a. รอบต่อนาทีเป็นเท่าใด 6 โพลมอเตอร์?

What is the RPM of a 6 เสามอเตอร์?

ตอบด่วน

A 6-pole AC induction motor has a synchronous speed of 1,200 รอบต่อนาทีที่ 60 เฮิรตซ์ และ 1,000 รอบต่อนาทีที่ 50 เฮิรตซ์, calculated using the formula N_ส - 120 × ฉ / พี. Under actual load, the rotor runs 2–5% slower due to slip, giving a typical full-load speed of 1,140–1,176 RPM at 60 เฮิรตซ์ (or 960–980 RPM at 50 เฮิรตซ์). ต่อ ไม่มีเอ็มจี 1, Design B motors—the most common industrial class—exhibit 2–5% rated slip, while high-efficiency IE3/IE4 motors per ไออีซี 60034-30-1 achieve tighter slip ranges of 1–3%. The exact nameplate RPM depends on motor size, ระดับประสิทธิภาพ, เงื่อนไขการโหลด, and design letter.

What Is a 6-Pole Motor?

A 6-pole motor is a three-phase AC induction motor whose stator winding produces three pairs of magnetic poles (6 total). Magnetic poles always occur in north–south pairs, so motor pole counts are always even numbers: 2, 4, 6, 8, 10, หรือ 12. The number of poles is one of two factors—alongside supply frequency—that determines the motor’s synchronous speed.

ตาม ไออีซี 60034-1 (Rotating Electrical Machines – Rating and Performance), a 6-pole configuration falls into the medium-speed category. ที่ 50 เฮิรตซ์, it delivers a synchronous speed of 1,000 รอบต่อนาที; ที่ 60 เฮิรตซ์, it reaches 1,200 รอบต่อนาที. This makes 6-pole motors ideal for applications requiring moderate rotational speed with higher torque output than the more common 4-pole designs.

For comparison, here is the synchronous speed of common pole configurations at standard frequencies:

แหล่งที่มา: Synchronous speed calculated per NEMA MG 1 และไออีซี 60034-1; full-load speeds reflect typical 2–5% slip for Design B motors.

How a 6-Pole Motor Generates Speed: ทีละขั้นตอน

Understanding why a 6-pole motor runs at 1,200 รอบต่อนาที (หรือ 1,000 รอบต่อนาที) requires following the electromechanical chain from power supply to shaft rotation. Here is the step-by-step process:

ขั้นตอน 1: AC Power Supply Energizes the Stator

Three-phase AC voltage is applied to the stator windings. In a 6-pole motor, the stator has 3 sets of coils per phase (9 coil groups total), arranged so that the magnetic field completes one north–south cycle every 120 electrical degrees per pole pair. ที่ 60 เฮิรตซ์, the AC waveform cycles 60 ครั้งต่อวินาที.

ขั้นตอน 2: Rotating Magnetic Field Forms

The three-phase current, offset by 120 electrical degrees, creates a สนามแม่เหล็กหมุน (เพื่อการเลี้ยงชีพ) in the stator. The speed of this field is the synchronous speed. For a 6-pole motor at 60 เฮิรตซ์, the RMF completes one full revolution every 1/20th of a second (เนื่องจาก 60 Hz ÷ 3 pole pairs = 20 revolutions per second = 1,200 รอบต่อนาที).

ขั้นตอน 3: Rotor Current Is Induced

The rotating field sweeps past the rotor conductors (typically aluminum or copper bars in a squirrel cage). Per Faraday’s law of electromagnetic induction, this relative motion induces a current in the rotor bars. As Yaskawa’s Application Report on Induction Motor Speed Torque Characteristics explains, the induced current magnitude depends on the rate of flux change, which is directly tied to slip frequency.

ขั้นตอน 4: Torque Is Produced

The induced rotor current interacts with the stator’s magnetic field to produce electromagnetic torque (ลอเรนซ์ ฟอร์ซ). This torque accelerates the rotor in the same direction as the rotating field. อย่างไรก็ตาม, the rotor can never reach synchronous speed—if it did, there would be zero relative motion between the field and rotor, zero induced current, and zero torque.

