Soft starter repair and rebuild in Zambia
SCR stacks, firing cards, contactors and control boards repaired at component level — including the Lusaka Water contactor board we redesigned ourselves.
What we repair
Solid-state soft starters and reduced-voltage starters: SCR and thyristor power stacks, firing and gate boards, bypass contactors, current transformers, control supplies and fault displays. ABB, Schneider Altistart, WEG, Siemens, Motortronics and OEM starters inside pump and conveyor panels.
Typical faults
Shorted or open SCRs, failed firing pulses on one phase, motor that hums but will not start, nuisance trips on start, burnt bypass contacts, contactor coils that overheat and fail repeatedly, and starters damaged by voltage surges or load-shedding cycles.
The contactor coil problem
Coils that burn out again and again are usually a power-quality problem, not a coil problem. We built a contactor coil economizer for Lusaka Water precisely for this: pull-in at full current, then hold at reduced current, with surge protection. It has run since February 2026 with zero failures and the design study has been submitted to MDPI Electronics.
How the job runs
Intake logged with photos, diagnosis with oscilloscope and thermal camera, fixed quotation before work, load-tested on return, report per serial number.
Questions we are asked
Can a soft starter with blown SCRs be repaired?
Usually yes. We replace the thyristor devices, test the firing circuit on all three phases and run the starter at load before returning it.
Why do our contactor coils keep burning out?
Voltage surges and continuous holding current at elevated ambient temperature are the common causes. A coil economizer reduces holding current and protects against surges; we design and build them locally.
Do you supply replacement starters as well?
We repair first. Where a unit is beyond economic repair we advise on replacement and can commission the new one.
Related
Tell us what failed.
A photo of the unit and its nameplate on WhatsApp is enough to start.