Top 5 Soft Starters Manufacturer in China – INOMAX AST Series | AC Motor Soft Starters 7.5‑1200kW, 220‑1140V | Replace ABB, Siemens, Schneider

INOMAX Low Voltage Soft Starters – AST6100, AST6800, AST7000 Series | Replace ABB PSR/PSTX, Siemens 3RW, ATS48 | 220V–1140V, Built‑in Bypass 1. Overview As a top 5 soft starters manufacturer in China and a leading AC motor soft starters manufacturer in China, INOMAX Technology Co., Ltd. specializes in the R&D and production of high‑performance low voltage soft starters. Our AST series are designed for three‑phase squirrel cage motors from 7.5kW up to 1200kW, covering voltage classes 220V, 380V, 400V, 440V, 480V, 525V, 600V, 690V and 1140V. We offer three complete series: cost‑effective online soft starter (AST6100), space‑saving built‑in bypass economic series (AST6800), and advanced full‑featured built‑in bypass series (AST7000). Being an AC motor soft starter manufacturer with over a decade of experience, we provide factory direct pricing, full‑load motor testing on every unit, and a <1% defect rate. Our soft starters are direct mechanical and electrical replacements for ABB PSR/PST/PSTX, Siemens 3RW30/3RW40/3RW44, Schneider ATS22/ATS48/ATS480, Danfoss MCD 200/500, and Rockwell SMC‑3/SMC‑50 – at 30‑50% lower cost and 2‑3 weeks lead time. With over 50,000 units installed globally in pumps, compressors, conveyors, crushers, fans, and HVAC, INOMAX has earned our reputation as a trusted soft starter supplier for OEMs, integrators, and distributors worldwide. Inomax built-in bypass soft starters AST6800 and AST7000 series product photos   LOW voltage intelligent online softstarters 2. Product Series Overview – Online vs. Built‑in Bypass Feature AST6100 Series (Online) AST6800 Series (Built‑in Bypass – Economy) AST7000 Series (Built‑in Bypass – Full Range) Topology Online (thyristors in circuit during run) Built‑in bypass contactor Built‑in bypass contactor Power range 7.5kW – 1200kW (380V) / up to 1000kW (690V) / up to 630kW (1140V) 5.5kW – 115kW (380‑480V) 7.5kW – 800kW (380‑480V) / up to 800kW (690V) Voltage classes 220V, 380V, 400V, 440V, 480V, 525V, 600V, 690V, 1140V 220V, 380V, 480V 220V, 380V, 400V, 440V, 480V, 525V, 600V, 690V Heat dissipation Higher (thyristors always conducting) Low (bypass relay after start) Low (bypass relay after start) Panel space Larger (no built‑in bypass) Compact (integrated bypass) Compact (integrated bypass, large power same compact footprint) Protection class IP20 (standard), IP54 optional IP20 IP20, IP54 optional for some models Starting modes 6 modes (current limit, voltage ramp, torque, kick start, current ramp, dual closed‑loop) 3 modes (voltage ramp, current limit, torque) 5 modes (adaptive control, constant current, current ramp, kick start, TVR soft stop) Protection functions 12 types 12 types 20 types (incl. ground fault, RTD, phase sequence) Communication RS485 Modbus RTU (standard) RS485 Modbus RTU (standard) RS485 Modbus RTU (standard); optional Profibus, Ethernet, DeviceNet Key features Most economical, wide power and voltage range, ideal for projects with external bypass contactor Cost‑effective bypass solution for small to medium power Advanced adaptive control, real‑time clock, event log, multi‑language LCD, PT100/RTD input, fire mode Typical applications Pumps, fans, conveyors, compressors where external bypass is acceptable or frequent starting Standard pumps, HVAC, small compressors, material handling Heavy duty pumps, crushers, mixers, marine, mining, critical processes Certifications CE, ISO CE, ISO CE, CCS (marine), ISO Price level Lowest (30‑50% below ABB/Siemens) Low (40‑50% below ABB/Siemens) Medium (30‑40% below ABB PSTX/Siemens 3RW44) When to choose which? AST6100 (online) – Best for cost‑sensitive projects, large power (>115kW), or when you already have external bypass contactors in your panel. AST6800 (built‑in bypass economy) – Ideal for standard motor control centers (MCC) up to 115kW where space is limited. AST7000 (built‑in bypass full range) – For demanding applications requiring advanced control and monitoring. As a leading AC motor soft starter manufacturer, we recommend AST7000 for critical infrastructure like water treatment and mining. 