Joe,
You might be able to persuade the UK officials to go along with the
IEC 950 4th edition version. My understanding is that the CENELEC
EN 4th edition version should be published shortly.
Thus, if you can meet the requirements for the referenced relaxations
and attach a label per 1.7.19, you might be able to get away with
"other means of security...."
The 4th edition of IEC 950 states the following:
1.2.7.3 RESTRICTED ACCESS LOCATION: A location for equipment where
both of the following dashed paragraphs apply:
- access can only be gained by SERVICE PERSONNEL or by USERS
who have been instructed about the reason for the restrictions
applied to the location and about any precautions that must be
taken; and
- access is through the use of a TOOL or lock and key, or other
means of security, and is controlled by the authority responsible
for the location.
NOTE: (Always, the most important statements seem to appear as
"Notes". T.Grant) -- The requirement for equipment intended for
installation in RESTRICTED ACCESS LOCATIONS are the same as for
OPERATOR ACCESS AREAS, except for relaxations given in 2.1.4.2
and 5.1 and an additional requirement in 1.7.19.
2.1.4.2 Protection in restricted access locations:
For equipment to be installed in a RESTRICTED ACCESS LOCATION, the
requirements for OPERATOR ACCESS AREAS apply except as permitted in
6.2.2 and in the following two dashed paragraphs:
- if a SECONDARY CIRCUIT at HAZARDOUS VOLTAGE is used to supply a
ringing signal generator that complies with 6.2.1.1.b, contact with
bare parts of the circuit is permitted with the test finger, figure 19
(page 239). However, such parts shall be so located or guarded that
unintentional contact is unlikely. In deciding whether or not
unintentional contact would be likely, account shall be taken of the
need to gain access past, or near to, the bare parts at HAZARDOUS
VOLTAGE.
NOTE - No requirement is specified regarding contact with TNV
circuits. See 6.2.2.
- bare parts that involve an energy hazard (see 2.1.5) shall be so
located or guarded that unintentional bridging by conductive materials
that might be present is unlikely.
6.2.2.1 ... for TNV-2 and TNV-3 circuits, exempts...
- bare conductive parts in SERVICE ACCESS AREAS.
5.1 Heating
.......
For equipment intended for installation in a RESTRICTED ACCESS
LOCATION, the temperature rise limits in table 16 parts 1 and 2 apply,
except that for external metal parts which are evidently designed as
heat sinks or which have a visible warning, a temperature rise of 65 K
is permitted.
1.7.19 Equipment for restricted access locations
For equipment intended only for installation in a RESTRICTED ACCESS
LOCATION, the installation instructions shall contain a statement to
this effect.
Tania Grant, Octel Communications Corporation
[email protected]
______________________________ Reply Separator _________________________________
Subject: Accessibility Discussion
Author: [email protected] at P_Internet_Mail
List-Post: [email protected]
Date: 9/4/97 9:43 AM
I would like to solicit your interpretation of Accessibility as stated in
EN60950 1.2.7.
I have had a power supply, which delivers -48 and -72 Vdc, manufactured by
a vendor. They have constructed the enclosure of the supply such that it
meets the Restricted Access Location requirements for opening, but not the
Operator Access Area requirements.
My equipment is telecommunications equipment, PBX, so only trained personal
will work on the equipment. Any calls to or Tech Support require proof of
training on that equipment before we will assist with repairing
troubleshooting. So in any case the operators would call for service. I
can't think of a case where a customer would want an employee to monkey
around with the phone system.
We sell in the UK and the engineer in the UK differs in interpretation. He
states "this means either a locked room or a further enclosure!"
Your interpretation and arguments for either side are appreciated.
Thank you
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Joe Dwyer
Manager of International Engineering
Inter-Tel, Inc.
7300 West Boston Street
Chandler, AZ 85226 U.S.A.
Tel: +1 602 961 9000 x1235
Fax: +1 602 961 6940
Email mailto: [email protected]
Home Page http://www.inter-tel.com
Employment http://www.nationjob.com/inter-tel
Inter-Tel is a single point of contact, full service solutions
integrator providing digital business communication platforms,
voice processing platforms, call processing and voice processing
software, CTI, network services and long distance calling services.
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