Drilling Rig SCR House Replacement Parts

Ross Hill and NOV SCR house parts: control modules, bridges, phase cells, console boards, contactors and fuses. Send a part number or describe the symptom.

An SCR house takes AC from the engine-generator sets and converts it to controlled DC for the drilling motors. When something in that chain fails, the rig stops. Most of this equipment is decades old, long out of production, and not stocked by mainstream distributors, which is exactly the gap Edmundson Industrial works in.

Independent sourcing, not an authorized distributor. Ross Hill, NOV, and other manufacturer names are used for reference only. We supply new-surplus, used-tested, and reconditioned equipment with condition disclosed before sale.

Start from the symptom

The Ross Hill SCR Drive Fault Finder maps the common failure signatures: gate firing pulse failure, misfire, one leg dead, phase loss, assignment dropout, autosync hunt: to the suspect module and its part number.

Most people calling about an SCR house do not have a part number yet: they have a rig that will not do something. These are the common entry points.

What the rig is doing	Where to look
Generator will not build voltage, or hunts under load	Generator exciter PCB
Engines bog or black out on simultaneous heavy loads	Power limit controller
Drilling motor will not reach speed, or overspeeds	Field supply PCB
Handwheel does nothing; console indication disagrees	Driller's console PCB
Semiconductor fuse blows repeatedly on one drive	SCR bridge phase cell
Reduced or absent dynamic braking	DWDB grid resistor
Drive will not take assignment	AC module DC module

These are starting points, not a diagnosis. Symptoms overlap across the control chain: tell us what you are seeing and we will help narrow it before you buy anything.

Control modules

The cards that regulate the drives. AC modules handle generator-side control and synchronising; DC modules set SCR phase angle and run the current and speed regulation loop for the drilling motors.

Item	Part number
Ross Hill AC Module	0521-2500 series	View ›
Ross Hill DC Module	0522-2400-23 · NOV 6415-2400-21	View ›
AutoSync AC II Module	0000-8500-00 · 0000-8500-18	View ›
DC Module, standard	0522-2400-21 · NOV 6415-2400-21	View ›
DC Module, series type	0522-2400-27	View ›
DC Module, shunt type	0522-2400-00	View ›
Power Modules	SCR power module assemblies	View ›

Power conversion

Where generated AC becomes controlled DC. Bridges, phase cells, pucks and the semiconductor fuses that protect them.

Item	Part number
Model 1400 SCR Bridge	0001-6307-70	View ›
Model 1500 Phase Cell	0100-0150-03	View ›
DC Contactor (Eaton / Cutler-Hammer)	6702ED584 · 0401-0021-00	View ›
DC Contactor (Ross Hill 1800/C)	0100-0389-02	View ›
Model 1400 Blower	0002-1076-62	View ›
SCR Bay Components	pucks, fuses, snubbers	View ›

Generator & field control

Excitation, power limiting and field supply: the loop that keeps the plant stable under drilling load.

Item	Part number
AutoSync AC II Module	0000-8500-00	View ›
Generator Exciter PCB	0509-7901	View ›
Power Limit Controller PCB	0509-7497	View ›
Field Supply PCB	0509-1300	View ›

Driller's console & protection

The operator interface and the protective functions behind it.

Item	Part number
Driller's Console PCB, PC1	0509-2500	View ›
Sprocket Slip PCB	0509-2600	View ›
DWDB Grid Resistor Assembly	0100-1000-04	View ›

Looking for a complete house?

This page covers replacement parts. If you are sourcing or evaluating a complete system, start at SCR Houses: including the used-house buying guide and SCR vs VFD, Model 1400, Model 1500, and rebuild & retrofit.

Cross-referencing Ross Hill to NOV

NOV retained most Ross Hill numbering after acquiring the line. The DC control modules are the main exception. Our Ross Hill / NOV cross-reference lists what we have confirmed, flags what we have not, and calls out the numbers that look interchangeable but are not.

FAQ

What parts of an SCR house do you supply?

Control modules (AC and DC), SCR bridges and phase cells, generator exciter and field supply boards, power limit controllers, driller's console boards, contactors, grid resistor banks, semiconductor fuses and SCR pucks. If it lives in a Ross Hill or NOV SCR house, send the number.

Do you handle both Ross Hill and NOV numbers?

Yes. NOV kept most Ross Hill numbering when it acquired the line. The DC control modules are the main place the numbers diverge: 0522-2400-21 cross-references to NOV 6415-2400-21. Our cross-reference page covers what we have confirmed.

Are these parts new?

We supply new-surplus, used-tested, and reconditioned equipment. Condition is disclosed before sale, with photos on request. We are an independent surplus and sourcing company, not an authorized distributor.

I do not know the part number: can you still help?

Yes. Tell us the rig, the model of SCR house, and what the equipment is doing. Most calls start from a symptom, not a number. Photos of the bay and the plate help enormously.

How fast can you respond?

Response timing is confirmed with the request. Actual lead time depends entirely on the item: legacy Ross Hill availability changes constantly, and we will tell you what we can genuinely find rather than quote something we cannot deliver.

Availability & Quote

Condition disclosed before sale. Photos on request. Response timing is confirmed with the request.

Request a quote by emailing sales@edmundsonindustrial.com or by calling (832) 975-8827

Rig down? Send the number or the symptom.

Condition disclosed before sale. Response timing is confirmed with the request.

Request a Quote