1900+
rewound stators of industrial motors
250+
customers from 16 countries
93%
work for regular customers
0,12–200kW
power range of electric motors we rewind
More than half of the stators are sent to us by other service companies and spindle manufacturers. We have rewound stators from more than 30 brands, with a stack diameter from under 200 mm to over 350 mm.
We have been rewinding electric motors since 2005. We have refined our knowledge to the point where we offer our winding rewinding service to the largest service companies in Europe. We can even tackle the most complex manual rewinds.
Winding electric motors is a dying trade. Matris is one of the few companies that maintains and develops knowledge further. That’s why we are known as specialists in all kinds of windings. If you are in doubt or do not know if your winding fits into the manageable category, please call or email us with a more detailed description of the problem and the type of motor/winding.
Electric motor rewinding includes:
- incoming winding test,
- removal of the stator core from the housing,
- burning out and cleaning the stator,
- inserting new wire and insulation,
- varnish or epoxy potting to specification,
- curing the varnish or epoxy,
- installing the rewound stator core back into the housing.
What we measure and what you get
Every stator is tested twice on a Schleich MTC-2 system.
The incoming measurement is carried out before we touch the winding. It shows us the condition the stator arrived in, how far it deviates from spec, and whether a rewind is worthwhile. The customer receives the same information.
The outgoing measurement is carried out after rewinding, before the part leaves the workshop. An internal check is also performed before varnishing or epoxy potting, so that any corrections can still be made while they’re simple.
- resistance per phase and deviation between phases
- surge test per phase and comparison between phases
- insulation resistance at 1000 V DC
- Hi-Pot DC up to 2000 V
You receive the incoming and outgoing test report together with the part.
Example from the workshop
Two-speed stator from a Doosan VLC630 vertical turning center, two separate windings in the same stack.
On arrival. Insulation broke down at 138 V with a leakage current of 2.59 mA. The surge comparison between phases failed; one of the three phases showed no inductance at all, indicating a short turn. Resistance between phases, however, was completely fine, with a deviation of 0.24%.
After rewinding. Insulation resistance of 8.47 GΩ at 40°C. The Hi-Pot held 2000 V with a leakage current of 0.11 µA, roughly twenty-three thousand times lower than on arrival. Surge comparison deviation of 3.4% against an allowed 35%. Resistance deviation of 0.58% against an allowed 7%.
Both windings were rewound and tested separately.
Surge Test Before and After Rewinding
On Arrival
| Surge Test | Insulation Resistance | Resistance Deviation |
|---|---|---|
| one phase without inductance | failed at 138 V | 0.24% |
| FAIL | FAIL | PASS |
After Rewinding
| Surge Test | Insulation Resistance | Resistance Deviation |
|---|---|---|
| 3.4% deviation | 8.47 GΩ at 40 °C | 0.58% |
| PASS | PASS | PASS |
In the left image, one phase does not oscillate because the winding is short-circuited, while the other two oscillate normally. On the right, all three curves overlap. The time axes differ because a short-circuited winding oscillates differently. The waveform shape is shown, not the amplitude.
Anyone measuring resistance alone would have declared this winding healthy.
These values apply to this specific part. Limits and expected values vary depending on the winding design, insulation class, and voltage level, so one example cannot be taken as a prediction for another stator. What we do promise is that you’ll see the measured condition both before and after the work.
Warranty and Background Work
We provide a twelve-month warranty on rewinding.
We work in the background. We do not contact your clients, and our name does not need to appear in your documents.
EPOXY-M-HES
A technological process to increase and improve the performance of your electric motor
Many manufacturers of spindle motors encapsulate their windings in epoxy resins to protect them from foreign media ingress (oil, coolants, chemicals), increase efficiency, allow better heat dissipation… Our Epoxy-M-HES system makes the winding more suitable for harsh operating conditions. The system is designed to protect the winding from foreign media ingress, mechanical damage and improper maintenance.
Protection against contamination
Most of the time, the voltage to the housing is broken by water ingress or liquid media. If the winding is protected by being encased in epoxy, it is further protected against external agents.
Extended insulation lifetime
By making the temperature dissipate more quickly, the lifetime of the insulation is extended and the efficiency of the electric motor is increased, as heat losses in iron and copper are reduced.
Resistance to mechanical damage
We have serviced electric motors where the winding has been damaged by a blown bearing. If the winding is mechanically protected with our solution, the chance of damage is reduced.
Brands we rewind
We have rewound stators for over thirty brands. Primarily Siemens, Kessler, Fanuc, Končar, Perske, Baumüller, SEW-Eurodrive, Lenze, Weiss, Mitsubishi, ABB, and Yaskawa, but also Bosch Rexroth, Indramat, Okuma, Leroy Somer, Bonfiglioli, Elte, Giordano Colombo, Emod, Kollmorgen, HSD, GMN, IBAG, Oswald, Setco, Stöber, Jäger, Samag, Parker, and WEG. Stators come from manufacturers, service companies, and end-users. If your brand is not on the list, please send us the data from the nameplate and photos of the winding.
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Visit us
Jelenčeva ulica 1
4000 Kranj
Slovenia
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Working hours
Monday to Friday
from 7. until 15. hours