The generator exciter card in a Ross Hill / NOV SCR power house. It sits in the generator control section and drives the exciter field that sets generator output voltage.
Independent sourcing, not an authorized distributor. Ross Hill and NOV are trademarks of their respective owners, used here for reference only. We supply this item as new-surplus, used-tested, and reconditioned, with condition disclosed before sale.
| Part number | 0509-7901 |
|---|---|
| EI reference | EI-0509-7901 |
| Stock code | EL09-7901-00 |
| System | Ross Hill / Hill Hayes / NOV SCR drilling |
| Function | Generator control |
| Condition | New-surplus, used-tested, reconditioned |
| Also searched as | 0509-7901 · 05097901 · 7901 · EI-0509-7901 · EL09-7901-00 · Ross Hill · NOV · Hill Hayes |
In a Ross Hill SCR house each engine-generator set runs its output through a control section that regulates excitation. The exciter PCB is the card in that loop — it takes the voltage regulator's demand and drives the exciter field accordingly. When it degrades, the symptom shows up at the generator, not at the card: voltage that will not build, drifts under load, or hunts.
Most people arrive at this page from a symptom, not a part number. These are the failure signatures associated with this item. They are starting points for diagnosis, not a substitute for it.
| What you are seeing | What it usually indicates |
|---|---|
| Generator will not build voltage on start | Exciter field not being driven — check the exciter card before condemning the generator |
| Output voltage drifts or hunts under load | Regulation loop unstable; exciter card is one of the first items to check |
| One generator will not share load with the others | Excitation mismatch across sets |
| Voltage collapses when the SCR load steps on | Excitation cannot follow the load step |
Revisions differ across the production life of this equipment, and on some Ross Hill items the dash suffix carries a calibration rather than a revision level. We verify the exact dash number and revision against the physical unit before quoting, and we will send photos of the plate on the unit we are offering.
Send a photo of your nameplate, or type out what it reads, and we will match the revision rather than guess at it.
Supplied as new-surplus (unused, from the secondary market), used-tested, or reconditioned, with condition disclosed before sale and photos on request. Availability on legacy Ross Hill and NOV items changes constantly — send the number and we will tell you what we can actually find rather than quote something we cannot deliver.
Condition always disclosed before sale. Photos on request. Same-day response on most requests.
Condition disclosed before sale. Same-day response on most requests.