Key Technical Specifications
| Parameter | Value |
|---|---|
| Product Model | SK3202 |
| Manufacturer | Emerson / Control Techniques |
| Product Type | AC Variable Speed Drive |
| Power Rating | 0.75 kW (1 HP) |
| Input Voltage | 380–480 VAC, 3-Phase |
| Control Mode | Sensorless Vector / V/f |
| Overload Capacity | 150% for 60s (Heavy Duty) |
| Communication | Modbus RTU (Built-in) |
| Protection Class | IP20 (Chassis) |
| Output Frequency | 0–1500 Hz |
| Mounting | DIN Rail / Panel |
Product Introduction
The EMERSON SK3202 is a compact AC variable speed drive from the Commander SK series, engineered to control 3-phase induction motors up to 0.75 kW. It provides sensorless vector control for precise torque and speed regulation in applications ranging from conveyor belts to pump systems, eliminating the need for external encoders in standard duty cycles.This drive handles 150% overload for 60 seconds in heavy-duty mode, distinguishing it from lighter fan/pump-only units. The EMERSON SK3202 features built-in Modbus RTU and an onboard PID controller, reducing panel space and component count. I’ve seen these units run for 15+ years in dusty sawmills; the conformal coating on the PCB is the real hero here.
Installation & Configuration Guide
Preparation (10 min)
Verify motor nameplate FLA does not exceed the EMERSON SK3202 rated current. Confirm 3-phase 400V input power is stable. Gather wire strippers, crimpers, and a 2.5mm flathead screwdriver. Check the DIP switches on the front panel for input/output configuration before mounting.Removal (5–10 min)
Lock out/tag out main power. Wait 5 minutes for DC bus capacitors to discharge (verify <50V DC across +/- terminals). Disconnect motor (U/V/W), input power (R/S/T), and control wires. Remove DIN rail clips or panel mounting screws.Installation (10 min)
Mount EMERSON SK3202 vertically with 100mm clearance above/below for airflow. Reconnect power and motor cables using crimped ferrules. Ensure control wires are separated from power cables by at least 50mm to prevent noise coupling. Tighten all terminals to 0.5 Nm.Power-On & Test (10 min)
Apply control power first; verify keypad display illuminates. Run the “Quick Start” wizard (Menu 0) to input motor FLA, voltage, and Hz. Perform a static auto-tune with motor disconnected, then a rotating auto-tune with motor uncoupled. If the motor jerks during test, immediately stop and check phase rotation.
Troubleshooting Quick Reference
| Symptom | Probable Cause | Action |
|---|---|---|
| “OH” Fault | Overheat | Check fan operation; clean heatsink; verify ambient <40°C |
| “OC” Fault | Overcurrent | Check motor insulation; reduce accel time; verify FLA setting |
| “OL” Fault | Overload | Reduce load; check motor bearings; increase drive size |
| No Display | Control Power Loss | Measure 24V DC across CN1-1 & CN1-2; check fuse F1 |
| Erratic Speed | Noise Interference | Shield control cables; ground shield at drive end only |
| “E.Er” Fault | EEPROM Error | Power cycle; if persistent, replace drive |
Dimensions, Mounting & Wiring Notes
- Form Factor: Commander SK Size 2
- Mounting: DIN Rail (35mm) or Panel Mount (screw holes)
- Terminal Note: Control I/O uses removable plug-in terminal blocks; do not solder directly to board.
- Clearance: 100mm top/bottom, 50mm sides. Do not mount directly above heat-generating components like resistors.
FAQ
Is this the same as Control Techniques SK3202?
Yes. Emerson acquired Control Techniques, so EMERSON SK3202 and Control Techniques SK3202 are identical hardware. Firmware may vary slightly by production date, but form-fit-function is the same.I have a 0.55 kW motor, can I use this?
Yes, but verify the motor FLA is within the SK3202’s continuous current rating. I’ve seen people burn out small motors by setting drive current too high because “it’s a bigger drive.” Always match FLA, not just kW.Does it support Ethernet?
No. Native protocol is Modbus RTU over RS-485. For Ethernet, you need an optional fieldbus card (e.g., EtherNet/IP or Profinet option module).How do I reset a trip?
Press the STOP/RESET key on the keypad. If running, hold RUN while pressing STOP/RESET. If it trips immediately again, do not keep resetting; you’re likely destroying the IGBTs.What’s the difference between SK3202 and SK3203?
The SK3203 is the next size up (1.1 kW / 1.5 HP). If your motor FLA is within 80% of the SK3202’s max current, stick with the 3202. If you’re running near the limit, go to the 3203; drives hate living at 100% duty cycle.Can I use this for a single-phase motor?
No. The EMERSON SK3202 is designed for 3-phase induction motors only. Single-phase input is allowed on the power side, but output must be 3-phase.Is the keypad removable?
Yes. It uses a ribbon cable connector. You can mount it remotely up to 3 meters using an extension kit, which is great for hot or hard-to-reach panels.
