Every elevating device has a loading classification pertaining to the capacity of the elevating device and to the nature of the loading method. It is important that the loading classification matches the intended use of the elevating device in order to ensure safe operation.
Class A Loading
Most passenger elevator systems and standard freight elevators are designed as Class A, or “General Freight Loading”. The actual amount of a one-piece load being moved on to or off of the elevator cannot exceed 25% of the stated capacity of the elevator system. For example, although the capacity of the elevator may be 2,000 lbs (907 kg), the actual limit of a one-piece load is 500 lbs (226.75 kg). As well, the loading or unloading of the elevator is restricted to manual means or to a hand truck. In the event that a hand truck is used the weight of the equipment must be included as part of the 25% loading restriction.
Class B Loading
This class pertains to freight elevators that are intended for the transport of motor vehicles only, up to the stated capacity of the elevator system.
Class C Loading
NOTE: Class C loading is not permitted for accessibility lifts or for LULA elevators.
Class C1 Loading
This class allows industrial truck loading or unloading of the elevator system. The combined weight of the industrial truck and the load cannot exceed the stated capacity of the elevator. The loading device can remain on the elevator during operation.
Class C2 Loading
This class allows for the loading of the platform at 150% of the stated capacity of the elevator. In most cases, this allows for a one-piece load that equals the capacity of the elevator to be loaded with a forklift or motorized lift truck on to the platform of the elevator. The loading device must be removed prior to the operation of the elevator.
Class C3 Loading
This class allows for heavy concentration loading where the static load during loading and unloading does not exceed the rated load. The combined weight of the load and equipment must not exceed the stated capacity of the elevator system. In practice, Class C3 elevators are most often designated to support single piece loads equal to the capacity of the elevator.
Much of this information was taken from two web pages
www.delawareelevator.com & www.delta-elevator.com