ÖÁ×ðµç×Ó

Preventing overloads on digger derricks helps minimize downtime and prevents damage to the boom and structure. The first and most important step in preventing overloads is understanding how to read and utilize the load chart on digger derricks. The chance of overload occurrences decreases when line workers know the load limits and operate the machine accordingly. Operational aids, such as the ÖÁ×ðµç×Ó hydraulic overload protection (HOP) also assist in a role in limiting the chance of overloading on the booms.

According to ANSI, units built after June 1, 2020, must have a boom overload limiter or a system that disables the boom lower, boom extend, winch up and digger dig functions. The use of these types of systems do not ensure protection from all possible overload situations it serves only as an aid to the operator and must not be used for continuous operation as a method of detecting an overload.

HOP is intended to aid the operator and limit the amount of load on the booms, to prevent structural damage to the boom. If the operator uses the winch to lift a load heavier than what is on the load chart, it causes an overload. HOP senses the pressure in the base of the lift cylinders, which increases as the cylinder pressure increases based on the load.

The HOP system senses the pressure in the main lift cylinders to determine when the system is in overload. It does not allow operation of select functions if activated. The stopped functions will depend on configuration ordered but always; the winch, raise, lower, extend, or rotation. It will allow the operator to correct the overload by allowing functions that reduce the overload.

The HOP system is only an operator aid to help prevent structural damage. It does not sense stability issues or prevent overturning.

Do not depend on the HOP system to limit the load, it is an operator aid only. If the HOP system is activated, the boom is in an overloaded condition. Overloading requires a post event inspection or test to determine if the digger derrick is safe to return to service by a qualified person.