Schleich Test Technologies

Everything you always wanted to know about surge voltage testing.

The surge voltage test, also known as the "surge test", is one of the most important and meaningful test methods of all for reliably detecting problems in windings. It mercilessly uncovers a large number of insulation, material and production faults.

Why is surge voltage testing so important?

Electric motors, generators, rotors, stators, transformers, valve coils, sensor coils, coiled goods of all kinds...
These can only be operated safely and for a long time if they have high electrical insulation strength, good material quality and flawless manufacture. Poor insulation quickly leads to total failure.

With the surge voltage test, you determine the  quality of the winding  and  the insulation system  inside  the winding .

SCHLEICH supplies test devices from 1,000 to 50,000 V based on the extensive portfolio in order to cover almost all areas of testing coiled goods with the surge voltage test!

The impulse voltage test cannot replace all known test methods. Therefore, in most cases, a testing device/testing machine consists of a combination of different testing methods.
However, the starting point is always the surge voltage test.

Where is the test object tested?

The surge voltage test is the  "deep look into the winding" .

• within the winding from turn to turn
• from coil to coil
• from phase to phase
• from winding to laminated core

Does this also work with a high-voltage test?

No. Such a depth of testing cannot be achieved either with the high-voltage test or with test methods such as the ohmic resistance test or the inductance test.

What errors does the surge voltage test reveal?

• Insulation distances too small
• insulation weaknesses
• Poor dielectric strength
• wrong number of turns
• different winding geometry
• Enamelled copper wire fault
• interturn shorts
• voltage-dependent interturn faults
• phase shorts
• voltage dependent phase shorts
• body closures
• tension-dependent body closures
• Conclusions of the law
• voltage-dependent layer closures
• Problems with the laminated core
• Problems with the magnetic core
• circuit error
• and more …

How does the surge voltage work technically?

In principle, the surge voltage tester generates a high-voltage pulse with a very high edge steepness.

To do this, it charges the surge capacitor integrated in the test device to the desired voltage level. As soon as the test voltage is reached, the test device switches the charged capacitor to the winding to be tested via a very fast semiconductor switch.
This results in an oscillating circuit consisting of the inductance of the test object and the charged capacitor. The impulse response on the oscillating circuit is a very steep increase in voltage followed by the typical voltage curve in the form of a damped oscillation.
Due to the very rapid voltage jump, high voltage differences are generated between individual and/or multiple turns within the winding.
If there are insulation weaknesses, the short-term high voltage difference leads to discharges. These affect the voltage curve of the damped oscillation in such a way that it visually deviates from an intact winding.
With the help of an analysis method patented by SCHLEICH and various algorithms, the test device analyzes the difference between good and bad voltage and current curves. Based on the analyses, the testing device decides fully automatically whether a winding is OK  (OK) or not OK  (NOK).

How is the surge voltage test performed?

Whether manual, partially or fully automatic: with surge voltage testers from SCHLEICH, every test task can be carried out quickly and efficiently.

Our testing devices are all designed according to the "KISS principle". So according to the motto:  " Keep It Simple and Smart " . The principle is the leitmotif for all SCHLEICH products.

A manual test is carried out by connecting Kelvin clamps to the test object.

Partially or fully automated surge voltage test devices or automatic surge voltage testers are more suitable for the requirements of production companies. For this purpose, the test devices are equipped with a relay switch panel (relay matrix). These automatically switch the surge voltage to the desired test points.

Depending on the application, test systems of this type have up to 100 test connections.

What safety measures does the surge voltage test require?

Working with surge voltage is not without risk. It is therefore essential to comply with the relevant safety regulations and measures to protect against accidental contact.

In the R&D area and in repairs, working on an open, unprotected test object without mandatory contact protection is often unavoidable.
Protective measures such as test hoods, test cabins, light curtains or barrier chains are typically used in production.

Requirements for a standard surge voltage tester?

SCHLEICH surge voltage testers typically have the following features:

• standard test
• high voltage gradient
• very fast measurement technology with high resolution
• Fully automatic switching between the different winding connections of the test object
• fully automatic analysis
• patented evaluation method
• integrated test plan and test result memory
• Development, production and service - Made in Germany

SCHLEICH surge voltage testers are based on more than 30 years of experience and pioneering work. From the beginning, the measurement technology was not analogue, but always digital. In principle, the latest technologies are always used.

How do you find the right surge voltage tester?

If you only want to carry out surge voltage tests on your test object, you are well advised to use a single test device. It includes the surge voltage test and always the insulation resistance test and PI measurement at no extra cost.

If the test object also requires further tests, we recommend our combination test devices/multifunction testers. Additional test methods such as partial discharge, AC high-voltage test – plus partial discharge if required, ohmic resistance test, rotary field test and other functions can be integrated here. The fully automatic test method switchover ensures that no measuring lines on the test object have to be reconnected manually during the test.
Thanks to the intuitive and convenient operation of our surge voltage testers, each test is carried out quickly, precisely and cost-effectively.

The SCHLEICH product portfolio

• Test voltage from 1,000 V up to 50,000 V
• Expandable with the partial discharge test and any additional test method required
• Standardized interfaces such as RS 232, Ethernet / LAN, USB for PC communication
• 24 V digital I/O for PLC communication
• Expandable to Industrial Ethernet and fieldbus systems for PLC communication
• Almost unlimited storage space for test plans and test results
• All parameters determined via the software

In addition, we are happy to plan, design and produce individually tailored solutions for you:

• Single tester, combination tester, multifunction tester
• Test machines/test systems with relay matrix (2, 3, 4, 6, 9, 12, 15, 18, 21 … 100 terminals)
• Complete testing workstations
• Production lines with transfer systems
• EOL Jobs
• large plants

When selecting your surge voltage tester, also pay attention to the “soft skills” of the provider. We offer all the necessary accessories and accompany you throughout the service life of your surge voltage tester:

• Professional advice with technical know-how
• Careful initial start-up
• Regular certified calibration
• After-sales support from our service team
• Service on the phone or on site
• Tailored training
  

SCHLEICH - the world's only provider of protective conductor test devices that has already been awarded the "TOP100 Innovator" seal of quality four times.