Description
The Emerson SPMC2402 is a controlled input rectifier module in the Unidrive SPM family from Emerson (Control Techniques). Unlike a fixed-diode front end, it uses a dual half-controlled thyristor bridge to convert 380–480 VAC three-phase mains into a regulated DC link for SPMD inverter modules and common-DC-bus drive systems. The SPMC2402 is the controlled-rectifier equivalent of the SPMU2402, with the important distinction that soft start is built in — no external charging resistor and contactor are required.
Application Scenarios
A steel-service-center saw was running a 400 V Unidrive SP regen system with three parallel SPMD inverter modules feeding the main saw spindle and two material-handling axes. The original uncontrolled front end had been damaged during a supply disturbance, and the plant’s maintenance team wanted to avoid rebuilding the external charging circuit that had already failed once. The replacement had to carry the full DC link load of the parallel inverters, work with the existing line reactor and bus cabling, and give the drives an unambiguous fault signal so they would disable safely if the supply front end failed. The team selected the SPMC2402 because it is the specified controlled rectifier for 400 V parallel SPMD configurations, supplies built-in soft start, and its dual-stage topology matched the 2 × 308 A input / 2 × 345 A DC current profile already engineered into the cabinet. After installation, the saw returned to full duty with clean pre-charge behavior and a reliable rectifier-status interlock into the drive enable circuits.
In a second case, a paper-machine sectional drive with a shared DC bus was being expanded. The existing uncontrolled rectifier was already at the limit of its practical bus capacitance, and the superintendent was unwilling to add a second complete front end. By fitting a SPMC2402 in place of the aging uncontrolled unit — keeping the same INL412 line reactor and 2 × 120 mm² cabling — the plant gained the controlled pre-charge and fault-reporting behavior needed for the larger bus, and the expansion went ahead without reworking the main enclosure.
Parameter
| Parameter | Value / Description |
|---|---|
| Product Model | SPMC2402 |
| Manufacturer | Emerson / Control Techniques |
| Product Type | Controlled input rectifier module (dual half-controlled thyristor bridge) |
| Product Family | Unidrive SPM |
| Voltage Class | 400 V (380–480 VAC) |
| Input Voltage | 380–480 VAC, ±10 %, three phase, 50/60 Hz |
| Input Frequency | 48–65 Hz |
| Rectifier Stages | 2 (dual stage) |
| AC Line Current | 677 A (100 % normal duty motor current); 2 × 308 A typical, 2 × 312 A maximum |
| DC Link Current | 758 A (100 % normal duty motor current); 2 × 345 A DC typical |
| DC Output | 513–648 VDC (follows input voltage) |
| Topology | Dual half-controlled thyristor bridge (controlled rectifier) |
| Soft Start | Built in (no external resistor/contactor required) |
| Control / Auxiliary Supply | External 24 VDC, 3 A required for module operation; 4 A slow-blow fuse per supply pole |
| DC Bus Capacitance | Up to 132 mF with supply <25 kA fault level; 66 mF with INL412 line reactor |
| Recommended Line Reactor | INL412 (2 × INL402 equivalent duty) |
| Input Semiconductor Fuse | 450 A, IEC aR class |
| Series HRC Fuse | 400 A, IEC gG / UL Class J |
| AC Input Cable | 2 × 120 mm² (2 × 4/0 AWG) |
| DC Output Cable | 2 × 120 mm² (2 × 4/0 AWG) |
| Control Wiring | 0.5 mm² |
| Status Relay Contacts | 250 VAC / 6 A non-inductive; 4 A DC at ≤40 V; 400 mA DC at ≤250 V DC |
| Cooling | Forced-air cooling (internal fan) |
| Status Indicators | 2 × LEDs (Status 1 / Status 0) |
| Protection | Over-temperature (heatsink, PCB, snubber), phase loss, status input wire-break detection |
| Approximate Weight | Around 17–20 kg (dealer/manufacturer values differ; verify on the nameplate) |
| Dimensions | Published values vary by source (approximately 390 × 280 × 220 mm to 399 × 298 × 310 mm); verify against the unit rating label |
| Battery / Magnet | None |
