RE: Wiring - Single faults

[Gregg Kervill]

Hi David,

Please have a look at the free On-Line training courses that are on our web
site at www.test4safety.com, follow the E-Learning Solutions link and
download ES/2001/INTPWRSUP/D 007

The solution is there.

Best regards

Gregg

PS - we are tidying up the material so it may change over the next few
weeks.


We would appreciate comments.

Thanks

G

PLEASE NOTE NEW NUMBERS
P.O. Box 310, Reedville,
Virginia 22539  USA

Phone: (804) 453-3141
Fax: (804) 453-9039
Web: www.test4safety.com

  -Original Message-
  From: owner-emc-p...@majordomo.ieee.org
[mailto:owner-emc-p...@majordomo.ieee.org]On Behalf Of k3row
  Sent: Tuesday, November 13, 2001 6:26 PM
  To: emc-p...@majordomo.ieee.org
  Subject: Wiring - Single faults


  As a military radar systems engineer I deal with various safety issues
associated with aircraft radar systems.  However, I have recently been
looking at the safety of some associated benign environment test equipment
comprising (at least in the context of safety) various simple 230v standard
mains power commercial components. The connection mechanism for these
internal components are, in some cases, tight push fit spade terminal type
connections. The free terminal at the end of the connection wire is
insulated with a recessed inner. The wire connection to this free spade
connector is also covered with a heatshrink sleeve which provides additional
insulation and containment for the wire. Thus if the wire joint somehow
breaks, the wire remains insulated and held in place. This then provides
adequate single fault containment as far as, say, wire breakage at the wire
joint is concerned.

  Here is my very trivial question.

  What I can't get clear in my mind is this: If I wish, I can, of course,
just completely pull the free connector off the component terminal. Is the
complete disconnection of the spade terminal pair, with the free end now
hanging loose, regarded as a single fault to be dealt with, or is this
regarded as too gross to be considered a single fault?

  Any advice would be appreciated

  Regards

  Dave Palmer

Wiring - Single faults

[k3row]

As a military radar systems engineer I deal with various safety issues 
associated with aircraft radar systems.  However, I have recently been looking 
at the safety of some associated benign environment test equipment comprising 
(at least in the context of safety) various simple 230v standard mains power 
commercial components. The connection mechanism for these internal components 
are, in some cases, tight push fit spade terminal type connections. The free 
terminal at the end of the connection wire is insulated with a recessed inner. 
The wire connection to this free spade connector is also covered with a 
heatshrink sleeve which provides additional insulation and containment for the 
wire. Thus if the wire joint somehow breaks, the wire remains insulated and 
held in place. This then provides adequate single fault containment as far as, 
say, wire breakage at the wire joint is concerned.

Here is my very trivial question.

What I can't get clear in my mind is this: If I wish, I can, of course, just 
completely pull the free connector off the component terminal. Is the 
complete disconnection of the spade terminal pair, with the free end now 
hanging loose, regarded as a single fault to be dealt with, or is this regarded 
as too gross to be considered a single fault?

Any advice would be appreciated
 
Regards

Dave Palmer