By Grant Seeman – ECA(SA) National Technical Advisor
A practical series on the four inspection questions and 15 tests in SANS 10142-1
Part 4: Correct and permanent marking and labelling
The fourth inspection question reads:
“Circuits, fuses, switches, terminals, earth leakage units, circuit-breakers, distribution boards are correctly and permanently marked or labelled.”
Clause 8.5.2 requires this statement to be confirmed with a “Yes”. A “No” answer prevents the issuing of the test report.
This inspection is not simply about checking whether labels are present. The labels and markings must actually identify the installation correctly. Clause 8.5.2 also specifically requires attention to installations where circuit-breakers are used in series-connected or cascaded systems.
Why is this important?
Correct labelling allows a user, electrician or other person working on the installation to identify the correct circuit, protective device or source without guessing.
An incorrect label can be more dangerous than no label at all. If a circuit-breaker marked “geyser” actually controls socket-outlets, somebody could isolate the wrong circuit and believe that equipment is safe to work on when it is still live.
Clause 4.2 requires notices, labels and rating plates required by SANS 10142-1 to be durable, not removable except by deliberate action, and to have inscriptions that are legible and indelible.
What must be confirmed?
The registered person must establish that:
• The labels and markings required by SANS 10142-1 are present.
• The labels correctly identify the circuits or equipment to which they refer.
• Labels are permanent, legible and suitable for their purpose.
• Incoming and outgoing circuits of distribution boards are identified where their purpose is not obvious.
• Main and sub-main switch-disconnectors are correctly labelled.
• Circuit-breakers identify the circuit or appliance they control where required.
• Required warning labels are fitted.
• Alternative supplies and other special supply arrangements are properly identified.
• Existing labels still match the installation after alterations or additions.
Clause 6.6.1.19 requires permanent labelling to identify all incoming and outgoing circuits of a distribution board unless their purpose is obvious.
How is the inspection carried out?
Start at each distribution board and compare the labels with the installation itself. Do not simply read the label and assume that it is correct. Where necessary, safely operate or trace the circuit to confirm what the circuit-breaker actually controls.
Clause 6.8.2.2 requires each circuit-breaker to be labelled to show the circuit or appliance it controls, except where the circuit-breaker is mounted next to the appliance or socket-outlet that it controls.
Also check the warning labels required at distribution boards. Clause 6.6.1.20 includes, where applicable:
• Where the distribution board is supplied from.
• The minimum fault-current rating of switchgear where the short-circuit rating exceeds 3 kA.
• The required warning for a series-connected or cascaded system.
• The busbar current rating where it exceeds 100 A.
• The position of the readily accessible earthing terminal provided for bonding other services.
Labelling does not stop at the distribution board. Fuse-protected circuits must be marked with their maximum permissible current rating.
Socket-outlet circuits require warning labels where the earth leakage tripping current is above 30 mA, where they are supplied from a safety supply, or where they are on dimmer control.
Where more than one circuit enters an enclosure, a warning label is required. Where more than one phase of a lighting circuit enters an enclosure, the standard requires either the prescribed voltage warning inside the enclosure or suitable barriers between the phase terminals.
Alternative supplies also require specific notices. Where an alternative supply is connected, a notice must be displayed at the main switch, with additional identification required at affected distribution boards where applicable.
Common mistakes
Common mistakes include:
• Labels that no longer correspond with the circuits after alterations.
• Circuit-breakers with missing or incorrect circuit descriptions.
• Using temporary paper, masking tape or markings that fade or fall off.
• Failing to identify an alternative source of supply.
• Missing warning labels on distribution boards.
• Failing to identify a cascaded protection arrangement.
• Missing warnings where more than one circuit or phase enters an enclosure.
• Assuming that because a label is fitted, it must be correct.
What if the result is unacceptable?
Incorrect labels must be corrected, missing labels fitted and outdated labels replaced. Where there is uncertainty, the circuit should be properly traced and identified before the inspection item can be marked “Yes”.
Regulation 9(3) of the Electrical Installation Regulations requires the registered person to refuse to issue the Certificate of Compliance until the fault or defect has been rectified.
Practical tip
Do not ask only:
“Is it labelled?”
Ask:
“If I operate this device, does the label tell me exactly what I am actually switching or isolating?”
Key takeaway
Correct labelling is part of electrical safety. A label must not only be present — it must be correct, permanent, legible and relevant to the installation as it actually exists.
