A new tower crane hoist from Potain, the largest frequency-controlled winch the company has ever produced, will premiere at bauma 2013 The 270 LVF 100 will be mounted on the counterjib of a large MD crane that will be sited at ground level on the Manitowoc booth. This will give visitors a detailed look at 200 kW-rated winch, which can handle loads of up to 40 t in four falls of reeving.
One notable new function on the 270 LVF 100 is its Power Control feature that allows it to operate off several different input power levels. This highly practical feature means that even on job sites where power supply is limited or at below-mains levels the winch can still function. Similarly, the winch also detects the rated power supply of the national network it is connected to and adjusts automatically, without operator intervention. This means that when the crane is transported to a different country with a different electrical grid, the crane will automatically adjust its settings.
For greater reliability and durability, the hoist’s converter and contactors are contained within a robust housing unit. The housing is pressurized to limit the intrusion of dust and has a thermostat-controlled heating and cooling system to protect crucial parts. When the motor temperature hits 80°C, the cooling system is activated for 3 minutes to reduce the motor temperature. If the motor remains at 80°C, additional 3-minute bursts of cooling continue until the motor temperature drops.
In addition, there are temperature limits built into system to protect it, yet maintain functionality. When the motor temperature exceeds 130°C, power is limited to 80 percent of the maximum to allow the winch to cool while still making it available for work. When the motor temperature exceeds 150°C, it shuts down. It remains off until the temperature falls to 140°C, when it can function at 80 percent capacity. Normal functioning returns when the temperature drops to 120°C.
For technicians, a 2 t capacity derrick and auxiliary winch is fitted to the housing allowing the fast and efficient change out of components. Maintenance on the crane is made easier as the motor’s windings are protected, extending the time between replacement.
Remi Deporte, Manitowoc’s global product director for Potain mechanisms, said owners, operators and technicians would all appreciate the capabilities and design of the 270 LVF 100.
“This new winch not only takes us to new levels of productivity with its speed and strength, but its design incorporates more functionality and reliability, combined with ease of maintenance for engineers,” he said. “We have a strong heritage in producing strong and capable winches dating back to our LCC series. As projects get larger and the demands on tower cranes grow, we wanted to propel the industry forwards in optimizing the functionality of a tower crane. This new 270 LVF 100 hoist embodies our approach.”
As with other frequency-controlled hoists from Potain, the 270 LVF 100 includes Optima technology which measures the load on the hook and allows the hoist to lift or lower at the maximum allowable speed. Additionally, Optima offers close control when positioning loads at slow speeds, while movements at higher speeds are reassuringly smooth, regardless of the size of the load on the hook.
The 270 LVF 100 works on 40 t Potain tower cranes, such as the MD 610 and MD 1100 special application crane. Maximum line speeds of up to 162 m/min can be achieved with the winch. In addition to the 270 LVF 100, Manitowoc has introduced the 270 LVF 80 winch, which is suited to the 32 t capacity version of the MD 1100.
Besides offering better performance than previous hoists of this capacity, the 270 LVF 100 is also more efficient, using less energy than its predecessors. As with all frequency-controlled hoists, when power comes from a generator energy consumption levels are much lower than those for traditional hoists. Plus, with the intelligent Power Control function, users of the new 270 LVF winches can also operate it with generators nearly half the size of those that would normally be required.