OMEF CPT180 excavator compactor

The OMEF CPT180 is the compactor that turns a 2 to 5 tonne mini excavator into a trench reinstatement machine. At 170 kg and 12 to 20 L/min it fits almost any compact carrier’s hammer circuit, and it lets the machine that dug the trench compact the backfill without a second piece of plant or a labourer on a walk-behind plate.

Where the CPT180 sits in the range

The CPT series has three sizes. The CPT180 is the mini excavator model; the CPT425 at 430 kg covers 5 to 9 tonne carriers and the CPT910 at 900 kg covers 12 to 20 tonnes. They sit alongside the TRV auger drive in the ground-preparation range, and the tillage and ground preparation guide explains where excavator-mounted compaction fits against rollers and against true forestry site preparation.

What the published figures mean on site

The headline figure is a stated force to ground of 18 t. That number is a supplier comparison figure produced under the manufacturer’s test method, and it is useful for ranking the three CPT models against each other. It is not a guarantee of field density. What a trench backfill actually achieves depends on the soil type, its moisture content, the thickness of each lift, the number of passes and the plate’s contact with the material, and a project with a specified density still needs its own field testing regardless of the plate’s rating. Read the 18 t as “the smallest of the three” and size the compaction program from the geotechnical specification, not from the brochure.

The other figures are the ones that make the CPT180 easy to put to work. Twelve to 20 L/min is a low flow requirement that most 2 to 5 tonne carriers deliver on the hammer circuit without adjustment, and 100 to 120 bar is a modest pressure that leaves headroom on any modern mini excavator. The 170 kg mass is roughly what a mini excavator would carry in a full bucket, so it is rarely a lift chart problem, although at full reach into a deep trench it is worth checking.

Carrier matching

The published band is 2 to 5 tonnes. Confirm the hammer circuit delivers within 12 to 20 L/min and that the carrier’s auxiliary relief is set within the 100 to 120 bar range; too much pressure or flow on a vibratory motor shortens its life rather than improving compaction. Ask Machinery Specialist whether the current build runs on a single-acting line with a free return or needs a double-acting circuit, whether a case drain is fitted, and what the return back-pressure limit is, then follow the hydraulic matching guide. Vibration through the boom is the other matching question: a plate compactor transmits shock into the dipper pins and the hitch, so isolation buffers and a hitch rated for the duty matter. The 1 to 5 tonne page covers compact carriers.

Typical work and production considerations

Service trench backfill on subdivisions, pathway and kerb bedding, landscaping fill, small foundation preparation and reinstatement around structures where a roller cannot go are the CPT180’s work. Production is measured in compacted cubic metres per hour or, on trenches, in linear metres of trench at a given width and lift. An illustrative model: a 450 mm wide trench backfilled in 200 mm lifts with the plate covering a 300 mm length of trench per placement, three passes per lift, gives a rate driven almost entirely by how quickly the operator can cycle the boom along the trench. The compaction itself is fast; the repositioning is the time. Compared with a walk-behind plate, the saving is the labourer, the manual handling and the ability to compact at the bottom of a trench nobody should be standing in. See subdivision and civil clearing and council parks and urban vegetation.

Limitations and when to choose a different family

A plate on a mini excavator compacts small areas that need reach; it does not compete with a roller on an open pad. Where the job is road base over a wide area, a roller wins on coverage and uniformity. Where the fill is deep and the specification demands a high density, the plate’s stated force is the first thing to check against the geotechnical requirement and the CPT425 may be the right tool on a larger carrier. The CPT180 is also not a root or stump tool; disturbed ground after clearing may need a stump cutter or stump grinder before any backfill is placed.

Options and configuration to settle at quotation

Settle the bracket and hitch (including whether a quick hitch is used and its weight), the hydraulic circuit type and any drain, hose lengths for the dipper, the carrier’s flow and pressure settings, plate width options and whether a rotation or tilt is offered. Ask for the delivered weight in the ordered configuration and the current hydraulic requirement in writing.

Wear parts and support

The base plate, isolation buffers, motor seals and bracket pins are the wear items, and the frame should be inspected for cracking at the vibration mounts. Price a buffer set and a motor seal kit with Machinery Specialist, confirm Australian stock, and read the wear parts guide.

Confirm before ordering

• The work is confined trench and small-area compaction where reach matters; open pads are roller work
• Project density specification reviewed and field testing budgeted; the 18 t figure is a comparison figure, not a density guarantee
• Carrier hammer circuit delivers 12 to 20 L/min and relieves within 100 to 120 bar
• Circuit type, case drain and return back-pressure limit confirmed in writing for the current build
• Hitch rated for vibratory duty and its weight included with the 170 kg head
• Lift chart checked at full reach into the deepest trench on the project
• Buffer set and motor seal kit priced and stocked in Australia
• Lift thickness and pass count set from the geotechnical specification, not the brochure

Frequently asked questions