramps if they were initially set by parameters.
Regardless of the power supply being used, it will not be possible to
return to mains the excess energy generated by braking (remember that
the mains connection has been opened). It causes a voltage rise at the
power bus as a result of saving that energy at the capacitors.
NOTE. Remember that the energy saved at the capacitors responds
to the formula: Energy saved = 0.5 C·V²
When exceeding a certain bus voltage (760-768 V DC) the Ballast circuit
is activated to dissipate that excess of energy in an resistor (internal or
external) and the motor performs a controlled stop (with motor torque).