The requirements of the Electricity at Work Regulation 1989; British Standards No. 7671 and I.E.E. Guidance Note No. 3 2nd Edition Part 2

MES will provide a professional opinion of the condition of installations, by carrying out visual inspections and instrument tests of the parts of the Fixed Wiring Installation which are accessible to include the characteristics of supply at the origin of the installation.

Visual inspection.
C.P.C. continuity test.
Ring Circuit Continuity.
Insulation resistance test.
Polarity check.
Earth fault loop impedance test.
Prospective short circuit currents.
Operation of residual current devices.

CHARACTERISTICS OF SUPPLY (Reg. 313-01-01)

The characteristics of supply at the origin of the installation would be determined and would include the following:

Nominal voltage.
Nature of current and frequency.
Prospective short circuit current.
External earth fault loop impedance. (Ze)
Maximum demand in amps.
Type of rating of supplier's overcurrent protective device.

VISUAL INSPECTION (Reg. 731-01-02)

Inspection comprising careful scrutiny of every installation, where required, shall be carried out in accordance with the requirements of this chapter.

C.P.C. CONTINUITY (Reg. 713-02-01)

Protective conductors would be tested to verify that the conductors are Electrically sound and correctly connected.

This test should include: (a) All bonding conductors. (b) All earth visible clamps. (c) Metal accessories and equipment within a height of 3.5m above floor level. (d) The last lighting point on all lighting circuits.

RING CIRCUIT CONTINUITY (Reg 713-03-01)

An abbreviated ring circuit loop test would be carried out which will only ascertain that there is a ring on the outgoing cables from the distribution board and shall not identify a bridged ring.

INSULATION RESISTANCE (Reg. 713-04)

Insulation resistance tests between phase conductors, neutral and earth, and excepting any electronic equipment which may be damaged by the test, would be carried out to verify that the insulation of conductors, electrical accessories and equipment is satisfactory and that electrical conductors or protective conductors are not short circuited, or show a low resistance which would indicate deterioration in the insulation.

The test would be carried out with fuses in place, switches and circuit breakers closed and other equipment disconnected where appropriate.

If removal of lamps and the disconnection of current-using equipment is impracticable, local switches controlling such lamps and/or equipment would be open.

Insulation resistance tests would be carried out from all main switchboards and sub-main cables.

At distribution boards, insulation resistance tests would be carried out at the bus-bars and would include all final circuits connected to the distribution board, tested collectively.

POLARITY (Reg. 713-09-01)

A test of polarity would be carried out to verify that fuses and single pole control devices are connected in the phase conductor only.

EARTH FAULT LOOP IMPEDANCE (Reg. 713-10-01)

Measurements would be of the earth fault loop impedance at main intake, all switchboards, distribution boards and bus-bar systems.

MES will be pleased to survey and provide an estimate for this type of work.