Chapter 5 Main Circuit TerminalsMS300 (High Speed Model) 
 
5-2
DANGER
 
  Fasten the main circuit terminal screws to prevent sparking by loose screws 
due to vibration. 
  When needed, only use an inductive filter at the motor output terminals 
U/T1, V/T2, W/T3 of the AC motor drive. DO NOT use phase-compensation 
capacitors or L-C (Inductance-Capacitance) or R-C 
(Resistance-Capacitance), unless approved by Delta. 
  DO NOT connect brake resistor directly to +1/DC+ to DC-, +2/B1 to DC- to 
prevent damage to the drive.
 
  Ensure proper insulation of main circuit wiring in accordance with the 
relevant safety regulations.
 
 
Main power terminals 
  R/L1, S/L2 and T/L3 have no phase-sequence requirement; they can be 
connected in any sequence. 
  It is recommended adding a magnetic contactor (MC) at the power input to 
cut off power quickly and reduce malfunctioning when the protection 
function of the AC motor drive is activated. Both ends of the MC should have 
an R-C surge absorber. 
  Please ensure voltages and currents are within specification. 
  When using a general GFCI (Ground Fault Circuit Interrupter), select a 
sensitivity ≥ 200 mA and ≥ 0.1 s operation time to avoid nuisance tripping. 
  Please use conduits or shielded cables for the power wiring and ground 
both ends of the conduit or shielded cables. 
  DO NOT run/stop the drive by turning the power ON/OFF. Run/stop the 
drive by RUN/STOP command. If you still need to run/stop the drive by 
turning power ON/OFF, it is strongly recommended to do so only ONCE per 
hour. 
  To comply with UL standards, connect the drive to a 3WYE type of mains 
power system. 
Output terminals for main circuit 
  Use a well-insulated motor, suitable for inverter operation. 
  When the AC drive output terminals U/T1, V/T2, and W/T3 are connected to 
the motor terminals U/T1, V/T2, and W/T3 respectively, the motor will rotate 
counterclockwise (as viewed on the shaft end of the motor) when a forward 
operation command is received. To permanently reverse the direction of 
rotation, switch over any two motor leads. 
Fo wa rd
Running