Everything you need to know about the function, selection, and application of reversing switches for three-phase motors.
What is the main function of a three-phase reversing switch?
A three-phase reversing switch primarily serves to reverse the direction of rotation of a three-phase motor. This is done by swapping two phases of the power supply, which changes the motor’s rotating field direction.
What should I pay attention to when selecting a reversing switch for my three-phase motor?
Pay attention to the rated voltage (e.g., 400V), the rated current (A) suitable for the motor power (kW), the switching capacity (especially AC-3 for motors), the protection class (IP protection) according to the environment, and the design. Certifications like TÜV are a quality feature.
What typical errors can occur when connecting a three-phase reversing switch?
Common errors include a wrong phase assignment, which leads to an undesired direction of rotation, loose terminal connections, which can cause overheating, and the use of unsuitable cable cross-sections. A thorough check of the connection plan and the connections is essential.
Is a separate motor protection switch necessary when using a reversing switch?
Yes, in most cases. A reversing switch typically provides no overload or short circuit protection for the motor. The combination with an appropriate motor protection switch is highly recommended to prevent motor damage. Some systems offer integrated protection.
Can reversing switches increase efficiency in industrial plants?
Yes, by enabling quick direction reversal, reversing switches can optimize process flows. For example, the handling speed of cranes can be increased by up to 10% or the productivity of CNC machines can be increased by 10-15% .
What role do standards and test marks play in three-phase reversing switches?
Standards (e.g. EN 60947) and test marks (e.g. CE, TÜV) confirm adherence to fundamental safety and quality standards. This is especially important for the operational safety and reliability of the system.
Are there reversing switches with additional features?
Yes, many reversing switch systems offer additional features such as integrated emergency stop buttons, under-voltage triggers (prevent uncontrolled restarting), CEE connectors for easy connections or are available as star-delta switches with reversing function .
What do I do if the motor runs in the wrong direction after connecting the reversing switch?
If the motor runs in the wrong direction, you need to swap two of the three supply phases (line conductors) at the input of the reversing switch. Make sure to disconnect the system from the power supply first! A check with a rotating field measuring device beforehand can prevent this.
Three-phase reversing switches are essential for the reversal of motor rotation direction, which can increase the productivity by 10-15% in applications such as machine tools and conveyor systems. The correct selection is based on
motor power, voltage, current (AC-3), and IP protection class Motorleistung, Spannung, Strom (AC-3) und IP-Schutzart; careful installation and adherence to connection plans are crucial for the operational safety. For optimal protection and functionality,.
reversing switches should be combined with motor protection switches and compliance with certifications (e.g. TÜV) as well as standard conformity should be considered to maximize the geachtet werden, um die system reliability..Learn how to enhance the performance and flexibility of your machines with the right three-phase reversing switch. This article provides you with the necessary know-how!
Do you want to change the rotation direction of your three-phase motors easily and safely? Three-phase reversing switches are the solution! They allow for straightforward control and are an indispensable element in many industrial applications. Contact us for individual advice and find the optimal reversing switch for your requirements: Get in touch now!Do you need assistance in selecting the appropriate three-phase reversing switch for your application?
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Understand: Basics and typical applications of three-phase reversing switches master
Ein Three-phase reversing switches reverses the rotation direction of three-phase motors by swapping two network phases. This reversal of the magnetic rotating field in the motor allows, e.g., a crane to lift/lower loads precisely and increase the handling speed by up to 10%. This also resolves material jams in conveyor systems.
Over 75% of machine tools use such directional reversing switches for direction changes, e.g., turning machines, milling machines, conveyor systems, pumps, gate drives. Their versatility supports flexible production processes; reversible conveyor systems in the food industry can thus reduce cleaning times by 20%.
For reliable operation in harsh environments, a suitable IP protection class, such as IP65 (protection against dust/water jets), is important. Correct installation according to VDE regulations, especially with a reversing switch rated at 400V, prevents personal injury and property damage. ATEK Drive Solutions takes this into account in drive train designs.Selecting: Technical specifications and criteria for Three-phase reversing switches precisely determining
A wrongly dimensioned Three-phase reversing switches can lead to issues such as frequently tripping motor protection. The selection starts with voltage and current. To avoid overload, the rated power (kW) and rated current (A) of the motor must be considered. A KEDU ZH-A switch is, for example, specified for 10(6)A at 400V, with (6)A indicating the switching capacity for inductive motor loads (AC-3).
Three-phase reversing switches are available in various designs: surface-mounted switches for direct mounting, built-in switches for control panels, or in robust housings (ISO, cast housings). The choice of design depends on environmental conditions and available space. Klinger & Born offers a selection of simple reversing switches to complex control device combinations.
