Over the years the use of a red LED has been discouraged for use on
products because "Red" was reserved for situations "hazardous to an
operator". This resulted in the elimination of Red LEDs from keyboards
and other devices. Clause 1.7.8.2 of EN 60950 specifically allows Red
LEDs in areas where safety is not involved. As such I see no problem
using the device in conjunction with a user operated switch. I think
that was the intent of "permitting" red LEDs. Another point is that a
Red LED is much different than the use of a Red indicator light.

Regarding my last posting on shielded cables not being allowed in
Europe. I was misinformed. Apparently there are no longer any rules to
this effect. The beauty of this discussion group is that I learn
something every day.

Rick
[email protected]
        -----Original Message-----
        From:   Jim Eichner [SMTP:[email protected]]
        Sent:   Monday, January 26, 1998 11:06 AM
        To:     'EMC-PSTC - forum'
        Cc:     Rob Cameron; Jim Eichner
        Subject:        Red Indicators and EN60950

        Clause 1.7.8.2 of EN60950 says: 

        "Where safety is involved, colours of controls and indicators
shall
        comply with IEC73.  Where colours are used for functional
controls or
        indicators, any colour, including red, is permitted provided
that it is
        clear that safety is not involved".

        There has been a thread on this in the past so I looked it up at
RCIC
        and found that we never really talked about what exactly 950
means when
        it says "Where safety is involved" and "provided that it is
clear that
        safety is not involved".

        The situation I am considering is an LED used in conjunction
with a
        user-operable switch that is located in a control circuit (not a
true
        on-off switch) and controls the output of a DC-to-AC inverter.
When the
        switch is "on" the output of the inverter is enabled and 230Vac
is
        present on the output receptacle of the inverter.  Allowing the
user to
        know at a glance whether or not there is 230Vac present on the
output
        could be construed as a safety function.  On the other hand, the
user
        has no access to the 230Vac in terms of shock hazard (standard
Schuko
        outlet for example), so one could argue that safety is not a
function of
        this indicator.

        Q:  What are your opinions?  Can this LED be red and still
satisfy the
        intent of EN60950?

        The problem is a conflicting U.S. standard that insists on a red
        indicator.  We don't want to have to have a second version of
the
        control panel to cover both standards.  

        Thanks for your help.

        Regards,

        Jim Eichner
        Statpower Technologies Corporation
        [email protected]
        http://www.statpower.com
        Any opinions expressed are those of my invisible friend, who
really
        exists.  Honest.  

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