Drilling Rig Electrical · SCR bay contactors
Ross Hill 0100-0389-02 — DC Contactor (1800/C)
The Ross Hill 1800 A / 74 VDC DC contactor — and why it is not the same part as the Eaton contactor of identical rating.
The Ross Hill 1800 A / 74 VDC DC contactor — and why it is not the same part as the Eaton contactor of identical rating.
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 | 0100-0389-02 |
|---|---|
| Manufacturer | Ross Hill / NOV |
| Designation | Ross Hill 1800/C |
| EI reference | EI-0100-0389-02 |
| Type | DC contactor |
| Rating on file | 1800 A, 74 VDC |
| System | Ross Hill / Hill Hayes / NOV SCR drilling |
| Condition | New-surplus, used-tested, reconditioned |
0100-0389-02 · 0100038902 · 0100-0389 · 1800/C · 1800C · Ross Hill 1800 amp contactor · Ross Hill DC contactor · EI-0100-0389-02
There are two different 1800 A / 74 VDC DC contactors associated with Ross Hill SCR equipment:
Identical headline ratings, different manufacturers, different part numbers. We have no evidence that they are interchangeable and we will not imply that they are. If a parts list says one thing and the hardware in the bay says another, trust the nameplate and send us a photo.
DC contactors in an SCR bay make and break the DC power feed to the drilling motors and handle drive assignment — connecting a given SCR bay to the drawworks, a mud pump, or the rotary table. They switch high DC current, which is electrically harder than switching AC because there is no natural current zero to help extinguish the arc. That is why these are heavy, purpose-built devices with blowout arrangements rather than general-purpose contactors.
It is also why they wear. Contact erosion is the normal failure mode, and it is load-dependent rather than time-dependent.
| What you are seeing | What it usually indicates |
|---|---|
| Contactor will not pull in | Coil or control circuit — verify coil voltage first |
| Chatter or drop-out under load | Coil supply or worn contacts |
| Visible pitting, welding, or material transfer on the tips | Contacts at end of life |
| Drive assignment does not follow the console selection | Contactor or its control, not necessarily the drive |
| Arcing or scorching in the bay | Stop and investigate before re-energising |
We verify the number and rating against the physical unit before quoting and send photos of the nameplate on the unit being offered. Because two different 1800 A contactors exist in this equipment, a plate photo is worth more here than a part number from a spreadsheet.
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.