On-site Electrical Testing
Houghton International provides a range of non-intrusive on-site tests, which can be used to help identify and diagnose early warning signs before they escalate, potentially resulting in total machine failure, unplanned downtime and excess costs.
Planned preventative maintenance (PPM)
We offer periodic offline testing and trending of the machine’s insulation systems to give an overall picture of winding insulation health. Static or offline testing is performed while the machine is not running and can be executed on site or in our electro mechanical repair facility.
We work with customers to agree the most effective schedule based on their needs and the associated risks. A complete diagnosis of the insulation system offered includes winding resistance, meg-ohm, polarization, step-voltage or high potential (Hi-Pot), and surge testing.
- Winding resistance testing can find high-resistance connections that lead to current unbalances and eventual failures.
- The meg-ohm test can determine if the motor is grounded or heavily contaminated by measuring the leakage current through the insulation.
- The polarization test finds old, brittle insulation and deteriorated ground wall insulation.
- The step-voltage or high-potential test further stresses the ground wall insulation, and when performed at the motor control cabinet, it tests the cables as well. Cables should be able to withstand the spiking and voltage levels the motor sees; damaged cables can be a real issue.
- Surge testing allows for the identification of shorted motor conductor turns and failing conductor insulation, which are among the first tell-tale signs of electrical breakdown. The surge test is the only test that can locate weakness within the copper-to-copper insulation, where more than 80% of all winding failures begin.
These tests can be carried out efficiently on site with minimal disruption and the results can then be analysed to make recommendations for future maintenance activity.
Partial Discharge Testing
For higher voltage motors, 6kV and above, Partial Discharge testing can also be used to provide a wider picture of the machine health. High voltage equipment often suffers from Partial Discharge activity, where localised corona or breakdown discharge can damage insulation, leading to progressive degradation and eventual insulation breakdown. This type of issue would not be detected using standard diagnostic tests and it is possible for a motor to appear healthy whilst having high levels of Partial Discharge. Compared with other dielectric tests, the differentiating character of Partial Discharge measurements allows localised weak and aged points of the insulation to be identified.
Combining data with experience enables us to work in partnership with our customers to effectively manage and extend the life of their electro mechanical rotating machinery.
Get in touch with our team today to discuss how Houghton International can support your ongoing electric motor maintenance activities and reduce the risk of unplanned machine failures.
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