NCCCO Load Moment Indicators and Safety Devices 3

Question 1

When an LMI system displays a load percentage of 95%, what should the crane operator do?

Accepted Answer

Slow all crane movements and prepare to stop operations

Answer

At 95% of rated capacity, the operator should slow movements and exercise extreme caution because small changes in configuration can quickly push the load past the rated limit.

Question 2

Which factor does an LMI system use along with load radius and boom angle to calculate rated capacity?

Accepted Answer

Boom length and configuration

Answer

Boom length and configuration (including jib attachments) are essential inputs that the LMI uses together with radius and angle to determine rated capacity from the load chart.

Question 3

An anti-two-block (ATB) device activates and stops hoist-up movement. What should the operator do first?

Accepted Answer

Lower the load or extend the boom to create clearance

Answer

The correct response is to lower the load or adjust the boom configuration to re-establish clearance between the hook block and the boom tip sheaves.

Question 4

Which of the following is NOT a standard input sensor for a crane LMI system?

Accepted Answer

Ambient air temperature sensor

Answer

Ambient air temperature is not a standard LMI input; standard sensors include boom angle, boom length, and load measurement via load cell or pressure transducers.

Question 5

A rated capacity limiter (RCL) differs from a basic LMI primarily because it:

Accepted Answer

Automatically stops crane motion when rated capacity is reached

Answer

An RCL not only indicates load percentage but also automatically intervenes to stop crane motions that would exceed rated capacity, whereas a basic LMI only provides warning.

NCCCO (National Commission for the Certification of Crane Operators) Practice Test

NCCCO (National Commission for the Certification of Crane Operators) Practice Test

NCCCO Load Moment Indicators and Safety Devices 3