.svg)
Find out here ...
The following challenging questions were posed by Mr Ross Emerton of Doy Webster Partnership Ltd and answered at a specially convenend meeting of the Voltimum Switchgear Experts.
Dear Voltimum Team,
I have technical questions on switchgear & fusegear, which perhaps you could put to your switchgear & fusegear divisions for me.
I struggle to make myself happy with red/green colours when these are used on ACB on/off buttons and as status indication for switchfuse handles.
Firstly, the use of red & green on switch fuse assemblies seems (I'd hazard a guess universally) to use colours as follows:
Red = danger (meaning ON)
Green = safe = OFF.
Some ACB's I've seen seem have adopted the colour principle Red = stop = OFF.
I cannot recall which manufacturer(s) or badged product(s) this applies to, as only some use red for OFF. (Others use black, which is a preferred colour for OFF buttons.)
BSEN 60073 deals with basic & safety principles for man-machine interfaces, and the 1997 version I saw was definitely biased towards machines/processes rather than electrical distribution. Regarding colours, it favours Red = stop = OFF, but also Green = safe. Green shall not be used to indicate an OFF actuator. But this is primarily written for control buttons & indicator signals for machines/processes.
Against the premise that electrical distribution is different from operation of plant, My queries are:
1. Is there a BS or IEC standard corresponding to BSEN 60073 which deals with colours & symbols used in electrical distribution rather than operation of machinery?
Answer:
IEC60073 (BSEN60073) is a basic standard for us by product standards and committees. It is referred to by both installation, product and machine standards. The Voltimum Switchgear Experts Group is not aware of any specific standard on this subject for electrical distribution.
2. If not, who within the electrical industry is interested in rationalising the use of red & green for on/off on ACB's, fusegear and perhaps also on HV switchgear and on remote control stations?
Answer:
IEC Technical Committee 16 has considered this issue and, in view of extablished custom and practice in different countries and industries, now encourages the use of symbols and text to supplement or replace colours. Manufacturers of current switchgear products use 'O' to indicate off (open) and 'I' to indicate on (closed). ACB's, MCCB.s, MCB's, disconnectors and fused combination switches include symbols and/or text.
3. What are ACB and fusegear manufacturers (and switchboard fabricators) doing to ensure that 'red' & 'green' don't carry different meanings where ACB's & fuse-switches are used on the same LV panel?
Answer:
Members of the Voltimum Switchgear Experts Group who represent their organisations in standards committees will raise this subject with the relevant National, European and International Committees.
It's a difficult issue. I favour the colours used on most fusefear (red = ON) but perhaps that's because I have elec background.
If I was a control room operator, should I have to split my thinking - To turn pumps or fans on, press something and get a green signal for ON (running), but to turn on a part of the electrical distribution system, press something and perhaps see a closed switch symbol (coloured red for ON )?
Regards
Ross Emmerton
Doy Webster Partnership Ltd
Buckingham House, Churchfield Road, Walton-on-Thames, Surrey KT12 2TT
Tel: 01932 247713 Fax: 01932 222274