Published: 16 April 2013
Category: Q&A
John Stokes asks this question, which concerns use of a plug/socket outlet for switching off in order to carry out mechanical maintenance work. It has been answered by the NICEIC (Theme – Regulations & Legislation):
This Q & A is one of thousands posted in our Technical Expertise area, and answered on a daily basis by our Voltimum Experts.
Question: What is the maximum amperage rating of a plug socket to be used for switching off for mechanical maintenance?
Regulation (Page 152) 537.3.2.6 states that it should not exceed 16A. However, Table 53.4 (Page 149) appears to state that a 32A plug socket (or greater than 32A) can be used for isolation purposes. The plug socket standard quoted in this table is to BS EN 60309. Is this standard for a socket that has a combined isolator function?
BS EN 60309-1 covers, I think, interlocked switches. Is there a difference between isolation and switching off for mechanical maintenance?
I found the above confusing, so there must be something I missed
Answer: The table does not give an indication for switching off for mechanical maintenance, which is a different concept to isolation. Isolation is the removal of electrical energy to reduce a shock risk when switching for mechanical maintenance, as it states, and live conductors may still be present. A plug and socket outlet would normally achieve both functions.
To see many more Q & A in Voltimum UK's Experts Area, please click on the link: www.voltimum.co.uk/consult.php?universe=consult.index.questions
Question: What is the maximum amperage rating of a plug socket to be used for switching off for mechanical maintenance?
Regulation (Page 152) 537.3.2.6 states that it should not exceed 16A. However, Table 53.4 (Page 149) appears to state that a 32A plug socket (or greater than 32A) can be used for isolation purposes. The plug socket standard quoted in this table is to BS EN 60309. Is this standard for a socket that has a combined isolator function?
BS EN 60309-1 covers, I think, interlocked switches. Is there a difference between isolation and switching off for mechanical maintenance?
I found the above confusing, so there must be something I missed
Answer: The table does not give an indication for switching off for mechanical maintenance, which is a different concept to isolation. Isolation is the removal of electrical energy to reduce a shock risk when switching for mechanical maintenance, as it states, and live conductors may still be present. A plug and socket outlet would normally achieve both functions.
To see many more Q & A in Voltimum UK's Experts Area, please click on the link: www.voltimum.co.uk/consult.php?universe=consult.index.questions