Past ExamsRwanda ICT preparation

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Maintenance

15 free questions with worked answers, and 144 more in the full bank.

Free questions

A maintenance team replaces the air filters on HVAC rooftop units every three months, regardless of their condition. What type of maintenance strategy is this?
1 mark · Easy
A facility uses ultrasonic sensors to monitor the high-frequency acoustic emissions of roller bearings on a critical conveyor. When the acoustic signature crosses a threshold, a work order is generated. What strategy is this?
3 marks · Medium
A technician repairing a failed boiler feed pump decides to analyze why the seal failed. They discover the baseplate is vibrating due to improper grouting, so they regrout the baseplate to prevent future seal failures. What strategy does this represent?
4 marks · Hard
A technician is troubleshooting a PLC ladder logic program. A physical emergency stop button is wired normally closed (NC) in the field. In the ladder logic, what instruction should be used to allow the machine to run when the E-stop is NOT pressed?
3 marks · Medium
A PLC controls a pneumatic cylinder. The sequence stops mid-cycle. The technician forces the output bit ON in the PLC software, and the cylinder moves. What does this confirm?
4 marks · Hard
A pressure transmitter operates on a standard 4-20mA loop. What is the primary advantage of using a "live zero" (4mA) instead of 0-20mA?
1 mark · Easy
A level transmitter is scaled from 0 to 100 inches. The loop current is currently measuring 12mA. What is the actual water level in the tank?
3 marks · Medium
A 4-20mA loop is wired in series through a transmitter, a PLC input card (250 ohm resistor), and a chart recorder (250 ohm resistor). The power supply is 24VDC. The transmitter requires a minimum of 12VDC to operate. Will this loop function at 20mA?
4 marks · Hard
A technician calibrates a pH probe. They record the readings before making any adjustments, then calibrate the device, and record the readings again. What is this documentation standard called?
3 marks · Medium
A temperature transmitter is calibrated for 0°C to 200°C. During a 5-point calibration, the tech notes that the output is perfectly accurate going up the scale, but reads consistently 2 degrees high when coming down the scale. What physical phenomenon is the instrument exhibiting?
4 marks · Hard
A vibration analyst reviews an FFT spectrum on a large centrifugal fan running at 1800 RPM (30 Hz). There is a massive spike exactly at 1X running speed (30 Hz). What is the most likely mechanical fault?
3 marks · Medium
An induction motor driving a pump via a flexible coupling shows high vibration at 1X and 2X turning speed, accompanied by a 180-degree phase shift across the coupling. What is the definitive diagnosis?
4 marks · Hard
A maintenance electrician scans a 3-phase motor starter with an infrared camera. Phase A is 45°C, Phase B is 46°C, and Phase C is 95°C. What is the most likely cause of this discrepancy?
1 mark · Easy
When conducting an outdoor thermography inspection of a substation on a bright sunny day, the technician notes that all the ceramic insulators on the east side appear extremely hot. What must the technician consider?
3 marks · Medium
A process engineer wants to change the alarm setpoint of a high-pressure reactor from 500 psi to 550 psi to prevent nuisance trips. The vessel is rated for 600 psi. What formal process MUST be followed before the technician makes the change in the PLC?
3 marks · Medium

More Maintenance questions (page 1 of 3)

Answers and explanations are in the full bank.