442A safety, work planning and commissioning practice questions.

Five free practice questions on safety, work planning and commissioning: block A of the Red Seal 442A Industrial Electrician exam, about 9 of its 100 questions. They are in the exam's format: four options, one correct answer. Answer each one before opening the explanation. No account, no email.

01The questions

1. Procedural · Performs lock-out and tag-out procedures

   A 13.8 kV vacuum circuit breaker has been tripped, racked out and moved to the maintenance bay, and its control power plug is disconnected. Its front indicator still shows the closing springs charged. What is done before work on its operating mechanism?

   1. Close then trip it with its manual buttons to discharge the springs.
   2. Ground its primary contacts with a portable ground set before starting.
   3. Pull the spring-charging motor's fuses so the springs cannot recharge.
   4. Fit a lockout device over the manual charging handle's socket.
   Show the answer

   A. Correct. A charged closing spring holds enough energy to slam the mechanism shut, with or without control power. Pressing the manual close button releases it (charging the opening springs), and the manual trip then releases those, leaving the breaker open with both indicators showing discharged before hands go into the mechanism.

   Why not the others

   B. Grounds deal with electrical energy, and a racked-out breaker in the shop has no source. The hazard here is mechanical energy stored in the charged closing spring, released by closing and then tripping the breaker manually.

   C. That prevents a new charge, and with the control plug out it is already prevented. The energy already stored in the charged closing spring is still there; it is released by closing and then tripping the breaker with its manual buttons.

   D. Blocking the charging handle stops someone adding energy by hand, but the closing spring is already charged. The stored energy is released by closing and then tripping the breaker with its manual buttons.

2. Procedural · Performs shutdown and startup procedures

   After a full plant shutdown, power is to be restored to a 600 V switchboard that feeds several MCCs. What is the usual sequence?

   1. Every feeder closed first, then the main, so the MCCs energize together.
   2. Main first with feeders open, check voltage, then feeders one at a time.
   3. Main first with feeders open, then all feeders closed at the same time.
   4. Main and all feeders closed, then voltage checked at each MCC in turn.
   Show the answer

   B. Correct. Energizing the bus alone lets voltage and phase rotation be checked with no load on it, and closing feeders one at a time keeps inrush down and shows at once which circuit is faulted if a breaker trips. Equipment with two-wire control that restarts by itself is cleared with operations before its feeder is closed.

   Why not the others

   A. Energizing every MCC at once stacks the inrush of all their transformers and any motors that restart, and if the main trips there is no telling which feeder caused it. Close the main alone, check it, then add feeders one at a time.

   C. The first step is right, but closing every feeder together brings back the combined inrush and hides which feeder carries a fault. Feeders are closed one at a time after the bus voltage is checked.

   D. Checking voltage after everything is on finds a problem only after it has been energized. The bus is checked with the feeders open, and then feeders are closed one at a time.

3. Recall · Uses rigging, hoisting and lifting equipment

   During a mobile crane lift in a plant yard, the signaller holds both arms out to the sides, palms down, and swings them back and forth horizontally. What does the signal mean?

   1. Emergency stop.
   2. Dog everything.
   3. Stop.
   4. Swing the boom.
   Show the answer

   A. Correct. Both arms extended, palms down, moved back and forth is the emergency stop: the operator stops every motion at once. The ordinary stop uses one arm in the same motion.

   Why not the others

   B. Dog everything (hold all motions) is given with the hands clasped together in front of the body. Both arms swung back and forth, palms down, is the emergency stop.

   C. The ordinary stop is one arm extended, palm down, moved back and forth. Using both arms is the emergency stop, which calls for every motion to halt at once.

   D. Swing is signalled with one arm extended, pointing a finger in the direction the boom is to swing. Both arms swung back and forth, palms down, is the emergency stop.

4. Procedural · Organizes materials and supplies

   A 2 500 kVA liquid-filled transformer arrives at a steel mill with an impact recorder attached. The recorder shows a 6 g shock in transit; the manufacturer's acceptance limit is 3 g. The tank looks undamaged. What should the receiver do?

