18
Service manual
MicroStar B
rev06
MicroStar B
09
09
09
09
09
Power supply construction
Transformer: ( T )
VDC = V2 * 1,41
Power supply
1.13
This component was designed to generate all required supply voltages in the Drive, so
only a simple single voltage power supply is needed. Use the schematic and formulas
provided below to design a supply that will be trouble-free and handle the power needed by
the drive.
NOTE:
A single ground is used in the Drive that is connected to GND, so DO NOT USE AN AUTO
TRANSFORMER.
Use a standard heavy duty power transformer without center taps on the secondary as
shown in the schematic above.
The VA rating should be 10% greater than the power needed by the system to insure cool
operation. DO NOT CONNECT ANY TRANSFORMER PRIMARY, OR SECONDARY
SIGNALS TO GROUND.
Keep the +HV GND wires, between the power supply and the drive, as short as possible.
Voltage:
The primary voltage depends on what is available locally for a single phase. The secondary
voltage is calculated from the motor’s voltage at the required operating speed.
The secondary voltage VDC is:
Example: If the secondary transformer is 44Vac, the VDC output is 44*1,41=63Vdc
The drives have to be supplied from an isolating rectified transformer secondary or a DC
isolated power supply.