ขั้นตอน 5: Equilibrium at Full-Load Speed

The rotor settles at a speed slightly below synchronous speed, where the torque produced equals the load torque. This speed difference is the ลื่น. For a 6-pole Design B motor at 60 เฮิรตซ์, typical full-load slip is 2–5%, yielding an actual speed of approximately 1,140–1,176 RPM. Higher-efficiency motors (IE3/IE4) tend to have lower slip due to optimized rotor bar geometry and reduced rotor resistance, as confirmed by research published in IEEE Conference Paper DOI: 10.1109/IEMDC.2019.8785212.

Feature Comparison: 6-Pole vs. Other Pole Configurations

Choosing the right pole count is one of the most critical decisions in motor selection. Below is a detailed comparison of 6-pole motors against 2, 4, and 8-pole alternatives across 8 key parameters:

ข้อมูลทางวิศวกรรม: สูตร, ประสิทธิภาพ & ขีดจำกัดอุณหภูมิ

Core Speed and Slip Formulas

The following formulas are essential for any engineer working with 6-pole induction motors. They are derived from the fundamental relationships defined in ไม่มีเอ็มจี 1 และ ไออีซี 60034-1.

1. Synchronous Speed Formula:

เอ็น_ส - (120 × ฉ) / พี

ที่ไหน: เอ็น_ส = synchronous speed (รอบต่อนาที), f = frequency (เฮิรตซ์), P = number of poles

ตัวอย่าง: 6-pole motor at 60 Hz → N_ส - (120 × 60) / 6 - 1,200 รอบต่อนาที

2. Slip Formula:

ส = (เอ็น_ส − N_ร) / เอ็น_ส × 100%

ที่ไหน: s = slip (%), เอ็น_ส = synchronous speed (รอบต่อนาที), เอ็น_ร = actual rotor speed (รอบต่อนาที)

ตัวอย่าง: If N_ส - 1,200 RPM and N_ร - 1,164 RPM → s = (1,200 - 1,164) / 1,200 × 100% - 3%

3. Actual Rotor Speed:

เอ็น_ร = N_ส × (1 − s)

ตัวอย่าง: 6-pole at 60 เฮิรตซ์, 3% slip → N_ร - 1,200 × (1 - 0.03) - 1,164 รอบต่อนาที

4. Torque–Power–Speed Relationship:

ที = (พี × 9,550) / เอ็น_ร

ที่ไหน: T = torque (น.ม), P = power (กิโลวัตต์), เอ็น_ร = rotor speed (รอบต่อนาที)

ตัวอย่าง: 7.5 kW 6-pole motor at 1,164 RPM → T = (7.5 × 9,550) / 1,164 - 61.5 น.ม

5. โรเตอร์ (ลื่น) ความถี่:

ฉ_{โรเตอร์} = s × f_{จัดหา}

ตัวอย่าง: 3% slip at 60 Hz → f_{โรเตอร์} - 0.03 × 60 - 1.8 เฮิรตซ์

6. ไม่มีเอ็มจี 1 ปัจจัยการบริการ:

SF = โหลดพิกัด / Nameplate Power

Standard NEMA service factor is 1.0 หรือ 1.15 for general-purpose motors, meaning a motor can continuously handle up to 15% overload above its nameplate rating under rated conditions.

ไออีซี 60034-30-1 คลาสประสิทธิภาพ

ไออีซี 60034-30-1 standard defines minimum efficiency requirements for single-speed, three-phase induction motors. For a 6-pole motor, the efficiency thresholds vary by output power. The table below shows typical 4-pole equivalent values as a baseline—6-pole motors generally achieve 1–2% lower efficiency at equivalent power due to higher rotor losses and reduced cooling effectiveness at lower speeds.

Efficiency values are indicative for 50 Hz operation. ต่อกรมวิชาการเกษตร 10 ส่วนซีเอฟอาร์ 431, motors sold in the U.S. after June 1, 2027 must meet IE3-equivalent minimums for most ratings. แหล่งที่มา: เรา. กรมพลังงาน.

ไออีซี 60034-1 ขีดจำกัดอุณหภูมิของชั้นฉนวน

Temperature rise directly affects motor life. ตาม IEC 60034-1, insulation classes define the maximum allowable temperature rise. A 6-pole motor typically uses Class F (155องศาเซลเซียส) insulation, operated at Class B (130องศาเซลเซียส) rise for margin:

Siemens SIMOTICS SD 1LE1501 series 6-pole motors (7.5 กิโลวัตต์ที่ 50 เฮิรตซ์) use Class F insulation per IEC 60034-1, with IP55 enclosure and IC411 cooling. แหล่งที่มา: Siemens Product Catalog.

