CHST - Construction Health and Safety Technician Electrical Safety and LOTO Questions and Answers

Question 1

An electrician is preparing to work on a 480-volt motor control center.
After shutting off the main breaker that supplies the MCC, what is the most critical next step they must perform before beginning work?

Accepted Answer

Verify the absence of voltage using a test instrument.

Answer

Notify affected employees that work is beginning.

Answer

Apply their personal lock and tag to the breaker.

Answer

Complete the Energized Electrical Work Permit.

Question 2

According to OSHA standards for construction (29 CFR 1926), what is the minimum clearance distance that must be maintained from overhead power lines rated 50kV or less for unqualified persons?

Accepted Answer

10 feet

Answer

5 feet

Answer

15 feet

Answer

20 feet

Question 3

Which of the following devices is considered an 'energy isolating device' as defined by OSHA's Lockout/Tagout standard?

Accepted Answer

A manually operated circuit breaker

Answer

An emergency stop push button

Answer

A control circuit selector switch

Answer

An interlock on a machine guard

Question 4

A construction crew is using a 120-volt portable generator to power cord-and-plug tools on a job site. To best protect workers from electric shock, the receptacles on the generator should be protected by a:

Accepted Answer

Ground-fault circuit-interrupter (GFCI)

Answer

Surge protector

Answer

Fuse rated for the tool's amperage

Answer

Double-insulated housing

Question 5

Under OSHA's Lockout/Tagout standard (29 CFR 1910.147), who is generally the only person authorized to remove a lock or tag from an energy isolating device?

Accepted Answer

The employee who initially applied the lock or tag.

Answer

The site supervisor for the work crew.

Answer

Any qualified electrician on site.

Answer

The competent person for the jobsite.

Question 6

Which of the following is a key requirement for an employee to be considered a 'qualified person' for performing electrical work, according to the OSHA 1926 construction standards?

Accepted Answer

Having training and experience to recognize and avoid the specific electrical hazards involved.

Answer

Holding a valid state electrician's license.

Answer

Having successfully completed a four-year apprenticeship.

Answer

Possessing a degree in electrical engineering.

An electrician is preparing to work on a 480-volt motor control center.After shutting off the main breaker that supplies the MCC, what is the most critical next step they must perform before beginning work?

An electrician is preparing to work on a 480-volt motor control center.
After shutting off the main breaker that supplies the MCC, what is the most critical next step they must perform before beginning work?