NCCCO Maintenance and Troubleshooting 4

Question 1

When inspecting wire rope, what condition requires immediate removal from service?

Accepted Answer

Six randomly distributed broken wires in one rope lay

Answer

Six or more randomly distributed broken wires in one rope lay is a disqualifying condition per ASME B30.2 standards.

Question 2

A crane's load line sheave shows excessive groove wear. What is the primary risk if it continues in service?

Accepted Answer

Increased rope wear and potential wire damage

Answer

Worn sheave grooves cause accelerated wire rope wear by creating high contact stress on individual wires.

Question 3

What does a milky or foamy appearance in hydraulic fluid indicate?

Accepted Answer

Water contamination

Answer

Milky or foamy hydraulic fluid indicates water contamination, which reduces lubrication and can cause cavitation.

Question 4

During a functional test after maintenance, the crane's swing brake does not hold on a slope. What is the most likely cause?

Accepted Answer

Worn or improperly adjusted brake linings

Answer

Worn or maladjusted brake linings reduce clamping force, preventing the swing brake from holding the superstructure on a grade.

Question 5

Which lubrication point on a lattice boom crane requires grease at the most frequent interval?

Accepted Answer

Boom pin connections

Answer

Boom pin connections experience continuous dynamic loading and must be greased most frequently to prevent galling and wear.

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