ไม่มีเอ็มจี 1 Design Letters and Slip Characteristics

ไม่มีเอ็มจี 1 defines four design letters that classify squirrel-cage induction motors by their torque–speed characteristics. These directly affect the actual running speed of a 6-pole motor:

Design B dominates industrial use, balancing efficient full-load running with adequate starting torque. แหล่งที่มา: ไม่มีเอ็มจี 1-2021; ไออีซี 60034-12.

Best Applications for 6-Pole Motors

The 6-pole motor’s characteristic medium speed (1,200 รอบต่อนาทีที่ 60 เฮิรตซ์) and higher torque density make it the preferred choice for applications where a 4-pole motor (1,800 รอบต่อนาที) would require excessive gearing, and an 8-pole motor (900 รอบต่อนาที) would be physically oversized. Common applications include:

1. Conveyor Systems and Material Handling

Conveyors typically operate at belt speeds of 0.5–2.0 m/s, requiring output shaft speeds in the 1,000–1,200 RPM range before speed reduction. A 6-pole motor’s 1,140–1,176 RPM full-load speed reduces the required gearbox ratio, improving system efficiency and reducing maintenance. NEMA Design C 6-pole motors are often specified here for their high starting torque (~200% rated), as documented in gear motor selection guides.

2. Industrial Mixers and Agitators

Mixing applications in chemical processing, food production, and water treatment require consistent torque at moderate speeds. A 6-pole มอเตอร์แบบอะซิงโครนัสสามเฟส provides the torque margin needed for viscous or variable-density loads without the complexity of variable-speed drives.

3. Compressors and Positive Displacement Pumps

Reciprocating compressors and screw compressors benefit from the 6-pole motor’s lower operating speed, which reduces mechanical stress on crankshafts and bearings. เดอะ air compressor motor application often specifies 6-pole designs for units in the 5.5–15 kW range, where the combination of 1,000–1,200 RPM and high torque matches compressor load curves directly.

4. HVAC Fans and Blowers

Large industrial ventilation fans and centrifugal blowers often have impeller designs optimized for 1,000–1,200 RPM input speed. Using a 6-pole motor eliminates the need for belt-and-pulley speed reduction, cutting maintenance and improving reliability. สำหรับ smaller fan applications, 4-pole or 6-pole shaded-pole motors are common.

5. Electric Vehicles and Traction Drives

Research published in IEEE IEMDC 2019 (ดอย: 10.1109/IEMDC.2019.8785212) demonstrates that variable-pole induction machines using 6-pole configurations at low speeds deliver significantly higher torque capability for EV gradeability and acceleration. At cruising speeds, switching to a lower pole count extends the high-efficiency operating range—an approach validated experimentally with average loss reduction of one-third at partial loading.

Step-by-Step Selection Guide for 6-Pole Motors

Selecting the right 6-pole motor involves matching speed, แรงบิด, ประสิทธิภาพ, and environmental requirements. Follow this 6-step process:

ขั้นตอน 1: Define Load Speed and Torque Requirements

Determine the required output shaft speed and torque for your driven equipment. If the load operates at 1,000–1,200 RPM, a 6-pole motor may drive it directly without a gearbox. For lower output speeds, calculate the required gear ratio: Gear Ratio = Motor RPM / Output RPM. ตัวอย่างเช่น, ก motor with gearbox running at 1,164 รอบต่อนาทีด้วย 10:1 ratio delivers 116 เอาท์พุทรอบต่อนาที.

ขั้นตอน 2: Calculate Required Motor Power

Use the formula P = T × N_ร / 9,550 (kW = N·m × RPM / 9,550). Add a 15–25% service factor for variable loads. Cross-check against standard motor ratings: 6-pole motors are commonly available in 0.75 กิโลวัตต์, 1.5 กิโลวัตต์, 2.2 กิโลวัตต์, 3.7 กิโลวัตต์, 5.5 กิโลวัตต์, 7.5 กิโลวัตต์, 11 กิโลวัตต์, 15 กิโลวัตต์, 18.5 กิโลวัตต์, 22 กิโลวัตต์, และ 30 กิโลวัตต์ที่ 50 เฮิรตซ์.

