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Brand
Ross Hill
Ross Hill is the name behind a large share of the SCR drive systems on DC-electric land and offshore drilling rigs. Ross Hill Controls built SCR systems that convert AC from the rig’s generators into variable DC for the drawworks, mud pumps and rotary table. Its drilling business was part of Ansaldo Ross Hill until National-Oilwell, now NOV, bought it in April 1997. Seven Star LLC is an independent supplier in Muscat. We list Ross Hill SCR control modules and source Ross Hill spare parts for drilling contractors and rig operators in Oman and the GCC by part number.
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Brand profile
About Ross Hill
- Speciality
- SCR drilling rig drive systems
- Listed with us
- 1 product
Ross Hill products by category
Ross Hill is the name behind a large share of the SCR drive systems on DC-electric land and offshore drilling rigs. Ross Hill Controls built SCR systems that convert AC from the rig’s generators into variable DC for the drawworks, mud pumps and rotary table. Its drilling business was part of Ansaldo Ross Hill until National-Oilwell, now NOV, bought it in April 1997.
Seven Star LLC is an independent supplier in Muscat. We list Ross Hill SCR control modules and source Ross Hill spare parts for drilling contractors and rig operators in Oman and the GCC by part number.
Ross Hill at a glance
| Known for | SCR (silicon-controlled rectifier) drive systems for land and marine drilling rigs |
|---|---|
| Ownership history | Ross Hill Controls, part of Ansaldo Ross Hill; its drilling business was acquired by National-Oilwell (now NOV) in April 1997 |
| Installed base | Many DC-electric rigs still run Ross Hill SCR houses, so control cards and modules remain in demand |
| Applications | Drawworks, mud pumps, rotary tables and top drives driven by DC motors |
Ross Hill parts we list
| Part | Type | Use |
|---|---|---|
| DC control module, P/N 2260-000001 | SCR system control module | Control electronics in a Ross Hill SCR drive bay |
On an SCR rig, diesel generators feed a common AC bus. Each SCR bay rectifies that AC into a DC voltage the driller can vary, which sets the speed and torque of the DC traction motors on the drawworks, mud pumps and rotary table. The control modules fire the thyristors, limit current and handle the assignment of bays to motors, so a failed card can stop a pump or the drawworks.
Where Ross Hill SCR systems are used
In Oman and the GCC, Ross Hill SCR systems are found on older and refurbished land drilling rigs and workover rigs, where operators keep spare control modules on hand to avoid downtime.
Ordering Ross Hill parts: what we need
Send the Ross Hill part number from the card or module, a photo of the label, and the rig’s SCR system type if known. If the original part is obsolete, the part number and photo let us check for a compatible repaired or replacement unit.
Facts checked against NOV (National-Oilwell) records and rig equipment listings, October 2026.
Request a Quote for Ross Hill Products
Looking for Ross Hill parts not listed here, or pricing for a project? Send us the part numbers and quantities. Seven Star LLC sources genuine Ross Hill products for customers across Oman and the GCC and replies with a formal quotation.
- Genuine OEM products
- Supply across Oman & the GCC
- Formal quotation from our sales team
Free, no-obligation quotation · takes about 1 minute
Other enquiries: [email protected] · WhatsApp
Frequently Asked Questions
How do I identify the correct Ross Hill control module?
By the part number on the module label, such as 2260-000001 for the DC control module, together with any revision marking. Modules that look alike can differ internally between system generations. Send photos of the label, the front panel and the rear connector, and note the bay the module came from, so the match can be checked before ordering.
What is the difference between the Ross Hill AC module and DC module?
In an SCR drive system the AC control module belongs to the generator section, where it handles generator control. The DC control module belongs to the SCR bay and controls the DC output that feeds the drilling motor. The two are not interchangeable, so name the one you need by part number.
Can a module with a different revision be used as a replacement?
Only when the documentation for your system confirms it. Revisions can change connectors, adjustment ranges or the cards a module works with. We quote the part number and revision you send. If only a later revision can be sourced, we tell you which one it is so your electrical supervisor can check it against the system manual.
Who supports Ross Hill drilling controls today?
Ross Hill Controls was part of Ansaldo Ross Hill, and its drilling business was acquired by National-Oilwell, now NOV, in April 1997. Many DC-electric land and marine rigs still run Ross Hill SCR houses, so control cards and modules remain in demand.
Is Seven Star LLC a distributor of Ross Hill?
No. Seven Star LLC is an independent supplier that sources Ross Hill control modules and SCR parts through commercial channels. We check the part number against the documentation available for the system, tell you when a number has been superseded, and pass on the manufacturer's documents supplied with the part on request.