Mitsubishi S-T35 AC200V Magnetic Contactor

The S-T35 AC200V is a 3-pole non-reversing contattore magnetico Di Mitsubishi Electric MS-T Series. It has a rated current of 40A, compatible with 18.5kW @ 400V three-phase motors. Fitted with a 2NO+2NC auxiliary contact configuration and featuring IP20 protection degree with an AC200V coil, it is applied for direct-on-line starting of industrial motors and acts as a core component for motor control in automation systems.

1. Spiegazione del codice modello

Definizione completa del modello: S-T35 AC200V = Mitsubishi MS-T Series, frame size 35, AC200V coil, 3-pole 40A non-reversing magnetic contactor

2. Specifiche tecniche principali

3. Elenco completo dei modelli (MS-T Series Non-reversing Contactors)

4. Modelli sostitutivi & Confronto della concorrenza

4.1 Mitsubishi Internal Replacements

4.2 Cross-brand Competitor Comparison

5. Ambienti applicativi & Casi di settore

5.1 Applicazioni consigliate

Controllo motori industriali: Direct-on-line starting for three-phase motors such as pumps, tifosi, compressori e trasportatori

Attrezzatura OEM: Supporting machine tools, macchine per l'imballaggio, printing machines and textile machinery

Realizzazione di impianti elettrici: Control of critical motors including air conditioning units, fire water pumps and drainage pumps

Industria generale: Motor control for production lines, automation equipment and material handling systems

Strutture commerciali: Control of refrigeration units, ventilation equipment and water pumps

5.2 Not Recommended Applications

Single-phase Motor Control: 3-pole design not suitable for single-phase circuits

High-frequency Start-Stop: Sopra 1200 cycles per hour will shorten service life

High Altitude (>2000M): È necessario un declassamento (10% reduction per 1000m elevation rise)

Severe Vibration Environments: Extra reinforcement is required to avoid malfunction

Corrosive Environments: IP20 protection is insufficient; additional enclosure is needed

5.3 Casi applicativi tipici

Caso 1: Fan System in Food Processing Plant

Attrezzatura: 3 sets of 18.5kW centrifugal fans, 400V trifase

Configurazione: S-T35 AC200V + TH-T35 thermal overload relay + moulded case circuit breaker

Risultato: Realizes sequential start-up and overload protection; the system operates stably with zero faults over 3 anni.

Caso 2: Water Pump Control in Wastewater Treatment Plant

Attrezzatura: 5 sets of 15kW submersible pumps, 400V trifase

Configurazione: S-T35 AC200V + PLC linkage control + GV2P32 motor circuit breaker

Caratteristiche: Low power design reduces cabinet temperature rise; 2NO+2NC contacts meet the demands of status monitoring and alarm output.

6. Risoluzione dei problemi & Maintenance Manual

6.1 Difetti comuni & Soluzioni

6.2 Maintenance Procedures

1. Ispezione giornaliera (Settimanale)

Check appearance for abnormal heat, odour or noise

Ensure terminals are tight with no overheating marks

Test auxiliary contacts to confirm synchronous operation with main contacts

2. Manutenzione ordinaria (Ogni 6 Mesi)

Cut off power and remove dust from contactor and core surface

Inspect main and auxiliary contacts for burning and oxidation

Test coil resistance and insulation performance

3. Manutenzione annuale

Check lubrication of mechanical parts and apply grease if needed

Verify operational flexibility and reliability

Retighten all electrical connections and replace aged components

6.3 Quick Diagnosis Tips

No pull-in? Check voltage and coil resistance first.

Loud noise? Clean core; replace if shading ring breaks.

Burned contacts? Limit current and reduce switching cycles.

Signal error? Inspect linkage and correct NO/NC wiring.

