ZF74 Steering Pump

For High Pressure Ram Systems

Ladoga

Military Users

Commercial Users

ANALYZING MANUFACTURES DATA

The New WARN HS9500i Manufacturers Published Figures

Well, 425amps is not just a large amount of current draw, it is more than 5 kilowatts, which is enough to heat a small house......from a 12 volt car battery?

The Popular SUPERWINCH X9 Manufacturers Published Figures

Okay it is marginally higher at 5.22kWatts, so the house would be a little warmer. So just how long are these winches going to work for and then what happens? Some manufacturers state "maximum 1 minute", others are a little coy and say "for intermittent use only" whatever that means.

The question I have a problem with is:- How can a little 12 volt battery, that has a problem turning an engine over for more than a few minutes, power a 4 tonne winch and pull the whole vehicle, up a steep hill or out of the gloop. I can see that it can because it says so above, but how come the isn't column to say for how long?

Alfred Murray Ltd H12/2speed Manufacturers Published Figures (ZF74/100PUMP)

No problems at all for the H12, 2 amps of battery power and the remainder easily provided by the hydraulic pump.

POWER CONSUMPTION EQUATION

TYPICAL CURRENT MODEL ELECTRIC WINCH

H12 HYDRAULIC WINCH

THE HEAT GENERATION EQUATION

TYPICAL CURRENT MODEL ELECTRIC WINCH

This heat is insulated by the electric motor's air gap and requires a long cool down period to dissipate. The winch is therefore only suitable for intermittent use, which under heavy load can mean just two or three minutes.

H12 HYDRAULIC WINCH

This heat is easily dissipated through the hydraulic motor casing and further radiated throughout the circulating hydraulic fluid.

When a ZF74 high flow pump is used to it's full capacity, the heat generated may increase to 500 watts so an small oil cooler may be a consideration, which will provide accelerated cooling of the system, allowing the winch to be used for indefinite periods without any nett heat gain.