On Fri, 5 Dec 2008 05:59:09 -0800 (PST) someone who may be
wrote this:-

I see a light through the plastic socket cover and sometimes see the
spark through the gap the switch sits in.

What is the rating of this fire. 3kW?

With any reasonably high power electrical equipment there will often
be a visible spark at the switchgear when it is switched off [1]
[2]. This is generally nothing to worry about. However, if the
heater has its own controls I suggest using them to switch the
heater on and off. The spark will still be there, but it may not be
visible (sometimes it is more visible in a heater though, there is
not one answer to your questions).

The sparks (and arcs) on large switchgear can be very impressive
indeed, there are films on the web.

[1] with AC electricity there are times when the current is so close
to zero that there is no spark. Whether you operate the switch at
that time is a matter of luck.

[2] the spark is often still there even if it is not visible.


--
David Hansen, Edinburgh
I will *always* explain revoked encryption keys, unless RIP prevents me
http://www.opsi.gov.uk/acts/acts2000/00023--e.htm#54