Initial verification (inspection and testing) is used to ensure that electrical installations are safe before being put into service.
610.1 — Every installation shall, during erection and on completion before being put into service, be inspected and tested to verify, so far as is reasonably practicable, that the requirements of the Regulations have been met.
Precautions shall be taken to avoid danger to persons and damage to property and installed equipment during the inspection and testing.
Three principle criteria for an electrical installation which informs initial verification and inspection:
1. compliance with BS 7671, particularly in reference to: a. The Fundamental Principles (Section 131) b. The general characteristics (Sectiosn 311 and
313)
c. Information required by 514.9.1 2. compliance with the project specification
(commissioning) 3. that it is safe to use.
Avoid Danger to Persons
• Have you checked to see if any essential services are supplied from the board e.g. emergency lighting, fire alarms, life-support equipment, UPS systems, gas
• Have you discharged any capacitors? • Is the test equipment appropriate for the
environment, e.g. intrinsically Safe?
• Are you using long test leads that could cause people to trip over?
• Have you informed people of the dangers?
Avoid Damage to Property
• Is there an RCD in the circuit? • Are there computers on line?
• Is there electronic equipment in the circuit?
• Could gaskets be damaged when removing covers? • Are all the loads disconnected?
• Is there any equipment or processes which may be damaged if disconnected for long periods of time? • Is there any essential equipment which cannot be
turned off?
610.5 - The verification shall be made by a skilled person, or persons, competent in such work..
This replaces the reference to competent person.
611 — Inspection
611.1 — Inspection shall precede testing and shall normally be done with that part of the installation under inspection disconnected from the supply.
611.2— The inspection shall be made to verify that the installed electrical equipment is:
• In compliance with Section 511
(this may be ascertained by mark or by certification furnished by the installer or by the manufacturer), and
• Correctly selected and erected in accordance with the Regulations, and
• Not visibly damaged or defective so as to impair safety.
611.3 — The inspection shall include at least the checking of the following items where relevant, including as appropriate all particular requirements for special installations or
locations (Part 7).
• Connection of conductors • Identification of conductors
• Routing of cables in safe zones or protection against mechanical damage, in compliance with Section 522
• Selection of conductors for current-carrying capacity and voltage drop, in accordance with the design
• Connection of single-pole devices for protection or switching in phase conductors only
• Correct connection of accessories and equipment • Presence of fire barriers, suitable seals and
protection against thermal effects
• Methods of protection against electric shock covered in detail earlier in this course.
Summary of Initial verification
1. Precedes testing and the installation being inspected should be disconnected from the supply.
2. Is necessary before any new installation work or alterations and additions to existing installations are permanently connected to the supply.
3. Confirms that equipment:
4. Complies with UK or European standards (BS, BS EN)
5. Is correctly selected and erected, and
6. Is not damaged or defective as to impair safety. A Schedule of items inspected should be completed to ensure all relevant requirements have been met.
612 — Testing
This section details the required tests to be for initial verification. The tests should be carried out in a prescribed sequence, some prior to the circuits being energized. 612.1
The tests of Regulations 612.2 to 13, where relevant, shall be carried out and the results compared with relevant criteria. Measuring instruments and monitoring equipment and methods shall be chosen in accordance with the relevant parts of BS EN 61557. If other measuring equipment is used, it shall provide no less degree of performance and safety. When undertaking testing in a potentially explosive atmosphere, appropriate safety precautions in accordance with BS EN 60079-17 and BS EN 61241-17 are necessary. The tests of Regulations 612.2 to 6, where relevant, shall be carried out in that order before the installation is energized. Where the installation incorporates an earth electrode, the test of Regulation 612.7 shall also be carried out before the installation is energized.
If any test indicates a failure to comply, that test and any preceding test, the results of which may have been
influenced by the fault indicated, shall be repeated after the fault has been rectified.
Before the supply is energized – Dead tests 612.2 Continuity of Conductors
612.2.2 Continuity of ring final circuit conductors 612.3 Insulation resistance
Fig. 70 Single phase insulation resistance
612.4 Protection by SELV, PELV or Electrical separation 612.4.1 Protection by SELV
612.4.2 Protection byPELV
612.4.3 Protection by Electrical separation 612.4.4 FELV
612.4.5 Basic protection by barriers and enclosures provided during erection
612.5 Insulation resistance/impedance of floors and walls 612.6 Polarity
Fig. 71 Polarity test (part)
Fig. 72 Earth electrode test (one of many) With the electrical supply connected 612.8 Protection by ADS
612.9 Earth fault loop impedance 612.10 Additional Protection(RCDs) 612.11 Prospective Fault current
612.12 Check for Phase Sequence (multi-phase supply) 612.13 Functional Testing
preceding test, the results of which may have been
influenced by the fault indicated, shall be repeated after the fault has been rectified.
It is recommended you become familiar with each of the tests describe in Section 612, and to be prepared to refer to Table 61.
Ch62 - Periodic Inspection & Testing
Periodic testing is not the same as testing as part of an Initial Verification. The same range and level of testing is not required and in the majority of cases will not be possibleThe two Regulations which you should pay attention to are: 621.1 — Where required, periodic inspection and testing of every electrical installation shall be carried out in accordance with regulations 621.2 to 621.5 to determine, as is reasonably practical, whether the installation is in a satisfactory
condition for continued service.
621.2 — Inspection comprising careful scrutiny of the installation shall be carried out without dismantling or with partial dismantling as required, together with the
appropriate tests of Chapter 61.
Such inspection and testing shall provide, so far as is reasonably practicable, for:
• The safety of persons and livestock against the effects of electric shock and burns.
• Confirmation that the installation is not damaged or deteriorated so as to impair safety, and
• The identification of installation defects and non- compliance with the requirements of the
Regulations which may give rise to danger. 621.3— Precautions shall be taken to ensure that the inspection and testing does not cause danger to persons or livestock and does not cause damage to property and equipment even if the circuit is defective.
621.5— Periodic inspection and testing shall be undertaken by a competent person
622 — Frequency of Inspection and Testing
622.1 — The frequency of periodic inspection and testing of an installation shall be determined having regard to the type of installation, its use and operation, the frequency and quality of maintenance and the external influences to which it is subjected.
The results and recommendations of the previous report if any shall be taken into account.
622.2 — In the case of an installation under effective management systemfor preventive maintenance in normal use, periodic inspection and testing may be replaced by an adequate regime of continuous monitoring and maintenance of the installation by skilled persons, competent in such work Appropriate records shall be kept.