7. Selezione & Linee guida per l'installazione

7.1 Regole di selezione

Corrispondenza attuale: Motor Full Load Current (FLA) ≤ 40A; optimal for 18.5kW @ 400V motors

Tensione della bobina: Confirm control circuit voltage is AC200V to avoid mismatch

Coordinamento della protezione: Use with thermal overload relays (per esempio. TH-T35) and motor circuit breakers

Derating for High Temperature: Declassare 1% per ℃ above 40℃

7.2 Note di installazione

Direzione di montaggio: Installazione verticale (allowable deviation: ±15°) to guarantee arc extinguishing performance and mechanical life

Liquidazione: Reserve 10mm space on left & Giusto, 20mm on top & bottom for heat dissipation

Wiring Standard: 1.5-35mm² copper wire for main circuit (coppia: 6-8Nm); 0.5-1.5mm² copper wire for control circuit (coppia: 0.8-1.2Nm)

Interlock for Reversing Operation: Fit mechanical interlock to prevent phase short circuit

Protection for Harsh Environments: Install extra enclosure for dusty or humid conditions

8. Production Status & Soluzioni sostitutive

Current Status of S-T35 AC200V: In produzione, no discontinuation plan (as of June 2026)

Aggiornamento & Opzioni di sostituzione:

1. Aggiornamento funzionale: S-T35BC/SA series (built-in surge suppressor to reduce external components)
2. Aggiornamento intelligente: Mitsubishi NF series (with communication function for remote monitoring)
3. Alternativa domestica: Chint NXC-40, Delixi CDC1 series (lower cost with equivalent performance)

Application Cases of Mitsubishi S-T35 AC200V Magnetic Contactor

Featuring a 40A rated current, 2NO+2NC auxiliary contacts and low-power AC200V coil, the S-T35 AC200V is widely used for 18.5kW @ 400V three-phase motor control. It serves industries including water treatment, lavorazione degli alimenti, produzione automobilistica, tessile & dyeing, building HVAC, delivering reliable solutions for direct-on-line starting and status monitoring.

1. Overview of Main Application Fields

The S-T35 AC200V is compatible with 18.5kW @ 400V (or 11kW @ 220V) three-phase squirrel-cage induction motors. Typical applications are listed below:

2. Detailed Industry Application Cases

Caso 1: 1+1 Standby Control System for 15kW Submersible Pumps in Wastewater Treatment Plant

Contesto del progetto

Phase II project of an urban wastewater treatment plant. Five aeration tanks are equipped with 15kW submersible pumps for 24-hour continuous aeration. The system requires automatic duty/standby switching and automatic alarm upon faults.

Equipment Configuration

Main units: 5 sets of 15kW 400V three-phase submersible pumps

Control components: S-T35 AC200V contactor + TH-T35 thermal overload relay + GV2P32 motor circuit breaker + Mitsubishi FX3U PLC

Auxiliary components: GVAE11 auxiliary contact block (monitoraggio dello stato) + Audible & visual alarm + Manual/Auto selector switch

Solution Features

1. Redundant design: Independent control circuit for each pump to ensure uninterrupted operation
2. Status monitoring: 2NO+2NC contacts of S-T35 connect to PLC and alarm system for real-time status feedback
3. Risparmio energetico: 18VA pull-in power and 3.8W holding power reduce energy consumption and cabinet temperature rise
4. Multi-level protection: Circuit breaker for short-circuit protection, thermal relay for overload protection and contactor for circuit breaking to ensure equipment safety

Application Results

Stable operation for 3 years with zero unplanned shutdown

Automatic switching time ≤ 2 secondi, meeting process continuity requirements

15% energy saving compared with traditional contactors

40% lower maintenance cost and high versatility of spare parts

Caso 2: Temperature Control System for 18.5kW Centrifugal Fans in Food Processing Plant

Contesto del progetto

The sterilization workshop of a dairy plant needs to maintain a constant temperature of 120℃. Three 18.5kW centrifugal fans are deployed to automatically adjust operating quantity according to ambient temperature for energy saving.

Equipment Configuration

Main units: 3 sets of 18.5kW 400V three-phase centrifugal fans

Control components: 3 × S-T35 AC200V contactors + Temperature sensors + PLC Mitsubishi + HMI

Protection components: Moulded case circuit breaker + Relè termico + Relè di protezione sequenza fasi

Solution Features

1. Graded control: Automatically run 1/2/3 fans according to temperature ranges (≤115℃ / 115-125℃ / ≥125℃)
2. Avviamento stella-triangolo: Reduces inrush current; the contactor withstands high starting impulse current effectively
3. Visualization: HMI displays real-time operating status, current and temperature of each fan
4. Maintenance reminder: Cumulative runtime recording reminds users of regular contactor maintenance

Application Results

Temperature control accuracy improved to ±1℃, product yield increased by 3%

22% risparmio energetico, saving approximately 120,000 RMB on electricity annually

Extended fan service life and reduced replacement frequency

Simplified operation with less manual intervention

Caso 3: Conveyor Interlock Control System in Auto Parts Factory

Contesto del progetto

The assembly line of an automotive seat factory consists of 12 conveyors driven by 15kW motors. The system requires sequential start-up from feed end to discharge end, reverse sequence shutdown, and full-line shutdown protection once any conveyor fails.

