Ross Hill / NOV Cross-Reference
How Ross Hill and NOV part numbers line up, including where NOV used distinct numbers. Reference only; verify against the nameplate.
When NOV acquired Ross Hill Controls and the Hill Hayes SCR line, most numbering carried straight over, so in most cases the Ross Hill number and the NOV number are the same. The DC control modules are the main place that changed. Here's how the common numbers line up.
What a cross-reference can and cannot tell you
Read this before you use the table. A cross-reference is an identification aid. It is not a statement that two parts are interchangeable, and on this equipment the difference matters.
- Same number is not the same thing as same part. NOV carried most Ross Hill numbering forward unchanged, so an identical number across both brands is normal and expected. It still needs verifying against the label.
- The dash suffix usually carries the real information. Across these families a suffix can mean a frequency, an engine calibration, a motor field configuration, or a coil voltage. Two modules that share a base number and differ in the suffix are commonly not substitutes for one another.
- Mechanical fit proves nothing. Most of these boards will drop into the rack whether or not they are correct for the set. The failure shows up afterwards, in behaviour rather than in fitment.
- Some cross-reference entries require nameplate confirmation. Those entries are identification leads, not interchange statements.
- The physical nameplate outranks every secondary reference. If paperwork and hardware disagree, send the complete installed label.
Starting from a symptom rather than a number: no firing pulses, a misfire, one leg dead? The SCR Drive Fault Finder maps what you are seeing to the suspect module first.
Ross Hill to NOV cross-reference
Where the numbering lines up, where it does not, and where we have a detail page with the identification cautions for that specific item.
| Ross Hill P/N | NOV / equivalent | Part | Notes |
|---|---|---|---|
| 0000-8500-00 | (same) | AutoSync AC II module | Generator synchronising. Rev C and Rev E both in service. |
| 0000-8500-18 | (same) | AutoSync AC II, calibrated variant | Dash suffix is an engine calibration, not a revision. Not a substitute for the -00. |
| 0521-2500 | (same) | AC control module (RHCC) | Base family number. SCR gate firing, drive assignment and protection. |
| 0521-2500-14 | (same) | AC control module | Recorded as 50 Hz. Also seen as 521250000. Verify frequency against your set. |
| 0521-2500-32 | (same) | AC control module | Variant within the AC family; suffix not yet characterised. |
| 0522-2400-23 | (same) | DC control module, regulation | Sets SCR phase angle from the driller's handwheel setpoint. |
| 0522-2400-21 | 6415-2400-21 | DC control module, standard | The one confirmed case where NOV assigned its own number. |
| 0522-2400-27 | (same) | DC control module, series type | Series field type, with 1K ohm resistor. Not a substitute for the shunt type. |
| 0522-2400-00 | (same) | DC control module, shunt type | Also recorded as 0522-2500-00: a known numbering discrepancy on this item. |
| 0521-2400-21 | (same) | DC control module | Exact-match identifier; no interchange with 0522-2400-21 is assigned. Confirm the physical board label. |
| 0401-0021-00 | 6702ED584 | DC contactor, 1800 A 74 VDC | An Eaton / Cutler-Hammer part, not a Ross Hill-built one. Coil voltage varies by suffix. |
| 0100-0389-02 | (same) | DC contactor, Ross Hill 1800/C | Same 1800 A / 74 VDC headline rating as the Eaton 6702ED584 and a different part. Do not treat them as interchangeable. |
| 0002-1076-62 | (same) | Model 1400 blower | 2 HP 600 V 3-phase. SCR bay and module cooling. |
| 0001-6307-70 | (same) | Model 1400 SCR bridge | Thyristor bridge assembly. |
| 0100-0150-03 | (same) | Model 1500 phase cell | Explicitly not interchangeable with Model 1400 cells. |
| 0100-1000-04 | (same) | DWDB grid resistor assembly | Drawworks dynamic brake grid. A different item from the resistor bank below. |
| No RHCC number listed | 10509209-001 | Dynamic brake resistor bank | An NOV number. A different item from grid resistor 0100-1000-04. |
| 0509-2500 | (same) | Driller's console PCB (PC1) | |
| 0509-1300 | (same) | Field supply PCB | |
| 0509-2600 | (same) | Sprocket slip PCB | Single-phase. Protection function on hoisting equipment. |
| 0509-7497 | (same) | Power limit controller PCB | |
| 0509-7901 | (same) | Generator exciter PCB |
Reference only. Verify every number against the nameplate before ordering. Rows marked in red require physical-label confirmation and do not state interchangeability.
