Morocco Equipment Technician flashcards

31 cards. Read the term and the definition here. The deck at the top of this page is optional.

Ohm's law

Voltage equals current multiplied by resistance (V = I × R). Combined with P = V × I, it allows any two known electrical quantities to determine the remaining ones in a DC or resistive circuit.

Three-phase power formula

For a balanced three-phase load, active power equals the square root of three multiplied by line voltage, line current and power factor: P = √3 × U × I × cos φ.

Power factor correction

Capacitor reactive power needed is Qc = P × (tan φ1 − tan φ2), where φ1 is the present angle and φ2 the target angle, usually chosen for a power factor near 0.95.

MCB trip curves

B curve trips magnetically at 3–5 times rated current, C at 5–10 times and D at 10–20 times. The choice depends on inrush current of the protected load.

Insulation resistance test

A DC test voltage, commonly 500 V or 1000 V, is applied between conductors and earth. A result below about 1 MΩ on a 400 V installation indicates degraded insulation.

Torque and power relation

Shaft torque in newton-metres equals 9550 times power in kilowatts divided by speed in revolutions per minute: T = 9550 × P / n.

Bearing bore code

In a bearing designation, the last two digits multiplied by five give the bore diameter in millimetres. For example, a 6205 bearing has a 25 mm bore.

Vibration fault signatures

A dominant 1× running speed component indicates unbalance, 2× indicates misalignment, and high-frequency broadband energy suggests rolling-element bearing defects.

Soft foot check

With a dial gauge on each foot, loosen one bolt at a time and read the movement. A value above about 0.05 mm is corrected with shims before shaft alignment.

Hydraulic power formula

Hydraulic power in kilowatts equals pressure in bar multiplied by flow in litres per minute, divided by 600. This gives the mechanical power delivered by the pump.

Cylinder retraction force

Retraction force equals pressure multiplied by the annulus area, which is the piston area minus the rod cross-section area. Extension force uses the full piston area.

Relief valve setting rule

The pressure relief valve is normally set 10 to 15 percent above the maximum working pressure of the circuit so it protects the pump without nuisance opening.

FRL unit order

In a pneumatic preparation unit, air passes through the filter first, then the pressure regulator, then the lubricator. The regulator sets downstream pressure.

Commissioning sequence

Mechanical completion, then alignment, then electrical insulation and continuity checks, then no-load run, then load test and finally performance acceptance against contractual values.

Laser shaft alignment

Two laser units and detectors measure offset and angularity between shafts. Correct soft foot first, then align within the manufacturer's tolerance, typically below 0.05 mm offset.

Predictive maintenance

Condition-based maintenance uses measured parameters such as vibration, temperature and oil analysis to schedule intervention before functional failure, instead of fixed time intervals.

Torque-to-yield bolts

These bolts are tightened past the elastic limit to a specified angle after reaching a torque value. They deform permanently and must be replaced, not reused.

Root cause analysis

The 5 Whys and Ishikawa fishbone methods separate symptoms from underlying causes. Corrective action must address the cause, otherwise the same failure recurs.

Single phasing effect

Loss of one supply phase to a three-phase motor leaves it running on two phases, drawing high current in the remaining windings and overheating rapidly, often tripping the overload.

4–20 mA live zero

The 4 mA minimum represents 0 percent of range, while 20 mA represents 100 percent. A reading of 0 mA therefore signals a broken wire or lost supply.

Three-wire RTD

A Pt100 sensor with three leads compensates for the resistance of the connecting cable, which is the main error source in two-wire measurement. It is common in industrial installations.

Calibration procedure

Compare the instrument with a traceable reference at 0, 25, 50, 75 and 100 percent of span, upscale and downscale, and record error and hysteresis against the acceptance criterion.

LOTO sequence

Notify, identify all energy sources, shut down, isolate, apply personal locks and tags, release stored energy, verify zero energy, work, then remove locks in reverse order.

Hierarchy of controls

Controls are applied in order: elimination, substitution, engineering controls, administrative controls and finally personal protective equipment, which is the least effective alone.

P&ID purpose

A piping and instrumentation diagram shows process equipment, piping, instruments and control loops using standard symbols. Instrument bubbles carry tag, function and loop number.

IP code meaning

The first digit of an IP rating indicates protection against solid objects and dust, the second against water. IP65 means dust tight and protected against water jets.

Work order content

A work order records equipment identification, reported fault, diagnosis, actions taken, parts used, time spent, tests performed and any remaining recommendations for the customer.

Objective fault reporting

Reports state measured values and observed facts separately from interpretation. Blame is avoided because the document is a technical record used for future diagnosis.

Cable sizing checks

A cable is adequate only when ampacity covers the protective device rating, voltage drop stays within limits, short-circuit withstand is met and the protective conductor is correctly sized.

Motor starting current

Direct-on-line starting draws five to eight times rated current. Star-delta connection reduces starting current and torque to one third of their direct-on-line values.

ISO 4406 cleanliness code

The code gives particle counts per millilitre in three size ranges. Hydraulic systems commonly require ISO 18/16/13 or cleaner, achieved with absolute-rated filters.