Mitsubishi S-K20 Magnetic Contactor – 20A AC Motor Starter Control Relay | S-K Series
Engineering Background
The Mitsubishi S-K20 is part of Mitsubishi Electric’s S-K Series of IEC-compliant magnetic contactors, engineered for demanding industrial motor control applications. Designed and manufactured under Mitsubishi Electric’s stringent quality standards, the S-K20 delivers reliable switching performance in environments where uptime is non-negotiable.
Product Positioning
Targeted at procurement engineers and MRO specialists sourcing proven motor control components for manufacturing lines, HVAC systems, pump stations, and conveyor drives. The S-K20 is a direct-fit replacement and new-installation solution for 3-phase AC motor starters rated up to 20A continuous current.
Complete Technical Specifications
- Model / SKU: S-K20
- Manufacturer: Mitsubishi Electric
- Series: S-K Series Magnetic Contactors
- Type: 3-Pole AC Magnetic Contactor
- Rated Current (Ie): 20A (AC-3 duty)
- Motor Rating: 5.5 kW / 7.5 HP @ 400V AC
- Rated Voltage (Ue): Up to 690V AC
- Coil Voltage: Available in 24V, 110V, 220V, 380V AC (specify on order)
- Auxiliary Contacts: 1NO + 1NC (standard)
- Utilization Category: AC-3 (squirrel cage motors)
- Standards Compliance: IEC 60947-4-1, JIS C 8201-4-1
- Mounting: DIN rail or screw mount
- Enclosure Rating: IP20 (open type)
- Operating Temperature: -10°C to +60°C
- Mechanical Life: ≥ 10 million operations
- Electrical Life (AC-3): ≥ 1 million operations
- Weight: Approx. 2,300 g (packaged)
- Dimensions (W × H × D): Per Mitsubishi S-K Series datasheet
Proven Application Environments
- 3-phase AC induction motor starting and stopping (DOL / direct-on-line)
- HVAC fan and pump motor control panels
- Conveyor and material handling drive circuits
- Compressor and refrigeration motor starters
- Machine tool and CNC auxiliary motor control
- Water treatment and wastewater pump stations
- Building automation and energy management systems
Engineering Advantages
- Low Power Consumption Coil: Reduced heat generation extends panel life and lowers energy costs
- Compact Footprint: Space-efficient design for high-density control panel layouts
- Tool-Free Wiring: Spring-clamp terminal option reduces installation time
- Modular Auxiliary Contact Blocks: Field-expandable without rewiring
- High Mechanical Durability: ≥10M operations ensures long service intervals
- IEC & JIS Dual Compliance: Accepted in global and Japanese industrial projects
- Direct Replacement Compatibility: Pin-compatible with legacy S-K Series installations
System Architecture & Signal Flow
The S-K20 operates within a standard motor control circuit (MCC) as follows:
- Power Circuit: L1/L2/L3 (line) → Main contacts (T1/T2/T3) → Motor terminals
- Control Circuit: PLC digital output or pushbutton → Coil terminals (A1/A2) → Contactor energizes
- Interlock: 1NO auxiliary contact feeds back to PLC input for run confirmation; 1NC used for interlocking in reversing or star-delta starters
- Overload Protection: Pair with Mitsubishi TH-K Series thermal overload relay for complete motor protection
- Upstream Protection: Coordinate with Mitsubishi NF or NV Series MCCB for short-circuit protection
Sourcing & Quality Verification
- All units sourced through verified Mitsubishi Electric authorized distribution channels
- Each unit inspected for OEM labeling, date codes, and packaging integrity prior to dispatch
- Counterfeit risk mitigation: serial number and hologram verification available on request
- Certificate of Conformance (CoC) and test reports available for project documentation
- Long-term storage units maintained in climate-controlled warehouse conditions
Procurement Process
- Confirm coil voltage required for your control circuit (24V / 110V / 220V / 380V AC)
- Verify auxiliary contact configuration (standard 1NO+1NC or add-on blocks)
- Submit RFQ via Konmask.com product page or email [email protected]
- Receive quotation with lead time, CoC availability, and shipping options within 24 hours
- Place order — secure checkout with T/T, PayPal, or credit card accepted
- Dispatch within 1–3 business days; DHL / FedEx / UPS express available
Technical FAQ
Q: What is the difference between S-K20 and S-K21?
A: The S-K21 includes an additional auxiliary contact block as standard. The S-K20 uses the base 1NO+1NC configuration with optional add-on blocks.
Q: Can the S-K20 be used for star-delta starting?
A: Yes, when used in a set of three contactors (main, star, delta) with appropriate interlocking via the NC auxiliary contacts.
Q: Is the S-K20 compatible with Mitsubishi FR-E700 / FR-D700 inverter bypass circuits?
A: Yes, the S-K20 is suitable for bypass contactor duty when the inverter output is isolated prior to switching.
Q: What thermal overload relay pairs with the S-K20?
A: The Mitsubishi TH-K20 or TH-K Series overload relay is the recommended companion device for complete motor protection.
Q: Do you provide documentation for customs clearance?
A: Yes — commercial invoice, packing list, and HS code declaration (HS 8536.49) are provided with every shipment.
© 2026 Konmask.com. All rights reserved.
Original Source: https://Konmask.com
Contact: [email protected] | +0086 19859288691
