Power Packs for Core Drills and Disc Cutters

How a hydraulic power pack for core drills and saws works

A power pack holds an engine or motor, a pump, an oil reservoir, a filter and a cooler. The pump pushes oil down a pressure hose into the tool's hydraulic motor; the fluid returns through a second hose. The circuit is closed and carries no electricity, which is why a wall saw, a wire saw or a core drill can work in running water, in a trench, or even submerged.

The second advantage is power density. A 230 V socket on a 16 A breaker delivers around 3.5 kW — enough for holes up to roughly 200 mm. A hydraulic set-up carries 9–20 kW to a head weighing 10–20 kg, because engine and cooling stay in the module.

Electric, petrol or high-frequency power pack

Choosing the drive is a decision about where you work, not about output. An electric hydraulic pack needs a 400 V supply on a 16–32 A breaker, gives off no fumes and may stand inside a building. A petrol version in the 9–25 hp bracket needs no installation, but has to stand in a well-ventilated spot. A third group is high-frequency (HF) power packs: they move no oil, but send high-frequency current down a cable to the HF motors of wall saws and wire saws.

Selecting a power pack: flow, pressure, couplings

The power pack follows the machine, never the other way round. Starve the tool of oil and it bogs down; feed it far more than it was built for and temperature climbs while seal life drops. Four things to check before you buy:

• Flow rate: lighter core drills and hand-held cutters run at 20–35 l/min, wall saws and wire saws at 35–65 l/min.
• Working pressure: typically 140–230 bar; set the relief valve to the value in the tool manual.
• Couplings and hoses: flat-face quick couplings are the standard; runs longer than about 10–20 m cost pressure at the tool.
• Cooling: packs built for sawing carry an oil cooler; oil above roughly 70 °C is a signal to pause.

Complete the set with diamond core drill bits chosen for the aggregate and reinforcement, and with complete core drills supplied with a stand.

Frequently asked questions about power packs