Dear Friends,
I've received some contradicting information in relation to the need
for interlocks, and would like to bring it up to the group for
discussion. We have an instrument that has a removable side panel. A
tool is required to remove the panel and there is hazardous voltages
behind the panel. The user is instructed to remove the panel for
installing options, and maintenance.
Opinion 1 - Access is restricted by a tool, so no interlock is
required. EN61010-1 sec 6.1.1 states:
The following Hazardous live parts are permitted to be accessible to
the operator during normal use:
- parts intended to be replaced by the operator (e.g. batteries) and
which may be Hazardous live during the replacement or other operator
action, but only if they are accessible only by means of a tool and
have a warning marking..
Opinion 2 - When an operator is instructed to remove the panel, an
interlock is required. An agency told me that once an operator is
instructed to remove a panel, it is treated as if no tool was required
to remove it.
Also, if anyone has information on high integrity components, such as
interlock switches and relays, I would appreciate some information.
Thank you for your thoughts.
Ray
[email protected]
