Home / Blog / How to safely and conveniently control high-inrush current machinery from a distance
How to safely and conveniently control high-inrush current machinery from a distance
15.06.2026
Modern workshops, sawmills, agricultural farms, and production floors all require solutions that combine two key features: high machinery safety and maximum operator convenience.
When working with high-power three-phase motors (from 5.5 kW / 400 V and above), the primary challenge becomes the so-called inrush current. Simply switching the motor on “all at once” could trip the circuit breakers or overload the grid. This is where the classic, approved Star-Delta (λ-Δ) starter circuit comes to the rescue.
HOW TO SAFELY AND CONVENIENTLY CONTROL HIGH-INRUSH CURRENT MACHINERY FROM A DISTANCE. TAKE A LOOK INSIDE THE WIRELESSLY REMOTE-CONTROLLED TRIPUS Y-D SWITCH.
From problem to solution
Modern workshops, sawmills, agricultural farms, and production floors all require solutions that combine two key features: high machinery safety and maximum operator convenience.
When working with high-power three-phase motors (from 5.5 kW / 400 V and above), the primary challenge becomes the so-called inrush current. Simply switching the motor on “all at once” could trip the circuit breakers or overload the grid. This is where the classic, approved Star-Delta (λ-Δ) starter circuit comes to the rescue.
But what happens when we enhance it with modern wireless technology? Our friendly vlogger-electrician has once again taken a Tripus product to his workbench. This time, he disassembled the advanced Y-D remote motor switch (model 20P3367.07).
Join us on a technical journey inside this device!
See the Equipment in Action
Before we dive into the detailed component analysis, we encourage you to watch the full video. Step by step, it shows the switch being stripped down to its core components, explains the electrical diagram, and demonstrates the operation of the radio remote control.
What’s inside the Housing? Tripus Component Analysis.
The switch is enclosed in a robust, hermetic housing with an IP54 ingress protection rating, which guarantees full protection against workshop dust and splashing water. However, the most interesting part lies beneath the cover. After unscrewing the bolts and looking inside, we see a perfectly engineered industrial system:
Three-contactor system: the heart of the starting automation. They are responsible for sequentially switching the motor windings from the star configuration (smooth start at reduced voltage) to the delta configuration (full operating power).
Electronic time-delay relay (Timer): it precisely measures the time (usually a few seconds) after which the automatic switchover from star to delta occurs, eliminating human error and protecting the electrical installation.
Integrated radio module with antenna: a receiver that works seamlessly with a handy key-fob remote control (channels A and B). It allows sending a wireless START and STOP pulse from a safe distance.
Main switch with lockout and Emergency Stop button (E-STOP): the ergonomic, red emergency button immediately cuts off the power supply in case of danger, complying with health and safety standards.
Built-in overload protection: an adjustable motor circuit breaker (range 7.2 – 10 A) protects the motor windings from burning out if the machine jams or a phase failure occurs.
How Does It Work in Practice? Diagram and control.
The electrical diagram included with the device (which the vlogger analyzes thoroughly in the video) shows that Tripus engineers paid close attention to full logical safety. The contactors are equipped with both mechanical and electrical interlocks – there is no physical possibility of simultaneous star and delta activation, which would cause a short circuit.
Startup procedure via remote control:
Press button A (START) on the remote.
The system automatically engages the main contactor and the star contactor. The motor starts smoothly without causing a sudden voltage drop in the grid.
After the pre-set time elapses, the system automatically and safely switches the power supply to delta. The motor reaches its full rated power.
Press button B (STOP) – the machine comes to a safe stop.
Where Can the Tripus Y-D Remote-Controlled Switch Be Used?
This is an ideal solution wherever the machine operator cannot or should not stand directly next to the control cabinet:
Large band saws and circular log saws: ability to start and stop the cutting process directly from the log feeding position.
Woodchippers and shredders: safe operation from a distance of several meters away from the hazardous material feed zone.
Winches, belt conveyors, and screw feeders: controlling the transmission line from anywhere in the warehouse.
Submersible pumps and industrial fans: convenient activation of peripheral devices without approaching the main distribution board.
FAQ – Frequently Asked Questions
Is the radio remote control safe and resistant to interference? Yes, the Tripus radio module operates on a dedicated, coded frequency band. The signal is stable, and the risk of accidental machine activation by another device has been eliminated.
Can I mount this switch outside the building? The switch features an IP54 protection class, meaning it is resistant to dust and water splashes from any direction. It can work in semi-open environments (e.g., under a canopy), but it is recommended to avoid direct exposure to continuous, heavy precipitation.
What is the maximum current and motor power supported by this specific model? The model with part number 20P3367.07 is dedicated to three-phase motors (400 V) with a maximum power of up to 7.5 kW. The current setting range of the protective circuit breaker is 7.2 to 10 A.
What happens if I press the emergency stop button on the housing while operating the machine via remote control? The E-STOP button (mushroom head) has absolute hardware priority. Pressing it mechanically breaks the contactor control circuit and immediately cuts off the power supply. Until the mushroom button is unlocked (twisted), starting the machine via the remote control will be impossible.
Summary
Combining classic star-delta starting with Tripus wireless radio control is a milestone in the ergonomics of working with heavy-start machinery. You protect your electrical system from overloads, safeguard the motor thanks to the built-in automatic switchover timer, and gain complete freedom of movement as an operator.
Do you have questions about matching the right switch to your machine? Check out the full technical specifications in our Tripus Product Catalog or contact our technical department directly!
Contact form
In case any technical questions our Technical Department remain for Your disposal
In our December post, we demonstrated how Wi-Fi technology in Tripus switches simplifies the management of holiday illuminations. Today, however, we are setting decorations aside to focus on engineering and industrial practice.
The Star-Delta (Y-D) start-up is one of the most popular methods for limiting the inrush current of induction motors. However, what seems simple in theory often causes practical challenges when selecting the right protective equipment. A calculation error can lead to either “nuisance” tripping or, even worse, a burnt-out motor winding.
In our December post, we demonstrated how Wi-Fi technology in Tripus switches simplifies the management of holiday illuminations. Today, however, we are setting decorations aside to focus on engineering and industrial practice.
The Star-Delta (Y-D) start-up is one of the most popular methods for limiting the inrush current of induction motors. However, what seems simple in theory often causes practical challenges when selecting the right protective equipment. A calculation error can lead to either “nuisance” tripping or, even worse, a burnt-out motor winding.
Recently on our LinkedIn profile, we focused extensively on the reliability and versatility of the MS25 series. Your interest in these posts has confirmed our belief that solid drive protection is a critical topic for every modern facility. Continuing this thread, we have prepared a detailed breakdown to help you understand why these devices are […]