3. Key Features & Technical Specifications (Common across series) Being a top soft starter factory in China, we build every unit with rigorous quality control – 100% ICT, 100% no‑load function test, and 100% full‑load motor test. Parameter AST6100 AST6800 AST7000 Rated voltage 220‑1140V (±15%) 220‑480V (±10%) 220‑690V (±10%) Rated current 15A – 2200A (depending on model) 13A – 230A 23A – 1600A Frequency 50/60Hz (±2%) 50/60Hz 45‑66Hz Starting modes 6 3 (voltage ramp, current limit, torque) 5 (adaptive, constant current, current ramp, kick start) Stop modes Soft stop (0‑60s) / Free stop Free stop / Timed soft stop Free stop / TVR soft stop / Adaptive stop / Braking Initial voltage 30‑70% Ue 30‑80% Ue N/A (adaptive) Current limit 50‑500% Ie 50‑600% Ie 100‑600% Ie Starting ramp time 2‑60s 1‑120s 1‑180s (adaptive) Overload capacity 150% for 35s, 200% for 15s 150% for 35s, 200% for 15s 400% for 10s (Class 10/30) Built‑in bypass No Yes (integrated) Yes (integrated) I/O 4 DI, 3 DO, 2 RO 3 DI, 2 RO, 1 AO 6 DI (2 programmable), 4 RO, 1 AO, PT100 input Communication RS485 Modbus RTU RS485 Modbus RTU RS485 Modbus RTU (optional Profibus, Ethernet, DeviceNet) Display Digital LED or LCD Detachable LCD (English/Chinese) Large LCD, multi‑language, real‑time clock Protection functions Input/output phase loss, overload, over/under voltage, overcurrent, short circuit, imbalance, overheating Input/output phase loss, overload, overcurrent, underload, phase sequence, SCR short circuit Motor thermal model, underload, instantaneous overcurrent, ground fault, frequency, RTD, thermistor, restart delay, etc. Ambient temp -10°C to 40°C (derating to 60°C) 0°C to 55°C -10°C to 60°C Altitude ≤2000m (derating above) ≤1000m ≤1000m (derating 1%/100m above) Certifications CE, ISO CE, ISO CE, CCS, ISO 4. Industry Solutions & Application Cases 4.1 Pumping Stations – Municipal Water Supply Challenge: Water hammer during stop, high inrush current causing voltage dips. Solution: INOMAX AST7000-160 (160kW, 380V) with adaptive soft stop eliminates water hammer. Current limit start reduces starting current from 6x to 3x Ie. Customer Outcome: A municipal water company in Algeria replaced failed ABB PSTX170 with AST7000-160. After 18 months: zero failures, 22% energy saving, and soft stop completely removed pipeline vibration. They now standardize on INOMAX as their preferred soft starter supplier. 4.2 Mining – Belt Conveyor Challenge: High starting torque required (200% torque), frequent trips due to overload. Solution: INOMAX AST6100-250 (250kW, 690V) online soft starter with current limit start set to 400% Ie and starting ramp 20s. Customer Outcome: A copper mine in Zambia installed AST6100-250 on a 200m belt conveyor. Starting current reduced from 1800A to 600A, eliminating transformer trips. The mine now lists INOMAX as an approved AC motor soft starter manufacturer for all expansion projects. 4.3 HVAC – Chilled Water Pump Challenge: Limited space in MCC, need energy savings and remote monitoring. Solution: INOMAX AST6800-055 (55kW, 380V) built‑in bypass soft starter. Customer Outcome: A 5‑star hotel in Dubai installed AST6800-055 on a primary chilled water pump. Energy consumption dropped by 18%, and the maintenance team monitors pump current remotely via Modbus RTU to the BMS. 4.4 Crusher (Jaw Crusher) Challenge: Extremely high inertia, long starting time, risk of locked rotor. Solution: INOMAX AST7000-400 (400kW, 480V) with constant current start mode set to 450% Ie and starting limit time 40s. Customer Outcome: A quarry in Brazil replaced a failed Siemens 3RW44 with AST7000-400. The crusher now starts smoothly in 28s, and the event log helps diagnose jam conditions. The quarry’s engineer commented: “Finally found a reliable soft starter manufacturer that delivers fast.” 4.5 Screw Compressor Challenge: Frequent start/stop (10‑12 times per hour), need to reduce mechanical stress on drive belts. Solution: INOMAX AST6800-090 (90kW, 380V) built‑in bypass. Customer Outcome: A compressed air system provider in Thailand uses AST6800‑090 on all their screw compressor packages. After 2 years, belt life increased by 40%, and no soft starter failures. They now promote INOMAX as their exclusive AC motor soft starter partner. 4.6 Irrigation Pump (Solar Grid Hybrid) Challenge: Wide voltage variation (320V‑480V) due to solar and grid switching. Solution: INOMAX AST6100-075 (75kW, 380‑480V) with wide operating voltage range (±25%). Customer Outcome: An agricultural project in Morocco equipped 12 irrigation pumps with AST6100-075. The soft starters handle voltage fluctuations without tripping, and dry run protection saved three pumps from burning. 