ขั้นตอน 3: Verify Frequency and Voltage Compatibility

A 6-pole motor designed for 50 เฮิรตซ์ (1,000 RPM synchronous) will run at 5/6 ความเร็ว (833 RPM synchronous) on a 60 Hz supply if voltage is adjusted proportionally. ในทางกลับกัน, ก 60 Hz motor (1,200 รอบต่อนาที) on 50 Hz will run slower but may overheat if voltage is not derated. Always verify the nameplate frequency rating. For dual-frequency operation, consult the manufacturer’s derating curve per IEC 60034-1.

ขั้นตอน 4: Select Efficiency Class Based on Regulatory Requirements

Per the เรา. กรมวิชาการเกษตร 10 ส่วนซีเอฟอาร์ 431, most general-purpose motors (1–500 HP) sold in the United States must meet IE3 (ประสิทธิภาพระดับพรีเมี่ยม) minimums. The compliance date for expanded standards covering 100–750 HP motors is มิถุนายน 1, 2027. In the EU, Regulation 2019/1781 requires IE3 from July 1, 2021 for motors rated 75–375 kW, and IE4 from July 1, 2023 for 75–200 kW. Selecting an IE3 or IE4 motor not only ensures compliance but also reduces slip, bringing actual speed closer to synchronous.

ขั้นตอน 5: Choose NEMA Design Letter

Select the design letter based on your load’s starting characteristics:

• ดีไซน์ บี (2–5% slip): Choose for centrifugal pumps, แฟน ๆ, and general-purpose applications with low starting inertia.
• Design C (~5% slip): Choose for loaded conveyors, reciprocating compressors, and high-inertia starts.
• Design D (5–13% slip): Choose for punch presses, รถเครน, and applications requiring energy absorption through slip.

ขั้นตอน 6: Verify Bearing Life and Thermal Margin

Calculate bearing L10h life per SKF bearing rating life methodology: L10ชม. = (10⁶ / 60n) × (ซี/พี)^พี, where C is the dynamic load rating, P is the equivalent bearing load, n is the rotational speed, and p = 3 สำหรับลูกปืนหรือ 10/3 สำหรับแบริ่งลูกกลิ้ง. A 6-pole motor at 1,164 RPM generates lower bearing loads than a 4-pole at 1,750 รอบต่อนาที, typically extending L10h life by 20–30% for the same bearing size. Verify that the insulation class provides adequate thermal margin: for ambient temperatures above 40°C, derate per IEC 60034-1 guidelines.

Common Engineering Mistakes When Working with 6-Pole Motors

ความผิดพลาด 1: Confusing Synchronous Speed with Nameplate Speed

Many engineers reference 1,200 RPM as the speed of a 6-pole motor at 60 เฮิรตซ์, but this is the synchronous ความเร็ว. The actual nameplate (full-load) speed is typically 1,140–1,176 RPM. Designing a system around 1,200 RPM without accounting for slip leads to undersized gear ratios and incorrect output speed calculations.

ความผิดพลาด 2: Ignoring Frequency Mismatch Between 50 เฮิรตซ์และ 60 เฮิรตซ์

Installing a 50 Hz-rated 6-pole motor (synchronous 1,000 รอบต่อนาที) on a 60 อุปทานเฮิร์ตซ์ (synchronous 1,200 รอบต่อนาที) increases speed by 20% and can cause over-fluxing, ความร้อนสูงเกินไป, and insulation degradation if the voltage is not adjusted proportionally. Always verify that the motor is rated for the operating frequency, or use a VFD to control the frequency.

ความผิดพลาด 3: Selecting the Wrong NEMA Design Letter

Using a Design B motor (150% แรงบิดเริ่มต้น) on a loaded conveyor that requires Design C (200% แรงบิดเริ่มต้น) will cause starting failures and potential motor burnout. ในทางกลับกัน, using a Design D motor (5–13% slip) on a centrifugal pump wastes energy through excessive slip losses. Research by Libbos et al. ใน IEEE Transactions on Transportation Electrification (ดอย: 10.1109/TTE.2020.2997692) shows that pole-count and design selection errors can reduce system efficiency by up to 30% at partial loading.