Numbers that are easy to confuse
| These look related | But | What to do |
|---|---|---|
| 0000-8500-00 and 0000-8500-18 | the suffix is an engine calibration, not a revision | Match the suffix to the engine, flywheel tooth count and pickup frequency |
| 0522-2400-27 and 0522-2400-00 | one is the series field type, the other the shunt type | Establish how the motor field is wound before ordering either |
| 0521-2400-21 and 0522-2400-21 | no interchange is assigned; the 0521 form requires nameplate confirmation | Use the complete identifier printed on the physical board |
| 6702ED584 and 6702ED584-2 | the suffix changes the coil voltage (74 VDC vs 115 VDC) | Read the full number and confirm the coil voltage your bay supplies |
| 6702ED584 and 0100-0389-02 | same 1800 A / 74 VDC rating, different manufacturers | Check the manufacturer name on the nameplate, not just the rating |
| 0100-1000-04 and 10509209-001 | both are braking resistors and they are different assemblies | Confirm which one your drawworks brake actually uses |
| Model 1400 and Model 1500 parts | phase cells are explicitly not interchangeable between platforms | Establish the SCR platform first, then order against it |
Condition & sourcing
We supply Ross Hill and NOV drilling parts as new, new-surplus, used-tested, and reconditioned, with condition disclosed before sale and photos on request. We are an independent surplus and sourcing company, not an authorized distributor.
What replaces an obsolete Ross Hill SCR drive module?
Most legacy Ross Hill / NOV modules have a direct like-for-like replacement (new-surplus, used-tested, or reconditioned), and every one of them also has a modern retrofit path when a like-for-like swap is no longer viable. Use the table to map the number printed on your board to its direct replacement and its retrofit alternative. Verify Model 1400 vs Model 1500 generation before ordering: phase cells and several PCBs are not interchangeable across generations.
| Legacy OEM Part | Function | Direct Replacement Module | Modern Retrofit Path | Fit Notes | Availability |
|---|---|---|---|---|---|
0521-2500 AC control module (RHCC) | SCR gate firing, drive assignment (mud pump / drawworks / rotary table), and system protection | 0521-2500-32: verify dash suffix and 50/60 Hz against your set | PLC-based AC control retrofit within the existing SCR house footprint | Also seen collapsed as 521250000. Symptom pointer: missing or erratic gate firing pulses, drive assignment dropout. | RFQ: timing confirmed with the request |
0522-2400-00 DC control module, shunt type | DC motor field regulation, shunt-wound drilling motors | Same number, sourced: also recorded as 0522-2500-00 | Solid-state DC field controller retrofit | Not interchangeable with 0522-2400-27 (series type). Confirm field configuration from the motor, not the drawing. | RFQ: timing confirmed with the request |
0001-6307-70 Model 1400 SCR bridge | Main AC-to-DC power conversion, one bay | Same number, sourced | Bay rebuild with current-production SCR devices and matched firing boards | Symptom pointer: repeated semiconductor fuse loss, one leg dead, unstable DC output under load. Model 1400 bridge: do not fit to a 1500 bay. | RFQ: timing confirmed with the request |
0100-0150-03 Model 1500 phase cell | SCR power conversion, Model 1500 generation | Same number, sourced | Bay rebuild with current-production SCR devices and matched firing boards | Explicitly not interchangeable with Model 1400 cells. Verify the generation before ordering. | RFQ: timing confirmed with the request |
0000-8500-00 AutoSync AC II module | Generator synchronising | Same number, sourced: Rev C and Rev E both in service | Addressed as part of a control section refresh | The -18 suffix is an engine calibration, not a revision: the wrong calibration will not sync even on a healthy module. | RFQ: timing confirmed with the request |
6702ED584 DC contactor, 1800 A 74 VDC | DC power contactor in the SCR bay | Same number, sourced: Ross Hill reference 0401-0021-00 | Contactors inspected during rebuild; contacts and coils addressed | Coil voltage varies by suffix. Same headline rating as Ross Hill 0100-0389-02 and a different part: not interchangeable. | RFQ: timing confirmed with the request |
0002-1076-62 Model 1400 blower | SCR bay and module cooling (2 HP, 600 V 3-phase) | Same number, sourced | Cooling restored during rebuild: blowers, filters, airflow paths | Overheating bays and thermal trips are a cooling symptom before they are an electronics symptom. | RFQ: timing confirmed with the request |
Number not in the table? Send whatever is printed on the board, including numbers that look wrong, to Request a Quote. Documented numbering discrepancies (2400 vs 2500 middle groups, collapsed no-dash formats) are normal on this equipment and we cross-reference them daily.
FAQ
Did NOV change the Ross Hill part numbers?
Is your cross-reference guaranteed?
Which Ross Hill or NOV identifier can I send?
Are you an authorized distributor?
Request a Quote
or send the part number to sales@edmundsonindustrial.com · (832) 975-8827 · Houston, TX. Response timing is confirmed with the request.
Related
Send the Ross Hill or NOV number and we'll identify and source it.
Condition disclosed before sale. Response timing is confirmed with the request.