Drilling Rig Electrical
Electrical equipment for both sides of the rig: legacy Ross Hill and NOV SCR/DC systems, plus AC drives, VFD controls, motor control, switchgear, and distribution used on modern super-spec rigs.
Ross Hill Controls and the Hill Hayes SCR designs (now NOV) powered a generation of drilling rigs. Edmundson Industrial sources the control modules, SCR bay parts, and power that keep those systems running, and cross-references Ross Hill and NOV numbering both directions. We also source the AC drives, VFD control hardware, soft starters, motor control, switchgear, and distribution equipment used across modern AC rigs. AC or DC, send the full manufacturer number or equipment label and we will tell you what we can find.
How does a Ross Hill / NOV SCR system work?
| AC input | Bus from diesel engine–generator sets, commonly 600 V AC |
| Conversion | Phase-angle-controlled SCR (thyristor) AC-to-DC |
| DC output | 0–750 V DC, stepless |
| Per-SCR current | about 1600 A continuous, typical |
| Assignable to | Drawworks, mud pumps, and rotary table |
| Control | AC firing / assignment module plus DC regulation module (handwheel / throttle setpoint) |
Typical SCR drilling-system values; configurations vary by rig. Verify against the equipment.
DC drilling motor it drives
| Motor | GE752 high-torque DC drilling motor (industry standard) |
| Rated voltage | 750 V DC |
| Rated current | about 1185 A |
| Power | about 1130 HP (200–1200 kW range) |
| Construction | 12-pole, brush-type DC |
| Base speed | about 1040 RPM |
| Cooling | Separately-driven blower (about 2800 SCFM) |
Typical GE752 ratings shown for reference; verify against the motor nameplate.
Common Ross Hill / NOV part numbers
| Part number | Description |
|---|---|
| 0521-2500-14 | AC control module (firing / protection): also seen as 521250000 |
| 0522-2400-23 | DC control module (regulation) |
| 0522-2400-21 | DC module = NOV 6415-2400-21 |
| 6702ED584 | Eaton / Cutler-Hammer contactor used in the SCR bay |
Drilling electrical we source
| Part | Notes | Go |
|---|---|---|
| AC Drives & VFD Systems | Low- and medium-voltage drives, boards, I/O, cooling, braking, and motor-control hardware for modern AC rigs | AC drives › |
| AC Control Module | Firing and protection: 0521-2500-14 | AC module › |
| DC Control Module | Regulation: 0522-2400-23 / NOV 6415-2400-21 | DC module › |
| SCR Bay Components | Contactors, blowers, panel meters, instrumentation | SCR bay › |
| Power Modules | SCR power stacks and DC drive stacks | Power modules › |
| Cross-Reference | Ross Hill ↔ NOV numbering | Cross-reference › |
All Ross Hill / NOV part numbers we cover
Every Ross Hill / NOV part page on this site, by OEM part number. If your number is not listed, send it anyway: documented numbering discrepancies and collapsed no-dash formats are normal on this equipment.
- 0521-2500-14, AC control module, firing / protection
- 0521-2500-32: AC control module
- 0521-2500-00: AC control module (base family 0521-2500)
- 0521-2400-21: exact-match DC control module identification; verify the installed label
- 6702ED584-2: Eaton DC contactor, 1800 A 115 VDC coil
- 0522-2400-23, DC control module, regulation
- 0522-2400-00, DC control module, shunt type
- 0522-2400-21: DC control module (NOV 6415-2400-21)
- 0522-2400-27, DC control module, series type
- 0000-8500-00: AutoSync AC II module
- 0000-8500-18, AutoSync AC II, calibrated variant
- 0001-6307-70: Model 1400 SCR bridge
- 0002-1076-62: Model 1400 blower
- 0100-0150-03: Model 1500 phase cell
- 0100-0389-02: DC contactor, Ross Hill 1800/C
- 0100-1000-04: DWDB grid resistor assembly
- 0509-1300: Field supply PCB
- 0509-2500-00: Driller’s console PCB (base family 0509-2500, PC1)
- 0509-2600: Sprocket slip PCB
- 0509-7497: Power limit controller PCB