ความผิดพลาด 4: Overlooking Efficiency Class Impact on Slip

IE3 and IE4 motors have lower rotor resistance to reduce I²R losses, which also reduces slip. An IE3 6-pole motor might run at 1,176 รอบต่อนาที (2% ลื่น) while an IE1 equivalent runs at 1,140 รอบต่อนาที (5% ลื่น). นี้ 36 RPM difference can affect pump flow rates and conveyor speeds in precision applications. Always design around the nameplate speed of the specific efficiency class being installed.

ความผิดพลาด 5: Neglecting Slip-Induced Rotor Heating

Slip is not just a speed indicator—it directly measures energy dissipated as rotor heat. Per the relationship P_{rotor loss} = s × P_air-gap, a motor at 5% slip dissipates 5% of its air-gap power as rotor I²R heating. In high-ambient environments or with frequent starts, this can push winding temperatures beyond insulation limits. A study on slot-pole combinations published in IEEE ELECO 2023 (ดอย: 10.1109/ELECO60389.2023.10416013) demonstrates that improper pole-slot combinations amplify torque harmonics, further increasing thermal stress.

ความผิดพลาด 6: Underestimating the Effect of Voltage Unbalance on Slip

A voltage unbalance as small as 2% can increase slip by 10–15% and raise operating temperature by 10–15°C. ไม่มีเอ็มจี 1 recommends derating motor output by approximately 5% for every 1% voltage unbalance. In a 6-pole motor already operating near its thermal limit, this can significantly shorten bearing and insulation life.

ตารางการแก้ไขปัญหา: 6-Pole Motor Speed Issues

คำถามที่พบบ่อย

1. What is the RPM of a 6 pole motor at 60 เฮิรตซ์?

A 6-pole motor at 60 Hz has a synchronous speed of 1,200 รอบต่อนาที. Under full load, the actual running speed is typically 1,140–1,176 RPM, depending on the NEMA design letter and efficiency class. Standard Design B motors run at approximately 1,140–1,170 RPM (2–5% slip).

2. What is the RPM of a 6 pole motor at 50 เฮิรตซ์?

A 6-pole motor at 50 Hz has a synchronous speed of 1,000 รอบต่อนาที. Under full load, the actual running speed is typically 960–980 RPM with 2–4% slip. High-efficiency IE3/IE4 motors tend to run closer to 980 RPM due to lower slip.

3. How do you calculate the RPM of a 6 โพลมอเตอร์?

ใช้สูตร เอ็น_ส - (120 × ฉ) / พี, where N_ส คือความเร็วซิงโครนัสในหน่วย RPM, f คือความถี่ในหน่วย Hz, and P is the number of poles. For a 6-pole motor at 60 เฮิรตซ์: เอ็น_ส - (120 × 60) / 6 - 1,200 รอบต่อนาที. To find actual speed, apply slip: เอ็น_ร = N_ส × (1 − s), where s is the slip percentage (typically 0.02–0.05 for Design B motors).

4. Why does a 6 pole motor run slower than a 4 โพลมอเตอร์?

Motor speed is inversely proportional to the number of poles. More poles mean the rotating magnetic field completes fewer revolutions per cycle. ก 4-pole motor at 60 เฮิรตซ์ has a synchronous speed of 1,800 รอบต่อนาที, while a 6-pole motor at 60 Hz has a synchronous speed of only 1,200 รอบต่อนาที. The trade-off is that 6-pole motors deliver higher torque at the same power rating, following the relationship T = P × 9,550 / เอ็น.

5. Can I run a 50 เฮิรตซ์ 6 pole motor on a 60 อุปทานเฮิร์ตซ์?

ใช่, but the motor will run 20% เร็วขึ้น (from ~960 RPM to ~1,152 RPM). If the voltage is increased proportionally (โดย 20%), the motor can operate safely at the higher frequency. อย่างไรก็ตาม, if voltage is not adjusted, the motor may over-flux and overheat. Always consult the manufacturer’s nameplate and derating guidelines per IEC 60034-1.

6. What is the difference between synchronous speed and full-load speed for a 6 โพลมอเตอร์?

ความเร็วแบบซิงโครนัส (1,200 รอบต่อนาทีที่ 60 เฮิรตซ์) is the speed of the rotating magnetic field. Full-load speed (typically 1,140–1,176 RPM) is the actual rotor speed under rated load. The difference is called ลื่น, expressed as a percentage. Slip is necessary for torque production in มอเตอร์เหนี่ยวนำ—without it, no current would be induced in the rotor and no torque would be produced.

