Marco UP3/OIL Oil Transfer Pump connections

UP3/OIL 16402012 is the 12 V oil-transfer model, not the water or reversible-control variant. The manual allows oils within its viscosity and temperature limits, including a maximum viscosity of 350 cSt and oil temperature of 85°C. It prohibits water and gasoline. Check the particular fluid’s compatibility and fire characteristics before use; similar hose connections do not make this a bilge, drinking-water or petrol pump.

The manual’s 12 V oil performance graph shows approximately 4.5 A at 25°C and 3.5 A at 45°C. This entry uses 4.5 A only as that graph’s nominal planning point; colder or more viscous oil and different backpressure can increase demand. No startup maximum is published. Use the specified 7.5 A fuse, positive red and negative black. For the manual’s up-to-2-metre short-wire case use at least 1.5 mm²; the example limits each leg to 0.75 m, and longer routes require a separate calculation.

Install secure compatible hoses, respect the flow arrow and prevent air leaks at the suction fittings. Use the recommended inlet filtration and an adequately vented source/receiving tank. Keep the outlet from becoming unintentionally blocked; do not assume an electrical fuse regulates delivery pressure. Mount the motor in a protected ventilated location. The manual prohibits PWM control because of its electrical filtering arrangement; use a suitable conventional switch instead.

Prime and test with the actual oil temperature and route, checking flow, leakage, loaded voltage and current. Continuous operation is conditional: the manual limits it to pressure no greater than half the pump’s declared maximum while motor temperature remains within its stated 60–70°C range. A short transfer of warm oil does not prove continuous cold-oil capability. Stop if the motor becomes excessively hot, flow collapses or current rises unexpectedly, and isolate power before clearing a restriction.

Marco installation manual, Rev 09, December 1 2022; English pp. 7–11 installation, prohibited fluids and fuse/wire table; p. 14 visually checked performance graphs; manufacturer-authored mirror. The original PDF is retained in the marine source ledger. This page uses an overview because the published operating estimate does not establish peak current for a complete cable-sizing example. The drawing represents the identified electrical interfaces; it does not simulate the equipment’s mechanical performance, radio signals or fluid system. Unpublished connector ampacity and startup current remain unspecified.