4.7 Marine – Ballast Pump Challenge: CCS certification required, high humidity environment. Solution: INOMAX AST7000-132 (132kW, 690V) with built‑in bypass, CCS certified. Conformal coated PCB protects against salt mist. Customer Outcome: A Chinese shipyard installed AST7000-132 on a ballast pump for a 50,000 DWT bulk carrier. Passed CCS inspection without issues. Now used on 12 vessels, strengthening our position as a top 5 soft starters manufacturer in China in the marine segment. 5. Direct Replacement Cross‑Reference Table (INOMAX vs. ABB, Siemens, Schneider, Danfoss) As an experienced soft starter factory, we have mapped hundreds of competitor models to our AST series. Below is a partial list – contact us for a complete cross‑reference. Brand Competitor Model Power (kW) INOMAX Equivalent Series ABB PSR30‑600 7.5‑11kW AST6800‑011 AST6800 ABB PSE72‑600 30‑37kW AST6800‑037 AST6800 ABB PSTX72‑600 37‑45kW AST7000‑045 AST7000 ABB PSTX210‑600 110‑132kW AST7000‑132 AST7000 ABB PSTX470‑600 250‑315kW AST7000‑315 AST7000 Siemens 3RW30 17A 7.5kW AST6800‑7.5 AST6800 Siemens 3RW40 106A 55kW AST6800‑055 AST6800 Siemens 3RW44 370A 200kW AST7000‑200 AST7000 Siemens 3RW44 720A 400kW AST7000‑400 AST7000 Schneider ATS22 75kW 75kW AST6100‑075 AST6100 Schneider ATS48 210A 110kW AST7000‑110 AST7000 Schneider ATS480 470A 250kW AST7000‑250 AST7000 Danfoss MCD 200 37kW 37kW AST6800‑037 AST6800 Danfoss MCD 500 160A 90kW AST7000‑090 AST7000 Rockwell SMC‑3 100A 45kW AST6800‑045 AST6800 6. Competitor Comparison: INOMAX vs. ABB, Siemens, Schneider (Manufacturer Benchmark) How does a top 5 soft starters manufacturer in China compare with legacy European brands? See for yourself. Feature INOMAX AST7000 ABB PSTX Siemens 3RW44 Schneider ATS480 Control mode Torque, voltage ramp, current limit, adaptive Torque, voltage, current limit Torque, voltage, current limit Torque, voltage ramp Built‑in bypass Yes (all powers) Yes (optional on some) Yes (optional) Yes (standard) Voltage range 220‑690V 208‑690V 200‑480V 208‑690V Max power 800kW (380V) 1000kW 315kW 1200kW Starting capacity Class 10/30 Class 10/30 Class 10/30 Class 10/30 Starts per hour 20 10 15 10 I/O 4 DI, 3 RO, 1 AO, PT100 4 DI, 2 RO 4 DI, 2 RO 4 DI, 3 RO, 1 AO Communication Modbus RTU (std), Profibus/Ethernet (opt) Modbus RTU (std), Profibus (opt) Profibus (opt) Modbus TCP, Profinet, Ethernet/IP LCD keypad Yes (detachable) Yes (optional) Yes (built‑in) Yes (detachable) Real‑time clock Yes No Yes Yes Event log 99 events 10 events 50 events 20 events Factory direct price 30‑40% lower Premium Premium High Lead time (factory) 2‑3 weeks 12‑20 weeks 16‑30 weeks 10‑16 weeks Key takeaway: INOMAX, as an AC motor soft starter manufacturer with our own R&D and production, delivers same or better features at 30‑50% lower cost with much faster delivery than European brands. 7. Online Soft Starter (AST6100) vs. Built‑in Bypass Soft Starter (AST6800/AST7000) – Technical Explanation Many customers ask: What is the difference between an online soft starter and a built‑in bypass soft starter? As a soft starter manufacturer that produces both types, we explain: Online Soft Starter (AST6100) Operation: Thyristors remain in the circuit during the entire motor running time. Heat dissipation: Continuous heat loss (approx. 360W for a 100A motor). Pros: Lower initial cost, no bypass relay to fail, works for frequent starting (20 starts/hour). Cons: Higher energy cost, requires panel ventilation. Best for: Frequent starting cycles (crushers, mixers) or when external bypass is already in panel. Built‑in Bypass Soft Starter (AST6800 / AST7000) Operation: After motor reaches full speed, a built‑in bypass contactor shunts the thyristors. Heat dissipation: After bypass, near zero heat loss. Pros: Energy saving (200‑1000 kWh/year for a 55kW pump), cooler panel, longer SCR life. Cons: Slightly higher upfront cost, bypass contactor has limited mechanical life (100k operations – sufficient for most applications). Best for: Continuous duty pumps, fans, compressors, HVAC. Our recommendation as a manufacturer: For 24/7 applications, choose bypass (AST6800/AST7000) to save energy. For heavy cyclic duty, choose online (AST6100). 