User Manual

SAFETY

Safety handbook page - 47 -

PNSPO

Live part:

A conductor or conductive part intended to be energised in normal use, including

a neutral conductor, but, by convention, not a PEN conductor.

Interlocking guard

Guard associated with an interlocking device, so that:

- the hazardous machine functions “covered” by the guard cannot operate

until the guard is closed;

- if the guard is opened while the hazardous machine functions are operating,

a stop instruction is given;

- when the guard is closed, the hazardous machine functions are “covered”

by the guard can operate, but the closure of the guard does not by itself

initiate their operation.

Note: In English ”stop signal” and “stop command” are synonyms for “stop instruction”.

Interlocking guard with guard locking

Guard associated with an interlocking device and a guard locking device so that:

- the hazardous machine functions “covered” by the guard cannot operate

until the is closed and locked;

- the guard remains closed and locked until the risk of injury from the

hazardous machine functions has passed;

- when the guard is closed and locked, the hazardous machine functions

“covered” by the guard can operate, but the closure and locking of the

guard do not by themselves initiate their operation.

Guard locking device:

Device intended to lock a guard in the closed position and linked to the control system

so that:

- the machine cannot operate until the guard is closed and locked;

the guard remains locked until the risk has passed

Direct mode actuation (positive mode actuation)

If a moving mechanical component inevitably moves another component along with it,

either by direct contact or via rigid elements, the second component is said to be

actuated in the positive mode (or positively) by the first one.

Direct opening operation of a contact element (positive opening)

The achievement of contact separation as the direct result of a specified movement

of the switch actuator through non-resilient members (e.g. not dependent upon

springs). [“Special requirements for control switches with positive opening operations”,

EN 60947-5-1: 1991, chapter 3,2.2].

Note: For fluid power, the equivalent concept may be called “positive mode

interruption”.

Stopping time

time for hazard elimination

The period between the point at which the interlocking device initiates the stop

command and the point at which the risk from hazardous machine functions

has passed.