Heavy conductors and red switching components inside an electrical cabinet.

Specialties

SCR & DC Drive Systems

SCR modules, DC regulators and power stacks for legacy drive systems still running in the field.

Home›Specialties›SCR & DC Drive Systems

Edmundson Industrial in Houston, Texas is an independent supplier of legacy SCR and DC drive modules, regulator boards, SCR bridges and power stacks for GE, Ross Hill / NOV and Reliance systems. Send the full part number and a nameplate photo; condition, price and lead time are confirmed on the quote.

SCR and DC drives ran heavy industry for forty years, and plenty are still turning motors today. The control modules, regulator boards, and power stacks that keep them running are increasingly obsolete: we source them and cross-reference to available equivalents. Send the part number and we'll tell you what we can find.

Independent sourcing, not an authorized distributor. We supply new-surplus, used-tested, and reconditioned drive parts, with condition disclosed before sale.

What do we source?

Type	Notes
SCR drive modules	Firing boards, assignment, and control modules
DC regulators / controls	Speed and current regulator boards
Power modules & stacks	SCR / thyristor power stacks and bridges
DC drive systems	GE, Ross Hill / NOV, Reliance, and other legacy lines

How does an SCR / DC drive 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.

For the oilfield side of SCR drives, see Drilling Rig Electrical: Ross Hill / NOV control modules, SCR bay parts, and power modules.

Condition & sourcing

We supply SCR and DC drive 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.

For a documented Ross Hill drive-house contactor, see Ross Hill 0100-0389-02: DC contactor.

FAQ

What drive systems do you cover?

Legacy SCR and DC drives from GE, Ross Hill / NOV, Reliance, and others, plus the firing boards, regulators, and power stacks inside them. Send the board or module number and we will source or cross-reference it.

Do you handle the Ross Hill drilling drives here too?

Yes. The drilling side has its own pages, where we cover Ross Hill / NOV control modules, SCR bay components, and power modules in detail.

Can you supply obsolete SCR firing boards and power stacks?

Yes, as new-surplus, used-tested, and reconditioned. The thyristor stacks and firing boards are the parts that most often fail and the hardest to find; that is exactly our lane.

Are you an authorized distributor?

No. Edmundson Industrial is an independent surplus and sourcing company, not an authorized distributor. Condition is disclosed before sale.

Related equipment

Have a module or board number?

Send the full number, including the suffix, or a clear nameplate photo.

Request a Quote Email us (832) 975-8827