Why Choose Greensky?

When sourcing a 6-pole motor for your application, บริษัท กรีนสกี้ พาวเวอร์, จำกัด. offers distinct advantages that go beyond standard manufacturing:

• Engineering-Driven Approach: ร.ของเรา&ทีมงานดี 8 PhD-level engineers reinvests 10% of annual revenue into research, ensuring that every motor design is optimized for the specific speed, แรงบิด, and efficiency requirements of your application—including precise 6-pole winding configurations.
• IE3/IE4 Compliance: ของเรา squirrel cage asynchronous motors meet or exceed IEC 60034-30-1 IE3 efficiency requirements, ensuring compliance with DOE 10 ส่วนซีเอฟอาร์ 431 regulations effective June 1, 2027 for the U.S. ตลาด.
• 100% Factory Testing: Every motor undergoes individual performance testing on dynamometers, including full-load speed verification, slip measurement, and temperature rise validation per IEC 60034-1.
• Customization Capability: We offer custom shaft dimensions, การกำหนดค่าการติดตั้ง (B3, บี5, B14, B35 per IEC 60034-7), voltage ratings (230V/400V/460V), and frequency options (50/60 Hz dual-rated) to match your specific installation requirements.
• Global Standards Compliance: All motors are manufactured under ISO 9001 การจัดการคุณภาพ, with CE, ซี.ซี.ซี, และการรับรองประสิทธิภาพการใช้พลังงาน. ของเรา gearbox solutions are available with NEMA and IEC frame compatibility.
• North American Local Support: Through our subsidiary United Motion Inc., we provide pre-sales consultation, ความช่วยเหลือในการทดสอบตัวอย่าง, and after-sales warranty support for customers in the United States and Canada—reducing sourcing risk and response time.

For projects requiring 6-pole motor solutions, three-phase motor configurations, หรือ custom motor selection, contact our engineering team for a free technical consultation and quotation.

รับใบเสนอราคาฟรี

อ้างอิง

1. ไออีซี 60034-1:2022 — Rotating Electrical Machines – Part 1: Rating and Performance. https://webstore.iec.ch/publication/60661
2. ไออีซี 60034-30-1:2020 — Rotating Electrical Machines – Part 30-1: Efficiency Classes of Line Operated AC Motors. https://webstore.iec.ch/publication/60759
3. ไม่มีเอ็มจี 1-2021 – มอเตอร์และเครื่องกำเนิดไฟฟ้า. สมาคมผู้ผลิตไฟฟ้าแห่งชาติ. https://www.nema.org/standards/view/ANSI-NEMA-MG-1
4. เรา. Department of Energy — Energy Conservation Standards for Electric Motors, 10 ส่วนซีเอฟอาร์ 431. https://www.energy.gov/cmei/buildings/small-electric-motors
5. Libbos, E., และคณะ. — “Variable-Pole Induction Machine Drive for Electric Vehicles,” IEEE IEMDC 2019. ดอย: 10.1109/IEMDC.2019.8785212
6. Libbos, E., และคณะ. — “Loss Minimization and Maximum Torque-Per-Ampere Operation for Variable-Pole Induction Machines,” IEEE Transactions on Transportation Electrification, 2020. ดอย: 10.1109/TTE.2020.2997692
7. Koçak, F., และคณะ. — “High Frequency Induction Motor Design with the Examination of Slot/Pole Combinations,” IEEE ELECO 2023. ดอย: 10.1109/ELECO60389.2023.10416013
8. SKF — Bearing Rating Life Calculation, กอ.รมน 281 Methodology. https://www.skf.com/africa/en/products/bearings-units-housings/principles/bearing-selection-process/bearing-size/size-selection-based-on-rating-life/bearing-rating-life/
9. Siemens — SIMOTICS SD 1LE1501 Series 6-Pole Motor Technical Data. https://mall.industry.siemens.com/mall/zh/cn/Catalog/Product/?mlfb=1LE1501-1CC6.-….
10. Yaskawa America — Induction Motor Speed Torque Characteristics, Application Report AR.MOTOR.01. https://www.yaskawa.com/downloads/-/document/downloads?productGroup=Inverter%20Drives&productLine=AC%20Motors