General Information

Core Description

The SP3401 is an Emerson Control Techniques Unidrive SP complete inverter drive featuring a 380V to 480V three-phase input rating. Fully compatible with size 3 wall-mount backplates, this intelligent unit works seamlessly with standard induction or servo motors to deliver flexible open-loop, closed-loop, or servo motor control configurations and highly stable, energy-saving industrial network communication.

Specific Application

Speed and torque control of high-efficiency asynchronous induction motors or permanent magnet servo motors in manufacturing plant systems.

Fan, pump, and compressor automation loops requiring continuous variable-speed operation and integrated Dynamic Braking resistor controls.

High-performance positioning loops utilizing modular multi-protocol encoder feedback accessories inside centralized motor control cabinets.

System Compatibility, Alternative Models, and Differences

System Compatibility:
Fully compatible with standard industrial power supplies (TN-S, TN-C-S, TT, and IT networks up to 480V) and interfaces directly with SM-Keypad, SM-Keypad Plus, and SM automation/fieldbus option modules (such as PROFIBUS, DeviceNet, and Ethernet).

Alternative Model (Heavy-Duty/Higher-Step Sibling):
SP3402 (Unidrive SP Size 3 Alternative Step)

Key Differences between SP3401 and SP3402:

Continuous Current Delivery: The SP3401 provides a continuous output current of 35A (Normal Duty) and 32A (Heavy Duty), whereas the SP3402 delivers higher currents of 43A (Normal Duty) and 40A (Heavy Duty).

Motor Power Output Steps: The SP3401 is tailored for nominal motor loads up to 18.5 kW (25 hp) under standard duty, while the SP3402 extends performance capacities up to 22 kW (30 hp).

Braking Resistor Matching: While both are size 3 drives sharing a minimum braking resistance boundary of 18 ohms, the SP3402 draws a higher peak power level during deceleration sequences due to its increased current handling capacity.

Ordering Information

Installation & Troubleshooting FAQ

Q1: What are the strict clearance guidelines required when executing cabinet layout plans for this drive?

A: For a size 3 Unidrive SP, you must maintain a physical top and bottom clearance of at least 100 mm (4 inches) inside the enclosure. Additionally, a minimum side-to-side clearance of 30 mm (1.181 inches) must be kept between adjacent drives or enclosure walls to ensure convective or forced airflow paths remain unrestricted.

Q2: Under what conditions must the internal EMC filter be physically removed from the assembly?

A: The internal radio-frequency suppression EMC filter must be completely disconnected if the drive is deployed as part of a regenerative (regen) system layout, or if it is connected to an ungrounded IT power supply system. Leaving the filter connected on an IT supply can risk damage to internal drive components during line-to-ground faults.

Q3: What is the proper parameter configuration step to ensure correct motor thermal protection?

A: You must never rely on the factory default software values to protect your connected motor. It is essential to enter the exact motor nameplate current rating into parameter 0.46 (Motor Rated Current) immediately during commissioning. This parameter directly calculates and governs the active electronic thermal overload protection curve.

Q4: Why does the drive display show an instantaneous blanking state immediately after an unexpected fault?

A: An immediate display blackout points to a severe internal hardware fault that has disrupted the lower low-voltage logic supply power. In this state, you must assume the high-voltage internal capacitors have failed to dump energy through their normal internal discharge resistors; wait at least 10 minutes and verify with a voltmeter before accessing any power terminals.

Q5: How can field engineers verify the internal software version running inside an existing drive module?

A: The complete system software version uses a standard xx.yy.zz notation format. Operators can quickly read the first segments by checking Pr 11.29 (or Pr 0.50) which shows the xx.yy value, and then reference Pr 11.34 to view the final zz software sub-code.