Installation Testing:Verification and Certification

Verification and Certification

New electrical installations and extensions to existing installations must be inspected and tested. This is done to ensure that all electrical equipment has been correctly selected, installed and interconnected in accordance with the ETCI National Rules for Electrical Installations. The rules state that two categories of tests must be carried out on an installation. One test is carried out prior to the installation being made live for the first time, and the other when the installation is live. Both tests must be carried out by competent persons using prescribed test equipment. They also must be carried out in a particular sequence. The results of the tests are recorded and a copy given to the installation owner.

Visual inspection

The quality of visual inspection is dependent on the experience and knowledge of the person carrying out the inspection. It is vitally important that this person understands the ETCI Rules.

Visual inspection should precede testing with instruments and must of course be prior to the installation being made live. It may be necessary to inspect some parts of an installation during the construction phase as these parts may be concealed later. A checklist for a Domestic Installation might read as follows:

Fixed Wiring

1. Correct type.

2. Correct voltage rating.

3. Correct current rating.

4. Correct colour coding.

5. Diversity correctly applied.

6. Permitted volt-drop not exceeded.

7. Protected against mechanical damage and abrasion.

8. Non-sheathed cables protected by enclosure in conduit, duct or trunking.

9. Not exposed to direct sunlight or, if so exposed, of a suitable type.

10. Correctly selected and installed for use on exterior walls etc.

11. Internal radii of bends in accordance with Annex 52B of the Rules.

12. Correctly supported in accordance with Annex 52B of the Rules.

13. Not used for connection of equipment which can be moved.

Flexible Cables and Cords

1. Correct type.

2. Correct voltage rating.

3. Correct current rating.

4. Correct colour coding.

5. Selected for resistance to damage by heat.

6. Cable coupler used for joints.

7. Final connections to fixed apparatus as short as possible.

8. Mass supported by pendants not exceeding values stated.

Terminations

1. All terminations enclosed.

2. Conductors doubled back where possible.

3. All strands securely clamped in terminals.

4. No damage to conductor.

5. Proper terminal used.

6. Braid / sheath cut back to identify core colour and provide flexibility at the termination.

7. Braid / sheath not removed outside of enclosure.

8. Bare protective conductors sleeved green / yellow.

9. Insulation not clamped in terminal.

10. Cable clamp / cord grip correctly used.

11. No mechanical strain on terminations, slack available

12. Terminations accessible for inspection, except as otherwise permitted.

13. Tightened sufficiently, mechanically and electrically sound.

14. Enclosure cover / lid fitted properly.

Lighting Switches

1. Adequate current rating.

2. Readily accessible.

3. Installed at correct height, e.g. centered at 1100 mm.

4. Labelled to indicate purpose, where this is not obvious.

5. Single-pole switches connected only in phase conductors.

6. Earthing of exposed metalwork, e.g. metal switch plate.

7. Protective conductor terminated in an earthing terminal.

8. Not installed in the incorrect zone in a shower or bathroom.

9. Not within 0.6m of the opening to a shower cubicle in a room other than a bathroom.

Ceiling Roses

1. Fixed in position.

2. Protective conductor connected to earthing terminal.

3. Phase terminal shrouded to prevent accidental contact.

4. Switch wires identified as live ( phase ) conductors.

5. Suitable for the weight suspended.

Trunking

1. Constructed of non-combustible insulating material.

2. Securely fixed and adequately protected against mechanical damage.

3. Permitted number of cables ( space factor 45% ) not exceeded.

4. Covers securely fixed.

5. Holes surrounding trunking made good to prevent spread of fire.

Protection

1. Distribution board correct and mounted in suitable location.

2. Earth Electrode connection accessible and correct.

3. Main switch fuse or MCB fitted.

4. Sockets for lighting controlled by a switch and protected by an RCD.

5. Socket circuits protected by an RCD. ( some exceptions )

6. Immersion heater circuit protected by an RCD.

7. Shower circuit protected by an RCD.

8. Box or other enclosure securely fixed.

9. Flush box, level with wall surface to ensure non-combustible enclosure.

10. No damage to cables by sharp edges, screw heads etc.

11. Switch within 2 metres of cooking appliance(s) and to one side.

Bonding

1. Main bonding conductor size correct.

2. Main bonding connections correct.

3. Main bonding complete.

4. Correct bonding clamps used

5. Local bonding correct.

Socket Outlets

1. Correct type.

2. Not less than 100 mm above the floor or working surface.

3. Correct polarity.

4. Earthing tail from metal box, to earthing terminal of socket outlet.

5. Not installed in a shower or bathroom.

6. Not within 0.6m of a shower cubicle in a room other than a bathroom.

Joint Boxes

1. Fixed in position.

2. Accessible for inspection.

3. Protected against mechanical damage.

4. Protective conductors correctly connected.

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