8. Protection Functions & Fault Codes – Quick Reference Protection AST6100 AST6800 AST7000 Description Input phase loss Yes Yes Yes Trips if any input phase missing (＜3s) Output phase loss Yes Yes Yes Trips if motor cable disconnected Overload (electronic) Yes (Class 10/30) Yes (inverse time) Yes (thermal model, adjustable) Inverse time protection based on motor current Overcurrent (starting) Yes Yes Yes Trips if current >5x Ie for set time Overcurrent (running) Yes (200‑400% adjustable) Yes Yes (instantaneous) Protects against load surge Undercurrent Yes (10‑90% adjustable) Yes Yes Detects dry run, belt break, pump cavitation Overvoltage Yes (100‑130% Ue) Yes Yes Input voltage too high Undervoltage Yes (40‑90% Ue) Yes Yes Input voltage too low Current imbalance Yes (＞30% trip) Yes Yes Detects motor winding fault Short circuit (SCR) Yes (＜0.1s) Yes Yes Instantaneous trip on >10x Ie Heatsink overtemperature Yes (80°C trip) Yes Yes Fan failure or high ambient Ground fault No No Yes (optional) Leakage current protection Motor thermistor (PTC) No (optional) No Yes (input) Direct PTC sensor connection RTD/PT100 No No Yes (6 inputs with expansion) Bearing/winding temperature 9. Frequently Asked Questions (FAQ) Q1: Who is INOMAX? Are you a genuine soft starter manufacturer or just a trader? A: INOMAX Technology Co., Ltd. is a top 5 soft starters manufacturer in China with our own R&D, SMT production lines, and full‑load test benches. We are not a trading company. We design and manufacture all AST series soft starters in our Shenzhen factory, with an annual output of over 50,000 units. You are welcome to visit our factory and witness our production and quality control. Q2: What is the difference between a soft starter and a VFD? When should I use a soft starter instead of a variable frequency drive? A: A soft starter controls voltage during start/stop only, while a VFD controls frequency and voltage continuously. Use a soft starter for motor when you need to limit inrush current and reduce mechanical stress but do not need speed regulation. As a dedicated AC motor soft starter manufacturer, we produce soft starters optimized for constant speed applications like pumps, fans, and compressors – at 30‑50% lower cost than VFDs. Q3: Can I replace an ABB PSR or PSTX soft starter directly with an INOMAX AST series without changing panel wiring? A: Yes. INOMAX AST6800 and AST7000 have similar terminal layouts and mounting dimensions to ABB PSR/PSTX for most power ranges. We provide a cross‑reference guide and parameter migration tool. Being a soft starter manufacturer with deep engineering support, we can also customize adapter plates for legacy panels. Q4: How do I select / choose a soft starter for a pump? What sizing calculation should I use? A: For centrifugal pumps, select a soft starter with rated current ≥ motor nameplate FLC. Set starting mode to current limit (350‑400% Ie) and enable soft stop (10‑20s) to eliminate water hammer. Use our online sizing tool or contact our engineers – we offer free selection support as part of our AC motor soft starter manufacturer service. Q5: What is the typical soft starter price for a 55kW / 75HP unit from a Chinese manufacturer? A: An INOMAX AST6800‑055 (55kW, built‑in bypass) is typically priced 40‑50% lower than ABB PSE105 or Siemens 3RW40. For example, ABB PSE105 list price ~1,800,������������������������������������������������ 1,800,INOMAXfactorydirectprice 900. Volume discounts further reduce cost. Request a quote – we are a soft starter factory, so you eliminate distributor markups. Q6: Does INOMAX soft starter support Modbus RTU communication for remote monitoring? A: Yes. All AST series include RS485 Modbus RTU as standard. You can read motor current, voltage, status, fault codes, and send start/stop/reset commands over Modbus – ideal for integration with SCADA or PLC. AST7000 also optionally supports Profibus, Ethernet/IP, and Modbus TCP. Q7: What is the advantage of buying from a top 5 soft starters manufacturer in China versus a local distributor of European brands? A: When you buy directly from INOMAX, you get: (1) 30‑50% lower price (no brand premium), (2) 2‑3 weeks lead time vs 12‑30 weeks for ABB/Siemens, (3) direct technical support from our engineers, (4) customization (e.g., special voltages, enclosures, communication protocols). We are a soft starter supplier that partners with you for mutual growth. Q8: What is the