Iran Nezam Electrical Supervision Exam key terms

The formal stamp and signature a licensed electrical supervisor places on design drawings and execution reports to certify conformity with approved standards, without which the installation may not legally be energized.

A written supervisory document in which the licensed engineer records the checks performed on calculations, single-line diagrams, and equipment selection, and states whether the design is approved, conditionally approved, or rejected.

The final drawing set and equipment records updated to reflect the installation as actually constructed, handed to the owner and used by the supervisor to confirm that field changes were technically acceptable.

The licensed engineer whose name appears on the permit and who carries legal responsibility for the electrical work's compliance, including duty to inspect, to order correction, and to report serious hazards.

A written instruction by the supervising engineer halting electrical work that endangers life or property or departs from approved drawings, remaining in force until the defect is corrected and re-inspected.

A itemized record of incomplete or nonconforming work identified at inspection, each item tracked to closure before provisional acceptance and energization of the installation.

The luminous flux arriving per unit area on a working surface, expressed in lux, used to select lighting levels for offices, corridors, workshops, and escape routes according to the room's task.

A multiplier below one applied to calculated illuminance to account for lamp lumen depreciation and dirt accumulation on luminaires, ensuring maintained illuminance stays adequate between cleaning cycles.

The ratio of luminous flux produced by a lamp to the electrical power it consumes, expressed in lumens per watt, and a primary input when comparing lamp technologies for an energy-compliant design.

The maximum permitted connected lighting or total electrical load per unit of floor area, used by the national code to cap energy use and checked by the supervisor against the lighting layout.

The reduction in voltage along a circuit caused by conductor impedance under load, calculated from current, length, and conductor resistance and reactance, and kept within code limits at the furthest outlet.

The ratio of the maximum demand over a period to the total connected load, applied to grouped loads such as receptacles or ranges so that feeders and service equipment are not oversized.

The ratio of the sum of individual peak demands to the coincident maximum demand of the whole installation, used to size upstream transformers and main feeders realistically.

A tabulation of every circuit and connected load with its demand factor, current, breaker rating, and cable size, forming the basis for panel, feeder, and service sizing.

A drawing of a distribution board showing circuit numbers, phase allocation, breaker ratings, connected loads, and spare ways, used to balance phases and to plan future expansion.

The distribution of single-phase loads among the phases of a three-phase system so that phase currents and neutral current remain acceptably close, reducing losses and voltage unbalance.

The maximum current a conductor can carry continuously under stated installation conditions without exceeding its rated temperature, determined from tables and then adjusted for ambient temperature and grouping.

A multiplier below one applied to tabulated current-carrying capacity to account for high ambient temperature, grouped cables, thermal insulation, or buried depth, reducing the permissible continuous current.

The correction applied when several loaded circuits run together in one conduit, trunking, or duct, because mutual heating prevents each cable from dissipating heat as if installed alone.

The nominal metallic area of a conductor in square millimetres, selected from ampacity, voltage drop, short-circuit withstand, and mechanical strength requirements rather than current alone.

The proportion of a raceway's internal cross-section occupied by conductors, limited so that cables can be pulled without damage and heat can dissipate during operation.

A rigid metallic or non-metallic support system carrying cables in an accessible route, requiring consideration of fill, support spacing, fire barriers at wall penetrations, and bonding of sections.

The deliberate connection of exposed conductive parts, extraneous conductive parts, and the main earthing terminal so that dangerous potential differences cannot develop between them during a fault.

The resistance between a buried earth electrode and remote earth, measured to confirm that fault current has a low-impedance path and that touch voltages remain safe.

The total impedance of the path taken by fault current from the source through the live conductor, the fault, and the protective conductor back to the source, governing disconnection time.

A protective device that trips when the vector sum of currents in the live conductors indicates earth leakage above its rated residual operating current, providing additional protection against electric shock.

A breaker or fuse that interrupts current above its rating, and which must be coordinated with conductor ampacity so that it protects the cable against overload and short circuit.

The coordination of protective devices so that the device nearest a fault operates first, leaving upstream devices closed and limiting the outage to the smallest possible part of the installation.

The maximum prospective fault current a device or assembly can safely interrupt or withstand for a stated time, which must exceed the calculated fault level at its point of installation.

A tested assembly restoring the fire resistance of a wall or floor where cables, conduits, or trays pass through it, installed and inspected as part of fire protection supervision.

Battery-backed or centrally supplied lighting that maintains escape route illumination and exit signage for a defined duration when normal supply fails, subject to periodic discharge testing.

A defined area of a building monitored by a detection circuit, arranged so that a fire can be located quickly and so that alarm and evacuation logic act on the correct part of the premises.

A circuit designed so that its energy, including stored energy in capacitance and inductance, cannot ignite a flammable atmosphere under normal or specified fault conditions in a hazardous area.

The division of a space into zones according to the likelihood and duration of a flammable gas, vapour, or dust atmosphere, which then determines the permitted equipment protection concept.

An enclosure designed either to contain an internal explosion without transmitting flame or to prevent ignition by limiting surface temperature, breathing, and spark energy, marked with its protection concept and gas group.

A system combining rectifier, battery, and inverter to supply loads without interruption during mains failure, with transfer time and autonomy matched to the criticality of the connected equipment.

A standardized hierarchy of copper and fibre cabling linking work areas, telecommunications rooms, and equipment rooms, with separation from power cabling to control interference and fire spread.

Power conversion equipment synchronizing a renewable source with the utility supply, requiring anti-islanding protection, visible isolation, and coordination with the main protective devices.

An engineering analysis of time-current characteristics of fuses and breakers confirming that ratings, settings, and selectivity achieve safe disconnection while minimizing unnecessary outages.