Replacing a Discontinued Corona Power Supply: Matching, Retrofit or Upgrade?

The corona generator on a ten-year-old line dies — and the model is discontinued. The mechanical line is fine; only the "engine" is gone. What follows is usually an expensive education in why a power supply cannot be bought by kW rating alone.

Why "same power" is not the same supply

A corona generator and its treating station form a coupled system. The electrode-to-roll gap behaves as a capacitor whose value depends on electrode geometry, gap, and dielectric. The generator's output circuit is designed against that capacitance. Install a supply whose output characteristics don't match the station, and you get exactly the symptoms buyers report after a hasty swap:

• output that never reaches rated power,
• instability that "tuning" doesn't fix,
• nuisance protection trips, stressed components, early failures.

Identical connectors and identical kW do not mean identical electrical behavior. This is the trap in replacement purchasing.

Your three options, in order of preference

1. Same-series successor

If the original manufacturer still exists, ask for the successor model and confirm it's specified for your station — electrode type, length, gap, supply frequency. Best outcome, least engineering.

2. Compatible replacement from a third party

A supply engineered to your station's parameters — not a catalog unit shipped as-is. The supplier must ask you for: electrode form (ceramic/metal), effective length, gap range, and station type; and they should offer a verification run before shipment. If a vendor quotes from a kW figure alone without asking about your station, keep looking.

3. Upgrade as a retrofit

If the station is also aging, replacing supply and station as a matched set — with modern protection (rotation interlock, fault indication), better efficiency, and documentation — often costs only modestly more and ends the "orphan parts" problem for another decade.

Verification before payment

Whatever the route, agree the acceptance test in writing: run the new supply with your station (or an identical reference station), check rated output, stability across the power range, and arc behavior on your film. Payment tied to that test — not to the shipment arriving.

What to send the supplier

A photo of the old nameplate (model, rated power, output specs), a photo of the station's electrode assembly, and — if known — the original station parameters. With those three items, a competent supplier can tell you within days whether you need a successor model, a matched build, or a full retrofit.