System Operation; Safe Switching; Switching On Safely; Switching Off Safely - Eaton Magnefix MD4 User Manual

4. SYSTEM OPERATION

This chapter contains the operating procedures for Eaton
Magnefix switchgear
C
AUTION
The switchgear should only be operated by
qualified and authorised personnel as prescribed
in this manual. Operations which are not
prescribed or those prescribed in unusual
circumstances, are only to be carried out with the
approval of the Eaton specialist in charge. This
specialist's instructions are to be followed to the
letter.

4.1 Safe switching

This section covers the safety aspects to be observed
when operating Magnefix switchgear.
It is quite safe to switch Magnefix switchgear on or off,
provided the following rules are observed.
W
ARNING
Disregarding these rules may cause accidents.
4.1.1

Switching on safely

For switch caps
Always operate a switch cap using the springing handle.
This is the only way to control switch-on arcs.
To limit arcing when switching on, it is necessary to switch
on a switch cap in two steps:

First: Place the cap against the stop on the cast
resin insulated member of the switch;

Next: Push the cap firmly down. The spring in
the springing handle will then ensure
rapid switching on.
If abnormal phenomena occur after switching on (such as
arcing or short-circuiting):

release the handle and keep a safe distance from the
installation;

do not switch off the cap immediately. Wait until the
protection devices have responded before taking any
further action.
For the protected panel
The vacuum circuit-breaker of the protected panel can only
be switched on if the adjacent switch caps have been
pulled out.
When switching-on for maintenance purposes, the vacuum
circuit-breaker must be locked, using the key-operated
switch. The key must be removed and retained by the
person performing the switching operations.
4.1.2

Switching off safely

For switch caps
W
ARNING
Never pull out a switch cap if an overcurrent or
short-circuiting condition exists.

Always operate a switch cap using the springing
handle. This is the only way to prevent arcing during
switching off.

Never pull out a switch cap if the overcurrent indicator
shows an overcurrent (the window is red), or if a short-
circuiting condition exists. Wait until the short-circuit is
removed.

If a triggered overcurrent indicator has no self-
resetting feature, try to reset it. If you do not succeed
in resetting the overcurrent indicator, there is likely to
be an overcurrent and the switch cap must not be
pulled out.

Immediately fit the cover on the cast resin insulated
member after switching off. If the cast resin insulated
member of the switch is live (cable side, busbar side
or both sides), affix a warning to the cover.
For the protected panel
The vacuum circuit-breaker of the protected panel has an
autonomous switch-off function. Push button (o) can be
used for switching off the system manually.
4.1.3

Safe earthing

Before earthing equipment can be fitted to a Magnefix
switchgear, it is necessary to check that the panel in
question is dead.
To reduce the risk of errors, the time between the check
and earthing should be kept to a minimum.
Magnefix MD4
991.184 G01 03 75