STSC Electrical Safety in Construction 4

Question 1

Under OSHA 29 CFR 1926.404, what is the maximum allowable ground fault current before a GFCI must trip?

Accepted Answer

5 milliamps

Answer

GFCIs are designed to trip at 4–6 milliamps, with 5 milliamps being the standard threshold cited by OSHA for construction site protection.

Question 2

Which condition makes an assured equipment grounding conductor program (AEGCP) an acceptable alternative to GFCIs on a construction site?

Accepted Answer

When a written program with required inspections and records is maintained

Answer

OSHA allows an AEGCP as a GFCI alternative only when the employer maintains a written program that includes required visual inspections and records of testing.

Question 3

A supervisor notices extension cords are being routed through doorways where doors pinch the cord. What is the primary hazard?

Accepted Answer

Insulation damage that can cause shock or fire

Answer

Pinching or crushing extension cord insulation can expose conductors, creating shock and fire hazards from arcing or direct contact.

Question 4

What is the minimum safe approach distance for unqualified workers near unguarded energized parts operating at 50 kV?

Accepted Answer

10 feet

Answer

OSHA 1926.416 requires unqualified workers to stay at least 10 feet away from unguarded energized lines or parts up to 50 kV.

Question 5

When must a construction supervisor verify overhead power line voltages before allowing equipment to operate nearby?

Accepted Answer

Always, before any work begins on site

Answer

OSHA requires determining line voltage before work begins so the correct safe approach distance can be established and maintained.

(STSC) Safety Trained Supervisor Construction Practice Test

(STSC) Safety Trained Supervisor Construction Practice Test

STSC Electrical Safety in Construction 4