Free DM Electrical Exam Exam Flashcards

Electrical Fitting Contracting, Dubai Municipality activity code 453014. It is classified as a secondary and supplementing contracting activity.

Either a bachelor's degree in electrical engineering with 2 years of experience, or an electrical technician diploma with 5 years of experience.

No. DEQ is Dubai Municipality's qualification system for technical staff. DEWA enrolment is a separate company service with its own licence, staff, credential, and experience documents.

230/400 V, 50 Hz, three-phase four-wire with a separate neutral and protective conductor. DEWA's regulations state a nominal voltage tolerance of plus or minus 10 percent.

The DEWA regulations prevail for installations supplied by DEWA. The latest applicable DEWA circulars and authority directions must also be checked before design or installation.

Before starting a new installation or an addition to an existing installation. Technical details must be submitted for review and prior approval through the applicable DEWA process.

DEWA requires the consumer to confirm supply availability before building construction. Early confirmation prevents a design from assuming a capacity or point of supply that DEWA has not approved.

DEWA. Its regulations generally provide one point of supply per plot or project unless DEWA approves another arrangement.

It must be readily accessible, clearly marked, and easy to identify. Where there is more than one supply, each main switch must indicate the section of the installation it controls.

Above 400 kW total connected load, although DEWA may require a substation at a lower load. The binding requirement is the one stated in the project's DEWA NOC or approval.

Connected load is the sum of equipment ratings. Maximum demand is the greatest load expected to operate at one time after applying justified demand and diversity assumptions.

Design current Ib must not exceed protective-device rating In, and In must not exceed the cable's corrected current-carrying capacity Iz: Ib ≤ In ≤ Iz.

Ambient temperature, grouping with other loaded circuits, thermal insulation, installation method, soil conditions for buried cables, and the number of loaded conductors.

Check load current, protective-device coordination, corrected ampacity, voltage drop, short-circuit thermal withstand, earth-fault performance, installation conditions, and any authority minimum size.

Multiply the tabulated mV/A/m value by design current and route length, then divide by 1,000 to obtain volts. Use the table and conductor temperature assumptions required by the applicable design standard.

Excessive drop can cause dim lighting, poor motor starting, overheating, malfunction, and unacceptable voltage at the load even when cable ampacity is adequate.

The prospective short-circuit current at its installation point. A device with insufficient breaking capacity may fail dangerously while interrupting a fault.

Whether a conductor, commonly a protective conductor, has enough cross-sectional area to withstand the fault current and disconnection time without thermal damage.

It must reflect the occupancy, equipment use, simultaneous operation, authority rules, and credible worst case. Unsupported diversity can undersize feeders, transformers, or switchgear.

Triplen harmonics from electronic loads can add in the neutral instead of cancelling. Neutral reduction is unsafe unless a calculation demonstrates adequate current capacity under the actual harmonic load.

At DEWA substations. DEWA's regulations say the neutral must not be earthed again anywhere in the consumer's installation.

It provides a separate low-impedance fault path for exposed conductive parts. It must remain separate from the neutral throughout the consumer installation.

The installation's earthing conductor, circuit protective conductors, and main protective-bonding conductors. This creates a common reference and a reliable fault-current path.

It connects relevant extraneous conductive parts to the earthing system so dangerous touch-voltage differences are limited during a fault.

A fault to exposed metal produces enough fault current or residual current to operate the protective device within the required time, limiting the duration of dangerous touch voltage.

No. An RCD detects residual current to earth; a fuse or circuit breaker protects against overload and short circuit. An RCBO combines both functions in one device.

Rated current, residual operating current, RCD type for the expected waveform, breaking or conditional short-circuit capacity, required disconnection time, and coordination with upstream devices.

To confirm that a line-to-earth fault will produce sufficient current for the protective device to disconnect within the required time.

Coordination so the device nearest a fault operates first while healthy upstream circuits remain energized. Compare time-current curves, settings, and manufacturer coordination data.

40 kA for 1 second, except for equipment protected by an upstream fuse. Equipment ratings and project-specific DEWA data must still be verified at the actual point of installation.

No. DEWA's regulations prohibit circuits from different distribution boards from being installed in a common conduit or trunking.

Segregation prevents unsafe contact, interference, and mistaken isolation. Use separate conduits or effective barriers for categories such as normal power, emergency, control, and extra-low-voltage circuits as required.

A maximum of five 13 A switched socket outlets outside the kitchen. The design must still meet load, cable, voltage-drop, and current circular requirements.

A maximum of ten 13 A switched socket outlets outside the kitchen, subject to the applicable installation and load rules.

Prior DEWA approval. The submission must show a safe changeover arrangement that prevents unintended connection or parallel operation with the DEWA supply.

Four poles for a three-phase supply and two poles for a single-phase supply, so the live conductors, including neutral as applicable, transfer together.

Mechanical and electrical interlocking prevents the sources from being connected together. Unapproved paralleling can backfeed the network and endanger workers and equipment.

The expected exposure to solids, dust, water, weather, cleaning, and access. Choose an enclosure suitable for the actual location rather than treating one IP code as universal.

Balancing reduces phase-current inequality, neutral loading, voltage imbalance, and inefficient use of feeder and transformer capacity.

It isolates all required live conductors, is clearly identified, readily accessible, suitably rated, and can be secured against inadvertent re-energization where necessary.

A thorough visual inspection. Confirm correct equipment, ratings, connections, conductor identification, barriers, access, labels, workmanship, and absence of visible damage.

The electrical contractor must inspect and test the entire installation, correct defects, and submit the required documents before requesting DEWA's inspection and final approval for connection.

That circuit protective conductors and bonding paths are electrically continuous from the relevant exposed or extraneous conductive parts back to the main earthing terminal.

500 V DC. Surge protective devices and other equipment that could be damaged or affect the result must be disconnected or handled as the applicable test procedure permits.

That line, neutral, and protective conductors are correctly connected, and that single-pole switches and protective devices interrupt the line conductor rather than the neutral.

The test button confirms the mechanism operates, while an instrument measures actual trip behavior. Neither test substitutes for verifying the protective conductor and fault path.

Prove the voltage indicator on a known source, test the isolated conductors, then prove the indicator again. This confirms the tester did not fail during the absence-of-voltage check.

Authorized workers need safe access for switching, inspection, maintenance, and emergency response. Storage, blocked doors, poor ventilation, or encroachment can create electrical and fire hazards.

Approved drawings and single-line diagrams, load schedules, equipment data, cable and protection calculations, test results, inspection certificates, and records of approved changes.

Circulars and later authority requirements can clarify or change details such as equipment, connection, metering, and submission rules. The current project approval governs when an older publication differs.