Before & After: Electric Motor Maintenance
Workshop Feature

At Valiadis S.A., we continually invest in technologies that enhance the quality and precision of our work. One of the most effective tools we’ve added to our workshop is ultrasonic cleaning—a process that uses high-frequency sound waves to generate microscopic bubbles in a cleaning solution. When these bubbles collapse, they dislodge dirt, grease, and residues from even the most intricate surfaces, without damaging the underlying material.

This advanced method is now fully integrated into our daily maintenance and refurbishment workflow, ensuring that each component is treated with maximum care and technical efficiency.

The images shown here demonstrate a recent example involving a low-voltage electric motor:

• Background: The motor immediately after undergoing ultrasonic cleaning.

• Foreground: The same motor, fully refurbished and ready for delivery.

At Valiadis S.A., we go beyond standard repair. Our approach blends engineering precision with attention to detail, so that every motor we return is not only functional, but also clean, reliable, and ready to perform at its best.

Refurbished & Revitalized
Maintenance Project Update

Some machines earn their legacy through years of dependable operation. These electric motors, originally delivered in 2007 as part of a major irrigation project in combination with KSB pumps, recently returned to us after nearly two decades of continuous service.

They came in for a scheduled overhaul and bearing replacement—a preventative measure to ensure longevity and optimal performance.

We carried out a full technical inspection, followed by a complete restoration. Our Maintenance Department handled every aspect of the process with care and precision, ensuring all work met the highest standards of quality. Now fully refurbished, these motors are ready to go back into service and continue powering vital irrigation systems for years to come.

Refurbished, revitalized, and set to power many more irrigation seasons to come.

PAD Mounted Motors
Product Highlight

Built for tight spaces and tough conditions.
PAD mounted motors are a smart solution when standard frames don’t fit the layout. Designed without feet (footless configuration), these motors are ideal for ventilation, exhaust, and smoke extraction systems, especially where space is at a premium and performance is non-negotiable.

Their TEAO (IC418) cooling design keeps temperatures under control even under heavy use, making them suitable for harsh environments and emergency scenarios. When installed in smoke extraction systems, they support critical safety performance—helping to maintain visibility and clear evacuation routes during fire events.

Available in IEC sizes 71–355, these motors feature:

• Compact PAD (footless) mounting

• Solid corrosion resistance

• Custom insulation classes and protection levels

• Reliable operation under continuous thermal stress

Engineered for resilience. Ready for whatever the system throws at them.

Winch-Ready Power Below Deck
Marine Brake Motor + Planetary Gearbox System for Naval Application

A planetary gearbox, size 310M, has been expertly paired with a 30 kW marine brake motor to form a powerful drive system tailored for winch applications. Built to deliver high torque with smooth, controlled operation across the entire speed range, this unit is designed for safe and reliable lifting and pulling under demanding conditions.

The system is headed overseas for installation below deck on a naval vessel, where tight spaces and uncompromising performance demand nothing but precision engineering.

To ensure accurate control and full compliance with marine standards, the motor-gearbox system is coupled with a marine-certified LS drive—enabling responsive operation even in harsh maritime environments.

Highlights:

• Planetary gearbox – Size 310M

• Marine brake motor – 30 kW

• Marine-certified inverter (LS drive)

• Designed for naval winch operation

• Optimized for tight spaces and critical lifting tasks

Durable. Controlled. Marine-ready.
This is a solution designed not only to perform, but to endure.

Crane Modernization in Steel Plant
Slip Ring Replacement with High-Efficiency AC Motor + AFE Drive

A major overhead crane operating in a steel plant is entering its next chapter. The existing slip ring hoist motor is being replaced with a modern K315L-6 AC motor, paired with an Active Front End (AFE) drive and encoder feedback—offering substantial improvements in performance, safety, and energy recovery.

The upgrade delivers:

• Smoother motion and precise control through vector-based speed regulation

• Higher efficiency and reduced harmonics via AFE drive technology

• Regenerative capability, allowing energy to be fed back to the grid during lowering operations

• Improved power quality, which supports system stability and reduces stress on the electrical infrastructure

Due to tight installation space, the new motor is equipped with a custom axial forced cooling system to ensure optimal thermal management without increasing the motor footprint—making it ideal for enclosed, high-demand environments like steel plants.

