Drilling Rig Electrical · DC control
Ross Hill 0522-2400-27 — DC Control Module, Series Type
The series-type DC control module in the Ross Hill / NOV 0522-2400 family — and why series and shunt boards are not interchangeable.
The series-type DC control module in the Ross Hill / NOV 0522-2400 family — and why series and shunt boards are not interchangeable.
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 | 0522-2400-27 |
|---|---|
| Manufacturer | Ross Hill / NOV |
| EI reference | EI-0522-2400-27 |
| System | Ross Hill / Hill Hayes / NOV SCR drilling |
| Module type | DC control — series type |
| Distinguishing feature | 1K ohm resistor |
| Condition | New-surplus, used-tested, reconditioned |
0522-2400-27 · 0522240027 · 0522-2400 · 2400-27 · Ross Hill DC control module series · RHCC DC module · EI-0522-2400-27
The DC control modules in a Ross Hill SCR house close the regulation loop for the DC drilling motors — taking the driller's setpoint and controlling SCR firing to hold speed and current. The 0522-2400 family covers several variants, and the dash suffix is what tells you which configuration a given board was built for.
This one is recorded as the series type, carrying a 1K ohm resistor. Series and shunt field configurations are genuinely different electrical arrangements with different load behaviour, so the distinction is not cosmetic.
This is the single most useful thing to take from this page. Within the 0522-2400 family you will find at least a series type and a shunt type, plus a regulation variant and the standard module NOV renumbered. They share a family number and a form factor. They are not documented as interchangeable, and a board that drops into the rack is not evidence that it is the right board.
| Number | What our records describe | Relationship |
|---|---|---|
| 0522-2400-27 | DC control module, series type, with 1K ohm resistor. | this page |
| 0522-2400-00 | DC control module, shunt type. | Different field configuration |
| 0522-2400-23 | DC control module, regulation. Sets SCR phase angle from the driller's handwheel setpoint. | Different variant |
| 0522-2400-21 | DC control module, standard. NOV 6415-2400-21. | Different variant |
Starting points for diagnosis, not a substitute for it.
| What you are seeing | What it usually indicates |
|---|---|
| Motor will not hold speed under load | Regulation loop — check the module and its feedback |
| A replacement board went in and behaves differently | Wrong variant for the field configuration — check the dash number |
| Fault clears on reseat and returns | Card-edge connector or backplane, not necessarily the card |
| One drive misbehaves and the others are fine | Compare dash suffixes across the boards in the house |
We verify the exact dash number against the physical unit before quoting and send photos of the label on the unit being offered. Send a photo of your board, or type out exactly what the label reads, and we will match the variant rather than guess at it.
These are the details that let us identify the right unit instead of guessing 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.