SPMD1401

Emerson SPMD1401 is the DC-input inverter stage of the Control Techniques Unidrive SPM modular drive platform. It supplies variable-frequency AC power to the motor, while the rectifier and input line reactor are separate parts of an AC-fed installation. This separation supports common-DC-bus arrangements and engineered regenerative systems. The module belongs to frame size 1 and the 380–480 V AC supply class of the complete drive; the inverter itself connects to the DC bus, not directly to the AC mains.

The power stage has a Normal Duty continuous output rating of 205 A and nominal motor power of 110 kW at 400 V. Its Heavy Duty nominal motor power is 90 kW at 400 V. The standard rating conditions are 40°C ambient, 3 kHz switching frequency and altitude up to 1000 m; higher switching frequencies, temperature or altitude require the applicable derating. Normal Duty suits lower-overload applications such as fans and pumps, while Heavy Duty provides the overload basis for constant-torque loads. An internal brake transistor is fitted. A braking resistor is a separately selected system component; its resistance, thermal protection and energy rating must match the duty.

Motor-control functions depend on the fitted master control pod and the completed drive configuration. The Unidrive SPM platform supports open-loop, rotor-flux-control, closed-loop vector and servo operation with the corresponding motor and feedback arrangement. Parallel installations need matched module connections, output sharing chokes and current derating. The control master pod carries the programming, feedback and option-module interfaces, whereas a slave pod connects to the master control chain. An external 24 V supply operates the module fans; cooling and bus protection remain essential parts of the cabinet design.