When working with ________/___________, it is essential to replace all covers or guards before energizing the equipment.

• A. Switches/Relays
• B. Starters/Contactors
• C. PCs/Sensors
• D. Motors/Gears

Answer: (B)

Guarding exposed energized parts before applying power is a safety rule for any equipment, but it’s especially critical with devices that actually switch motor current. Starters and contactors are the components in a motor control circuit that connect and disconnect power to a motor. They have live terminals and moving contacts inside a panel, and energizing with the covers or guards removed exposes you to electric shock and the possibility of an arc blast or flying debris if a fault occurs. Replacing all covers or guards seals those hazards and restores the protective barrier, making it safe to energize.

The other options don’t fit this specific safety emphasis as clearly. Relays and switches can be guarded, but the phrasing and typical maintenance scenario point to starters and contactors as the devices where people most often remove guards for inspection and must then replace them before re-energizing. PCs/sensors and motors/gears aren’t the standard focus of this exact instruction in most maintenance contexts.