Ross Hill 0000-8500-00: AutoSync AC II Module

The AutoSync AC II module from Ross Hill / NOV SCR generator control: the card that brings an incoming generator into synchronism before it is paralleled onto the bus.

Independent supplier. RHCC 0000-8500-00 is identified from the installed number. Manufacturer and trademark names are used for reference only, and condition is disclosed before sale.

Part number	0000-8500-00
Manufacturer	Ross Hill / NOV
System	Ross Hill / Hill Hayes / NOV SCR drilling
Function	Generator synchronising
Condition	New-surplus, used-tested, reconditioned

Also searched as

0000-8500-00 · 0000850000 · 00008500-00 · 0000-8500 · 8500-00 · Rev C · Rev E · AutoSync · Auto-Sync · Auto Sync · AutoSync AC II · AC Module Auto Sync

What it does

On a diesel-electric rig, generators are paralleled onto a common bus as load demands. Before a set can be closed onto that bus, its voltage, frequency, and phase angle have to match what is already there. The AutoSync AC II module is the control that performs that match and permits the close.

When it degrades, the symptom is operational rather than electrical: a set that will not come online, takes a long time to sync, or closes roughly. Rough closure is the one to take seriously: paralleling out of phase is mechanically violent and expensive.

Symptoms that point here

Most people reach this page from a symptom rather than a part number. These are starting points for diagnosis, not a substitute for it.

What you are seeing	What it usually indicates
Generator will not synchronise or come onto the bus	Sync permissive not being issued
Sync takes far longer than it should	Matching loop degraded or drifting
Hard or rough closure when paralleling	Out-of-phase closure risk: stop and investigate before repeating
Set syncs on one unit but not another	Compare modules and dash suffixes across sets
Intermittent behaviour that worsens with vibration	Check card-edge connectors before condemning the card
Generator will not sync; autosync hunts without locking in	Module or calibration: the dash suffix is an engine calibration, and the wrong calibration will not sync even on a healthy module

Related and confusable numbers

Number	What it is	Substitute?
0000-8500-00	AutoSync AC II module, base number. Rev C and Rev E both confirmed in service.	baseline
0000-8500-18	Same module family, different engine calibration, recorded against CAT 3512B, 1200 RPM, 600 V 3-phase 60 Hz, 183 flywheel teeth, 199.4 µsec, mag pickup 3660 Hz @ 1200 RPM, PMG 240 VAC 120 Hz 1-phase, see the 0000-8500-18 page.	NOT a substitute
0001-2657	AC Module Auto Sync Aux II PCB: the auxiliary card inside the assembly, and frequently the item that actually failed.	Different item
0001-2656-00	3-phase AC control module, EMD engine applications.	Different engine family

The dash suffix on this module family is an engine calibration, not a revision level. A -18 will physically fit where a -00 came out and will not sync correctly, because it is matched to a different engine, flywheel tooth count, and pickup frequency. Confirm the full dash number, the revision, and the engine the unit was calibrated for before ordering.

Nameplate & revision

We verify the exact dash number and revision against the physical unit before quoting, and we send photos of the plate on the unit being offered. Send a photo of your nameplate, or type out what it reads, and we will match the revision rather than guess at it.

Condition and sourcing

RHCC 0000-8500-00 is quoted only after current availability, condition, and lead time are confirmed. Any offered unit is identified as new-surplus, used-tested, or reconditioned before sale.

If the observed failure does not line up with RHCC 0000-8500-00, use the SCR Drive Fault Finder to narrow the subsystem before requesting a part.

FAQ

What is the Ross Hill 0000-8500-00?

It is the AutoSync AC II module in Ross Hill / NOV SCR generator control. It matches an incoming generator's voltage, frequency, and phase to the running bus and permits paralleling.

What is the difference between 0000-8500-00 and 0000-8500-18?

The dash suffix is the engine calibration, not a revision. The -18 is recorded against a CAT 3512B at 1200 RPM with 183 flywheel teeth. Fitting the wrong calibration means the set will not sync properly. Match the suffix to your engine.

Which revisions exist?

Rev C and Rev E are both confirmed in service. We verify the revision on the physical unit before quoting and send plate photos of the actual item being offered.

My generator will not sync: is it definitely this module?

Not necessarily. The auxiliary PCB 0001-2657 inside the assembly is frequently the actual failure, and connector and vibration issues are common. Send us what the set is doing and the numbers off the cards before you buy anything.

Is it still available?

Not from original production. We source it as new-surplus, used-tested, and reconditioned, with condition disclosed before sale.

Availability & Quote

For RHCC 0000-8500-00, condition is disclosed before sale. Item photographs are supplied with an actual offer.

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

0000-8500-18 AutoSync Module Ross Hill / NOV Cross-Reference SCR House Replacement Parts SCR Houses Ross Hill AC Module Ross Hill DC Module Ross Hill / NOV

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