Safety in use of Electrical testing equipments (rated voltages less than 650V) .......2

Design safety requirements for Test probes and leads :-

The test probes and leads used in conjunction with a voltmeter, multimeter, electrician’s test lamp or voltage indicator should be selected to prevent danger. Good test probes and leads will have the following:

(      (a)  The probes:-

(i) Have finger barriers or are shaped to guard against inadvertent hand contact with the live conductors under test;

(ii)  Are insulated to leave an exposed metal tip not exceeding 4 mm measured across any surface of the tip. Where practicable it is strongly recommended that this is reduced to 2 mm or less, or that spring loaded retractable screened probes are used;

(iii) Should have suitable high breaking capacity (hbc), sometimes known as hrc, fuse, or fuses, with a low current rating (usually not exceeding 500 mA), or a current-limiting resistor and a fuse.

 (b) The leads:

(i) Are adequately insulated (choice of insulating material may be influenced by the environment in which the leads are to be used);

(ii) Are coloured so that one lead can be easily distinguished from the other;

(iii) Are flexible and of sufficient capacity for the duty expected of them;

(iv) Are sheathed to protect against mechanical damage;

(v)  Are long enough for the purpose, while not too long so that they are clumsy or unwieldy;

(vi) Do not have accessible exposed conductors other than the probe tips, or have live conductors accessible to a person’s finger if a lead becomes detached from a probe, indicator or instrument when in use. The test lead or leads are held captive and sealed into the body of the voltage detector.