Equipment Configuration

Main units: 12 sets of 15kW 400V three-phase conveyor motors

Control components: 12 × S-T35 AC200V contactors + PLC Mitsubishi + 6 pulsanti di arresto di emergenza + Safety relay

Signal system: 12 × GVAE11 auxiliary contact blocks (feedback sullo stato) + 24 spie luminose (operation/fault)

Solution Features

1. Interlock logic: PLC realizes interlock between conveyors via contactor auxiliary contacts to prevent material accumulation
2. Progettazione della sicurezza: Emergency stop signal directly cuts off coil power of all contactors with response time ≤ 0.1 secondo
3. Fast fault diagnosis: Contactor status uploaded to PLC for quick fault location
4. Progettazione modulare: Unified model reduces spare parts inventory and maintenance costs

Application Results

Production line failure rate reduced by 60%, production capacity increased by 15%

Average fault troubleshooting time shortened from 45 minutes to 5 minuti

Improved operational safety with zero safety incidents

30% lower spare parts cost and higher maintenance efficiency

Caso 4: Dual-motor Control System for Carding Machine in Textile Mill

Contesto del progetto

Renovation of BEFAMA CRIII carding machine in a wool textile mill. The original 37kW wound rotor motor with large starting current is replaced by a 7.5kW + 11kW dual-motor drive (total power 18.5kW), requiring synchronous start and balanced load.

Equipment Configuration

Main units: 7.5kW + 11kW 400V three-phase dual motors

Control components: 2 × S-T35 AC200V contactors + Mitsubishi inverter + PLC + Current sensors

Protection components: 2 × thermal overload relays + Short-circuit protection circuit breaker

Solution Features

1. Load balancing: PLC monitors motor current via sensors and dynamically adjusts inverter output
2. Smooth start: Combined inverter and contactor reduces starting current from 68A to 28A and minimizes grid fluctuation
3. Energy-saving operation: Motor speed automatically adjusted according to load, 30% energy saved
4. Fault protection: Both contactors trip simultaneously if either motor is overloaded to avoid equipment damage

Application Results

Starting current reduced by 59%, eliminating grid fluctuation

30% risparmio energetico, saving approximately 80,000 RMB on electricity annually

Extended equipment service life, maintenance cycle prolonged to 1 anno

Improved product quality and wool sliver uniformity by 2%

3. Application Classification & Linee guida per la selezione

3.1 In-depth Analysis of Applicable Scenarios

3.2 Scenari non consigliati & Alternative

4. Riepilogo & Raccomandazioni per la selezione

4.1 Application Value Summary

Alta affidabilità: 10 million mechanical cycles and 1 million electrical cycles (AC-3 40A/400V) for long-term industrial operation

Efficienza dei costi: Basso consumo energetico (18VA pull-in, 3.8W holding) cuts operational cost and heat generation inside cabinets

Flexibility: 2NO+2NC auxiliary contacts support status monitoring, alarm and interlock functions

Buona compatibilità: Matches GV2/GV3 motor circuit breakers and TH-T thermal overload relays to form a complete protection system

4.2 Mnemonico di selezione

Ideal match for 18.5kW motors, S-T35 is your first choice

AC200V coil fits well, low power saves energy all the way

2NO plus 2NC contacts complete, for monitoring and alarm needs

IP20 solid protection, stable performance in industrial sites

4.3 Application Optimization Suggestions

1. Corrispondenza della protezione: Equip with thermal overload relays (per esempio. TH-T35) and motor circuit breakers for dual protection against overload and short circuit.
2. Installation Standard: Montare verticalmente (±15°); reserve sufficient heat dissipation space (10mm sinistra/destra, 20mm top/bottom).
3. Specifiche di cablaggio: 1.5-35mm² copper wire for main circuit (torque 6-8Nm); 0.5-1.5mm² copper wire for control circuit (torque 0.8-1.2Nm).
4. Ciclo di manutenzione: Inspect contacts every 6 mesi; replace frequently operated contactors annually.
5. High-temperature Adaptation: Declassare 1% per ℃ when ambient temperature exceeds 40℃.