The 0521-2500-32 AC control module from a Ross Hill / NOV SCR house — one variant in the 0521-2500 AC control family.
Independent sourcing, not an authorized distributor. Ross Hill, NOV, and other manufacturer names and part numbers are used for reference only. Supplied as new-surplus, used-tested, or reconditioned, with condition disclosed before sale.
| Part number | 0521-2500-32 |
|---|---|
| Manufacturer | Ross Hill / NOV |
| EI reference | EI-0521-2500-32 |
| Stock code | EL21-2500-32 |
| System | Ross Hill / Hill Hayes / NOV SCR drilling |
| Function | AC control |
| Condition | New-surplus, used-tested, reconditioned |
0521-2500-32 · 0521250032 · 0521-2500 · 521-2500-32 · 2500-32 · EI-0521-2500-32 · EL21-2500-32 · AC Control Module · RHCC · Ross Hill AC module · NOV AC module
The AC control modules in a Ross Hill SCR house handle the generator-side control functions — the AC portion of the system, as distinct from the DC modules that regulate SCR firing for the drilling motors. The 0521-2500 family covers several variants, and the dash suffix identifies the specific configuration.
Because these modules were built in variants across frequency, engine, and feature configuration, the dash number matters as much as the base number. A module from the same family is not automatically a replacement.
Most people reach this page from a symptom rather than a part number. These are starting points for diagnosis, not a substitute for it.
| What you are seeing | What it usually indicates |
|---|---|
| AC control functions unavailable or erratic | Module or its supply — verify voltages at the card first |
| Set behaves differently from an otherwise identical set | Compare dash suffixes between the two |
| Fault clears on reseat and returns | Card-edge connector or backplane, not necessarily the card |
| Module physically fits but does not function correctly | Wrong variant for the configuration — check the dash number |
| Number | What it is | Substitute? |
|---|---|---|
| 0521-2500 | AC control module, RHCC — the base family number. | Same family |
| 0521-2500-14 | AC control module, 50 Hz variant. | Verify frequency |
| 0521-2500-19 | AC module with reverse power relay. | Different feature set |
| 0521-2500-35 | AC control module, 50/60 Hz. | Verify frequency |
| 0521-2400-21 | DC control module — related numbering, different function entirely. | NOT an AC module |
We have not confirmed what the -32 suffix designates within the 0521-2500 family, and we will not publish a specification we have not verified. What we do know is that the family spans 50 Hz, 60 Hz, 50/60 Hz, and reverse-power-relay variants. Send the full dash number off your module and the frequency and engine configuration of the set, and we will match the variant rather than guess at it.
We verify the exact dash number and revision against the physical unit before quoting, and we send photos of the plate on the unit being offered. 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 equipment changes constantly — send the number and we will tell you what we can actually find.
Condition always disclosed before sale. Photos on request. Same-day response on most requests.
Condition disclosed before sale. Same-day response on most requests.