Other selection criteria include maximum switching capacity, voltage range (e.g., 230V, 400V), and number of poles (usually 3-pole for three-phase motors). Certifications like TÜV signal tested quality. A suitable Motor left-right switch ensures the operational safety of the system.Connecting: Three-phase reversing switches install securely and avoid common errors
A wrongly connected Three-phase reversing switches can cause motor damage and hazardous situations. First, disconnect the system from the power supply and ensure it is secured against reactivation. Before laying the lines (L1, L2, L3 to the network; U, V, W to the motor), the connection plan of the switch should be carefully checked. A multimeter is used to check all connections before commissioning.
- Disconnect and secure the system before working.
- Connection plan of the three-phase reversing switch should be studied carefully.
- Ensure correct assignment of the network (L1, L2, L3) and motor leads (U, V, W).
- Check all connections with a multimeter before commissioning.
- Pay attention to solid terminal connections to avoid overheating and fire hazards.
- Use correct cable cross-sections and observe limitations when using ferrules, if necessary.
- Check initial rotating field direction and, if necessary, correct it by swapping two network phases at the input of the reversing switch. Typical sources of errors are swapped phases or loose terminal connections.
Loose connections cause high contact resistances, overheating, and fire hazards. Correct cable cross-sections are also important; for some switches, the cable cross-section is restricted to 1.5mm² when using ferrules, an important aspect for the reliable operation of a Korrekte Kabelquerschnitte sind ebenfalls wichtig; bei manchen Schaltern ist der Kabelquerschnitt bei Nutzung von Aderendhülsen auf 1,5mm² begrenzt, ein wichtiger Aspekt für den zuverlässigen Betrieb eines three-phase reversing switch..
The direction of the network’s rotating field determines the initial motor direction of rotation. If this does not match, two line conductors at the network input of the three-phase reversing switch must be swapped to achieve correct forward/reverse operation. A check with a rotating field measuring device before motor connection is advisable.Compare: Manufacturers, products, and prices of three-phase reversing switches evaluate transparently.
Well-known manufacturers of three-phase reversing switches like Eaton (Moeller ® Series), Klinger & Born, KEDU, Lovato, and Elektra Tailfingen offer a wide range of products. Each manufacturer has specific strengths, such as in price-performance ratio or in special solutions for the industry. ATEK Drive Solutions prioritizes quality and reliability in components for system solutions with gear boxes. Simple
for small motors (e.g., KEDU ZH-A) are available from around 9 Euros. Three-phase reversing switches However, prices vary significantly with switching capacity (e.g., 6.5kW to 37kW), IP protection class, and additional features. An Eaton T0-3-8401/E (6.5kW, 400V) costs about 40 Euros. A pure price comparison is often not sufficient. The choice should not depend solely on price.
Recognized test marks such as TÜV or VDE signal tested quality and protect against inferior products. Providers like sys2sell for KEDU emphasize TÜV certifications as a distinction from questionable KJD/KOA types. Reliability and safety are more important than short-term savings. Integrate: Motor protection and additional features into
Integrieren: Motorschutz und Zusatzfunktionen in Three-phase reversing switches-systems optimally.
Ein Three-phase reversing switches Simply having a reversing switch often does not protect a three-phase motor from overload or short circuit. Therefore, combining it with a suitable motor protection switch is advisable to avoid failures and repairs. Some manufacturers, such as Klinger & Born, offer motor connection units with integrated motor protection (e.g., fixed trip values of 7.0A or 9A).
- Recognize that a Three-phase reversing switches single solution often does not provide sufficient motor protection.
- Combine the reversing switch with a suitable motor protection switch to avoid damage.
- Check options for motor connection units with integrated motor protection already included.
- Utilize additional features such as emergency stop buttons or undervoltage triggers to enhance system safety.
- Consider integrated CEE connectors for increased ease of operation.
- Ensure compliance with relevant standards (e.g., EN 60947) and the presence of certification marks (CE, TÜV).
Modern control systems offer additional functionalities beyond direction reversal: emergency stop buttons, undervoltage triggers (prevent uncontrolled restart after power failure), or integrated CEE connectors. Such extensions enhance system safety and operating comfort. Ein star-delta switches with reversing function is a combination solution for larger motors.
Compliance with standards (e.g., EN 60947) and certification marks (CE, TÜV) for three-phase reversing switches and accessories is essential for safe operation. This confirms the fulfillment of fundamental safety requirements, especially in complex systems such as a motor with frequency converter.Apply: Practical examples and use cases for Three-phase reversing switches successfully implement
In CNC lathes that produce workpieces with right and left threads, such reversing switches enable the quick, precise change of spindle rotation direction. This optimizes machining cycles and can increase productivity by 10-15%, which is important for efficient thread processing.
In logistics centers with long conveyor belts, Three-phase reversing switches in case of blockages allow for the quick reversing of affected belt sections. This promptly eliminates disruptions, maintains material flow, and reduces downtime of sorting systems, which ensures system efficiency.
Pumps or fans may also require direction reversal in certain industrial processes. For example, in pumps, the rotation direction is briefly reversed to clear pipe blockages or to change the flow direction. A robust three-phase reversing switch. is necessary for this. ATEK Drive Solutions supports you in component selection for your specific application case of a reversing switch three-phase.
