Motor Installations and Safety

What does DOL stand for in motor installations?

• Direct On-Line
• Direct Off-Line
• Delay On-Line
• Delay Off-Line

What is an inrush current?

• Current during normal operation
• Current when motor stops
• Initial surge of current when motor starts
• Steady state current

Which soft-start method uses resistors in series?

• Star-delta switching
• Electronic soft-start
• Resistors in series
• Part windings

What is the benefit of using a soft-start system?

• Increases inrush current
• Reduces inrush current
• Increases supply voltage
• Decreases supply voltage

Which safety standard applies to motor installations?

• VDE 0113
• ISO 9001
• IEC 61131
• EN 60204

What must be possible according to VDE 0113?

• Increase supply voltage
• Disconnect equipment from supply
• Increase motor speed
• Directly touch conductors

What should be done with all parts of the casing?

• Painted
• Insulated
• Connected to earth
• Left exposed

Which soft-start method requires a special motor with six separate windings?

• Resistors in series
• Electronic soft-start
• Star-delta switching
• Part windings

What is a requirement for the terminals in electric motor circuits?

• They should be clearly marked
• They should use screw connections
• They should be soldered where possible
• They should be left unsecured

Which of these is a method for soft-starting a motor?

• Direct On-Line
• Inrush current
• Star-delta switching
• Load fuses