Hi All,
When a switch opens only one leg of the mains to control power to
equipment should it be marked with the "l" and "O"?
Background:
Three different engineers from three different NRTLs indicated it is
permitted, two even required it. A different engineer for one of the
NRTLs and two other respected individuals indicate it is prohibited. It
will be interesting if members of this list will have the same 50/50
split or if there is a correct answer.
(single phase 100 to 240 VAC, 2A, 50-60 Hz, intended to be shipped US,
Canada, EU and generally internationally)
To help, IEC 60950 (1999), section 1.7.8.3 Symbols, is shown below.
Where symbols are used on or near controls, for example switches, push
button, etc., to indicate "ON" "OFF" conditions, they shall be the line
l for "ON" and the circle O for "OFF" (60417-1-IEC-5007 and
60417-1-IEC-5008). For push-push type switches the symbol {line in side
the circle} shall be used (60417-1-IEC-5010).
It is permitted to use the symbols O and l to indicate the "OFF" and
"ON" positions of any primary or secondary power switches, including
isolating switches.
A "STAND-BY" condition shall be indicated by the symbol {line breaking
the circle at the top} (60417-1-IEC-5009).
My bias was not included in the 50/50 statistics noted above but I
believe it is required.
Rick Linford
Regulatory Engineer
SonicWALL
-------------------------------------------
This message is from the IEEE EMC Society Product Safety
Technical Committee emc-pstc discussion list.
Visit our web site at: http://www.ewh.ieee.org/soc/emcs/pstc/
To cancel your subscription, send mail to:
[email protected]
with the single line:
unsubscribe emc-pstc
For help, send mail to the list administrators:
Michael Garretson: [email protected]
Dave Heald [email protected]
For policy questions, send mail to:
Richard Nute: [email protected]
Jim Bacher: [email protected]
All emc-pstc postings are archived and searchable on the web at:
http://www.rcic.com/ click on "Virtual Conference Hall,"