maximum starts per hour for INOMAX soft starters? A: AST6100 and AST6800 support up to 20 starts per hour (standard), AST7000 supports 10‑20 depending on power. For higher frequency, use online type (AST6100) and external bypass contactor. Contact our factory for special duty designs. Q9: Does INOMAX produce a 690V soft starter for mining? What about 1140V? A: Yes. As a full‑range AC motor soft starter manufacturer, we offer AST6100 and AST7000 in 690V (±15%) up to 800kW, and 1140V up to 630kW (AST6100‑S11 series). These are widely used in mining conveyors, underground pumps, and offshore platforms. CCS marine certification available for AST7000. Q10: How do I wire a soft starter? Do you provide wiring diagrams? A: Yes, every unit comes with a user manual including detailed wiring diagrams for star and delta connection. We also provide free remote commissioning support via WhatsApp/TeamViewer. As a soft starter manufacturer, we have helped thousands of electricians install our products correctly. Q11: What are common soft starter failure causes and solutions? A: Most common: (1) Soft starter trips on overcurrent – check load, reduce current limit, increase ramp time. (2) Soft starter overheats – clean fan, improve panel ventilation. (3) Bypass contactor not engaging – check relay output settings. (4) No display – check control voltage. Refer to manual Chapter 7 for full fault table. Our after‑sales team responds within 24 hours. Q12: How long is the warranty and what does it cover? A: INOMAX offers 24 months standard warranty (extendable to 36 months for volume orders). Coverage includes manufacturing defects, SCR failures, PCB issues. Excludes misuse. As a responsible AC motor soft starter manufacturer, we stock spare parts for 10 years. Q13: Can I get a sample unit for testing before ordering in bulk? A: Yes. We support sample orders for qualified distributors and large OEMs. Contact us with your motor details and current soft starter model. We will recommend an equivalent and send a unit for evaluation with 30‑day return policy. Q14: Where can I find the soft starter user manual and PC software? A: All manuals (AST6100, AST6800, AST7000) and PC configuration tool (for AST7000) are available for free download on our website after registration. No license fee required – because we believe in transparent partnership. Q15: How do I become a distributor for INOMAX soft starters? What benefits do you offer? A: We are looking for distributors in Southeast Asia, Middle East, Africa, Latin America, and Eastern Europe. Benefits as a top 5 soft starters manufacturer in China: exclusive territory, lowest price guarantee (factory direct), technical training, marketing support, sample units, and after‑sales inventory. Contact our distribution team today. 10. Why Choose INOMAX – A Top 5 Soft Starters Manufacturer in China? True manufacturer – Not a trading company. Own R&D, SMT line, full‑load test facility. Complete portfolio – Online (AST6100) and built‑in bypass (AST6800, AST7000) from 7.5kW to 1200kW, voltages up to 1140V. Proven reliability – <1% annual defect rate, 100% full‑load motor testing before delivery. Cost effective – Factory direct pricing: 30‑50% lower than ABB, Siemens, Schneider, Danfoss. Short lead time – 2‑3 weeks for most models (vs. 12‑30 weeks for European brands). Easy replacement – Direct retrofit for ABB PSR/PSTX, Siemens 3RW, Schneider ATS, Danfoss MCD. Global support – Remote commissioning via WhatsApp/TeamViewer, on‑site support via local partners. Certified quality – CE, ISO, CCS (marine), with optional UL/CSA. 11. Call to Action Buy directly from a top 5 soft starters manufacturer in China – save 30‑50% today. �� Request a quote – Send your motor power, voltage, and current soft starter model to [email protected] �� WhatsApp / WeChat – 86 150 1853 9591 �� Website – www.inomaxtechnology.com �� Download datasheet – AST6100 / AST6800 / AST7000 catalog (PDF) �� Get a cross‑reference – Tell us your existing ABB/Siemens/Schneider part number for a one‑to‑one replacement recommendation. Become a distributor – Exclusive territories available. Partner with a leading AC motor soft starter manufacturer for long‑term growth. INOMAX Technology Co., Ltd. – Shenzhen, China Build your trust of technology from China. AST7000  is In-built bypass soft starters ,same technology as Aucom EMX3,DANFOSS and WEG.