Key Specs:

• Motor: K315L-6

• Cooling: Axial forced ventilation system

• Drive system: AFE + Encoder

• Application: Hoisting operation in steel production

This upgrade is a perfect example of next-generation engineering, built to extend equipment life, improve control, and reduce operational costs in a heavy industrial setting.

Custom-Engineered DC Motor for Cable Production Line

While DC motors are being increasingly phased out in favor of AC motor + drive combinations, there are still critical cases where a DC motor is the only viable solution—especially in legacy industrial systems where full redesign isn’t practical.

In this recent case, a customer needed a direct replacement DC motor for a cable production machine, ensuring full compatibility with the existing setup and controls. Using our reverse engineering capabilities, we designed a motor that matched all electrical characteristics, mechanical interfaces, and operational constraints of the original unit.

A custom tachogenerator was integrated into the design to ensure proper speed feedback—preserving the system’s control architecture while upgrading reliability.

Highlights:

• Reverse-engineered DC motor

• Custom-designed tacho integration

• Application: Cable production line

• Purpose: Drop-in replacement, extending machine life

Whether for vintage machinery, critical process continuity, or specialist applications, we continue to support DC motor needs with precision, care, and full engineering backup.

Vertical Legacy, Global Reach
Vertical Hollow Shaft Motors for Deep Well Pumping

Vertical Hollow Shaft (VHS) motors are the driving force behind deep well pumps—especially in regions with demanding irrigation and water supply infrastructure. While commonly used in the United States and Middle East, they are less widespread in Europe. However, Greece holds an exception.

In the 1960s, a pioneering Greek pump factory helped introduce VHS technology to the local market. Valiadis S.A. was a key supplier in that effort, helping establish these motors as a viable and durable solution for deep pumping applications.

Fast forward to today, and we’re proud to continue that legacy—combining historical know-how with modern performance standards. Most recently, we delivered two powerful VHS motors, each rated at:

• 600 HP

• 4 poles

• With a water-cooled upper oil-bearing chamber for enhanced reliability

Designed for vertical mounting and hollow shaft coupling, these motors are built for direct connection to pump lineshafts, ensuring smooth, efficient power transmission with minimal footprint.

Applications:

• Deep well pumping

• Agricultural irrigation systems

• Water supply infrastructure in arid regions

Built for depth. Trusted for decades.

Heat-Proof Precision for Steel Operations
Slip-Ring Motors with Brakes for High-Temperature Environments

We recently delivered three specialized slip-ring motors with brakes, designed specifically for steel industry applications where ambient temperatures can reach up to 70°C.

Operating in such harsh conditions requires more than standard industrial motors. These units were engineered with:

• Class H insulation materials, offering superior thermal resistance

• High-temperature brake component treatments, ensuring consistent braking performance

• Slip-ring design, ideal for high starting torque and controlled acceleration—critical in heavy-duty steel operations

Each motor is tailored for reliability and durability under continuous thermal stress, providing safe, repeatable performance in environments where standard motors would quickly fail.

Key Features:

• Custom thermal design rated for up to 70°C ambient temperature

• Braked slip-ring configuration for dynamic and safe operation

• Application-specific build quality for the steel manufacturing sector

From material handling to process-critical lifting, these motors represent a robust solution in some of the most demanding industrial environments.

Maintenance of High-Voltage Impulse Generator for Insulation Testing

Impulse voltage generators are critical tools in high-voltage laboratories. They produce short-duration, high-energy pulses that mimic natural phenomena such as lightning strikes or switching transients. These pulses are applied to transformers, insulators, cables, and other power system components to verify that their insulation systems meet safety and durability standards.

The generator in question is still actively used in a high-voltage test facility. Its continued performance depends on careful maintenance due to the high stresses involved in impulse generation and the ageing of insulation materials over time.

The scope of our work included:

• Internal inspection and cleaning of the stator windings

• Assessment of insulation condition, including insulation resistance and dielectric absorption testing

• Servicing of excitation systems, bushings, and auxiliary devices

Work was carried out on-site, with special precautions due to the size and configuration of the unit. All measurements were documented, and post-maintenance checks confirmed safe and stable operation.

This project highlights the ongoing need to support legacy test equipment, which continues to play a vital role in the development and certification of power transmission infrastructure.