220-1202 Practice Question: A small office has a UPS that emits a loud…

Answer analysis

Option-by-option breakdown

For each option: why learners choose it and why it is or isn't the right answer here.

• ✗

  Replace the battery while the UPS is still plugged in.

  Why it's wrong here

  A UPS, especially when plugged in, maintains a live electrical circuit, often with high DC voltage from the battery bank and AC voltage from the utility input. Replacing a battery in this state poses significant risks of electrical shock, short circuits, and potential fire, particularly if the failing battery is already overheating or swelling. Always de-energize the unit completely by unplugging it from the wall and disconnecting all loads before attempting any internal maintenance or battery replacement.

• ✓

  Unplug the UPS and move it to an open, well-ventilated area.

  Why this is correct

  An overheating UPS, especially one emitting a burning smell, indicates a critical internal fault, most commonly a failing battery experiencing thermal runaway. Unplugging the unit immediately removes all power input, preventing further charging or discharge that could exacerbate the thermal event. Moving it to a well-ventilated area helps dissipate any hazardous fumes or heat, significantly mitigating the risk of fire, explosion, or inhalation exposure to toxic gases.

• ✗

  Reset the UPS by pressing the power button.

  Why it's wrong here

  Pressing the power button to reset a UPS primarily cycles its internal control logic or clears minor software-related fault states. However, it does not address a physical hardware failure like an overheating or failing battery, which is the likely cause of a burning smell. Attempting a reset could potentially re-engage the charging circuit, further stressing the compromised battery and accelerating thermal runaway, thereby increasing the risk of fire or explosion.

• ✗

  Spray the UPS with a fire extinguisher.

  Why it's wrong here

  Applying a fire extinguisher, particularly a dry chemical (ABC) or CO2 type, to an electronic device that is merely overheating or emitting a smell but not actively on fire is premature and can cause extensive damage. Dry chemical residues are corrosive and extremely difficult to clean from sensitive electronics, while CO2 can cause extreme cold shock, potentially damaging internal components. Extinguishers should be reserved for active fires, and the primary action for an overheating device is to remove its power source safely.

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