10
Rev. 1.0
2016/7/30
SS03/05/10-EC Hardware Manual
+86-400-820-9661
2.6 Connecting the Auxiliary Power Supply
If the Keep Alive function is needed, an auxiliary power supply is required.
Connect the auxiliary power supply “+” terminal to the drive terminal labeled “AUX”.
Connect the auxiliary power supply “-” terminal to the drive terminal labeled “V-”.
The SS-EC auxiliary Power Supply input accepts DC voltage range from 12 to 48VDC.
Warning: DO NOT reverse the wires
NOTE: DO NOT apply power until all connections to the drive have been made
2.7 Choosing a Power Supply
The main considerations when choosing a power supply are the voltage and current requirements of
the application.
2.7.1 Supply Voltage
The SS-EC is designed to give optimum performance at 24-48 volts DC. Choosing the voltage
depends on the performance needed and the motor/drive heating that is acceptable and/or does not
cause a drive over-temperature. Higher voltages will give higher speed performance but will cause
the SS-EC to produce higher temperatures. Using power supplies with voltage outputs that are near
the drive’s maximum may significantly reduce the operational duty-cycle.
The extended range of operation can be as low as 18VDC minimum to as high as 75VDC
maximum. When operating below 18VDC, the SS-EC may become unstable. The supply input
cannot go below 18VDC for reliable operation. If the input supply drops below 18VDC the under
voltage alarm will be triggered and the drive will stop working.
Absolute maximum power supply input is 75VDC at which point an over-voltage alarm and fault
will occur. When using a power supply that is regulated and is near the drive maximum voltage of
75VDC, a voltage clamp may be required to prevent over-voltage when regeneration occurs. When
using an unregulated power supply, make sure the no-load voltage of the supply does not exceed
the drive’s maximum input voltage of 75VDC.
2.7.2 Supply Current
The maximum supply currents required by the SS-EC are shown in the charts below at different
power supply voltage inputs. The SS-EC power supply current is lower than the winding currents
because it uses switching amplifiers to convert a high voltage and low current into lower voltage and
higher current. The more the power supply voltage exceeds the motor voltage, the less current will
be required from the power supply.
It is important to note that the current draw is significantly different at higher speeds depending on
the torque load to the motor. Estimating how much current is necessary may require a good analysis
of the load the motor will encounter.