- 0509-7901-00: Generator exciter PCB (base family 0509-7901)
- 6702ED584: Eaton DC contactor, 1800 A 74 VDC
- 10509209-001: NOV dynamic brake resistor bank
- 0301-0009-00 – Fuse, 6/10 A (0.6 A), 500 V
- 0302-1500-00 – Motor circuit protector, GE TEC36030WL, 30 A
- 0410-0015-00 – Starter coil, GE 15D21G002, 120 V
- 0506-0001-00 – Rheostat, 1000 ohm, 25 W
- 0801-0060-02 – DC voltmeter, 0-1000
- 1303-2110-00 – Motor starter, GE CR306C002, NEMA size 1
- 1303-2113-00 – Motor starter, CR306E002, NEMA size 3
- 0410-0022-00 – Starter coil, 55-501336G002, 120 V identification
- 0409-0068-00 – Contact kit, 55-153677G002, NEMA size 3
- 1305-2006-00 – Overload relay, CR324E310FX, NEMA size 3
- 0100-0135-00 – Torque-limit dual rheostat, D1N200P102UA
- 0402-0039-00 – KUP-14A55-120 relay, 120 VAC coil, 3PDT
- 0402-0043-00 – KUP-14D55-24 relay, 24 VDC coil, 3PDT
- 0403-0080-00 – E19-50H throttle microswitch
- 0301-0010-00 – Mersen ATQ2, 2 A time-delay fuse
- 0301-0019-00 – Mersen ATM30, 30 A fast-acting fuse
- 0302-0505-00 – THED136015WL, obsolete 15 A breaker
- 0302-1509-00 – TEC36007WL, 7 A motor circuit protector
- 1303-2114-00 – Motor starter, CR306F002, NEMA size 4
- 0410-0018-00 – Starter coil, 55-501463G002, NEMA size 4
- 0409-0030-00 – Contact kit, 55-153678G002, NEMA size 4
- 1305-2007-00 – Overload relay, CR324F310FX, NEMA size 4
- 1303-2112-00 – Motor starter, CR306D002, NEMA size 2
- 0410-0016-00 – Starter coil, 15D22G002, NEMA size 2
- 1305-2005-00 – Overload relay, CR324D310FX, NEMA size 2
- 1304-2045-00 – Overload heater, CR123C303B, NEMA size 2
- 0301-0011-00 – Mersen ATQ3-1/2, 3.5 A time-delay fuse
- 0301-0012-00 – Mersen ATQ6, 6 A time-delay fuse
- 0301-0013-00 – Mersen ATQ10, 10 A time-delay fuse
- 0301-0048-00 – Mersen TRM6/10, 0.6 A time-delay fuse
- 0302-0504-00 – THED136100WL, 100 A high-break circuit breaker
- 0302-0513-00 – THED136150WL, 150 A high-break circuit breaker
- 0302-1508-00 – TEC36015WL, 15 A motor circuit protector
- 0302-1501-00 – TEC36050WL, 50 A motor circuit protector
- 1304-2010-00 – Overload heater, GE CR123C163B
- 1305-2001-00 – Overload relay, GE CR324C310F9X2
- 0100-0134-02 – Dual rheostat assembly, hand throttle
- 0302-0552-00 – Circuit breaker, GE THED136060WL, 60 A
- 1003-0066-00 – Control supply transformer, 150 VA
- 1004-0004-00 – Sync transformer, 600:120
- 0000-6818-98 – Westcode diode, forward, SCR bay
- 0000-6818-99 – Westcode diode, reverse, SCR bay
- 0001-1467-38 – Complete foot throttle assembly
- 0100-0333-02 – Model 1400 blower, 3/4 HP
- 0100-0357-00 – Firing transformer
- 0501-0616-10 – SCR thyristor, SCR bay
- 0506-0003-00 – Foot throttle rheostat, 200 ohm
- 0509-0700-00 – Ammeter PC card, generator group
- 0509-1200-00 – DC slide PCB
- 0509-3900-00 – Power limit PCB
- 0801-0007-02 – DC ammeter, 0-2000
- 1003-0008-00 – AC regulator transformer
Starting from a symptom instead: a gate firing pulse failure, a misfire, phase loss, a drive that will not take assignment? Use the Ross Hill SCR Drive Fault Finder to get from what you are seeing to the suspect module, then to the part number.
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.
FAQ
Are Ross Hill and NOV parts the same?
Can you supply obsolete or discontinued modules?
Do the AC and DC modules work as a pair?
Where are you located?
Industrial electrical sourcing guides
- Discontinued GE breaker cross-reference
- Eaton and Cutler-Hammer breaker cross-reference
- Westinghouse to Eaton breaker cross-reference
- Square D obsolete breaker cross-reference
- Obsolete circuit breaker sourcing
- Siemens G120 VFDs
- VFDs, motor control, and legacy SCR/DC drives
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
Rig down? Send us the Ross Hill or NOV part number.
Condition disclosed before sale. Response timing is confirmed with the request.