New and proven

Enerpac's new 700 bar operating pressure ZU4 hydraulic pump was developed to serve the construction industry in tasks that include powering medium to large cylinders and hydraulic tools, post-tensioning and foundation repair. Designers of the two-stage portable electric hydraulic pump were aiming for increased ease of use, improved operating characteristics, longer life and easier maintenance.

Models are offered for either 115 V or 230 V operation. Portability is important for this type of site equipment, so the new pump is designed to be compact and to weigh as little as possible. It has a thermally insulated handle and an optional tubular steel skid frame to give the pump an extra-wide stance and make it easier to carry.

For a good power-to-weight ratio the design uses a universal motor with hydraulic circuit and drive-end improvements to maximise hydraulic output and minimise current draw. The ZU4 draws 18 % less current than comparable pumps, Enerpac claims. Other benefits are a low start current draw, which reduces the likelihood of tripping breakers, and tolerance of a low supply voltage without overheating.

For operation in high ambient temperatures an optional heat exchanger stabilises the oil temperature at 54 ⁰ C or less. The control pendant is designed to combine weather resistance and safety by incorporating sealed switches and operating on 15 V DC.

Many features of the new pump design have been incorporated to increase reliability and extend the life of the pump, including: fewer moving parts; a lower internal temperature; heavy-duty, oversize bearings; and oil bath lubrication.