   1. Note the reading on the delivery receipt and hold the unit for inspection.
   2. Sign for it as received, then report the reading to the supplier.
   3. Test its insulation resistance before signing, and accept it if it passes.
   4. Accept it, since the tank and bushings show no visible damage.
   Show the answer

   A. Correct. A shock above the manufacturer's limit can shift the core and coils inside a tank that looks perfect. The exception is written on the carrier's delivery receipt before signing, the supplier and carrier are notified, and the transformer is not set or energized until the manufacturer's inspection and tests clear it.

   Why not the others

   B. Signing the delivery receipt without noting the exception records the transformer as received in good order, which weakens any claim against the carrier. The reading is written on the receipt before signing and the unit held for inspection.

   C. An insulation-resistance test can pass with the core and coils shifted, because movement does not necessarily lower insulation resistance. The exception is noted on the receipt, and the manufacturer decides which inspection and tests clear the unit.

   D. Shipping damage to a transformer is often internal: shifted core or coils, loosened bracing or leads, none of which shows on the tank. The recorder reading is the evidence; note it on the receipt and hold the unit for inspection.

5. Procedural · Installs seismic restraint systems

   In a hospital plant room in a seismic zone, a dry-type transformer sits on open spring vibration isolators to keep its hum out of the structure. What provides the required seismic restraint?

   1. Neoprene pads under the springs to absorb the seismic motion.
   2. Restrained isolators or seismic snubbers that limit its travel.
   3. Anchor bolts through the isolator base plates into the slab.
   4. Stiffer springs, so that the transformer moves less in an earthquake.
   Show the answer

   B. Correct. Open springs let equipment bounce and slide, and in an earthquake they can amplify its motion until it walks off the isolators. Restrained spring isolators, or snubbers set with a small gap, leave the vibration isolation working in normal service and stop the unit's travel in an earthquake, anchored as the seismic design shows.

   Why not the others

   A. Neoprene pads absorb high-frequency noise; they do not hold equipment in place during an earthquake. Restrained isolators or seismic snubbers are needed to limit its travel.

   C. Anchoring the base plates holds the isolators down, but the springs still let the transformer above them bounce and slide off. The restraint must act on the equipment itself, through restrained isolators or snubbers.

   D. Stiffer springs pass more of the transformer's vibration into the building, defeating the reason for the isolators, and they still leave the unit unrestrained. Restrained isolators or snubbers limit its travel.

02Answer key

03What block A covers

Block A is the groundwork behind every industrial job: lockout and tagout, PPE and arc-rated clothing, combustible dust and hazardous locations, hand tools, aerial work platforms and crane lifts near power lines, reading P&IDs and drawings, receiving and storing equipment, anchors and seismic restraints, and the commissioning, shutdown, start-up and decommissioning of electrical systems.

The Red Seal Occupational Standard names this block “Performs common occupational skills”. It carries 9% of the exam, about 9 of the 100 questions, split across six tasks. The share column is each task's weight within the block, as the standard publishes it.

04What the questions turn on

New locks go on first

When a locked-out job runs into the next shift, the incoming workers apply their own locks before the outgoing workers remove theirs. The equipment is never left without a personal lock, and the status of every isolation point is logged.

Test every pull-cord on its own

Pull-cord emergency stops wired in series to a safety relay are still separate safety devices. Each cord is pulled in turn to prove the belt stops and the switch latches, so the conveyor cannot restart until the switch is reset at the switch.

Inner colour showing retires the tool

On a two-layer insulated hand tool, the contrasting inner colour is a wear indicator. Once it shows through a nick, the voltage rating can no longer be relied on, and the tool is tagged and taken out of service.

Heaters keep idle gear dry

Space heaters hold the inside of switchgear a few degrees above the outside air so moisture does not condense on the bus and insulators. During storage or an outage they need a separate supply, and wet gear is dried and insulation tested before energizing.

05The other blocks

The 442A exam has six blocks. Each has its own page of free questions:

The 442A Industrial Electrician practice exam page describes the full question bank. How these questions are written and checked: how our questions are made. Found a mistake? Tell us and we will fix it.