Earthing; Cable Door Interlock Mechanism - Eaton Power Xpert UX 12 User Manual

4.3

Earthing

This manual contains general instructions for fitting a
safety earth.
An installation may be fitted with specific interlocks (e.g.
a locking coil), which are intended to prevent the earthing
switch from switching on at the wrong time.
Only authorised and qualified personnel may fit
an earthing device.
NEVER approach an unearthed installation..
The following paragraphs discuss the way of applying an
earthing device:
 Earthing a cable using a built-in fixed earthing
switch. See par. 4.3.1
Earthing a busbar using a built-in fixed earthing

switch in the bus-sectionaliser panel. See par. 4.3.1
Earthing a busbar using a withdrawable earthing

unit. See par. 4.3.2
Earthing a cable using a withdrawable earthing unit .

See par. 4.3.2
The earthing switch can only be operated when:
 The unit is in the 'Insert/Removed' or 'Test' position;
The earthing switch is not locked with either a

locking coil or padlock. The maximum size of the
padlock hasp is 8 mm diameter.
The earthing switch can be padlocked in either the

"ON" or "OFF" position
Make the necessary provisions on both sides of the
cable before switching on the earthing switch.
4.3.1

Cable door interlock mechanism

The cable compartment door is mechanically interlocked
with the earth switch operating mechanism such that it is
only possible to open the compartment door when the
earth switch is in the On position (i.e. the cables earthed)
and it is only possible to open the earth switch when the
cable compartment door is closed.
Do not attempt to operate the earthing switch
when the cable door is open, the earth switch will
not operate and using force may damage the
interlock mechanism.
To open the door make sure the earthing switch is
switched On and cable is dead. This will release the
door interlock mechanism and the door can now be
opened.
WARNING
CAUTION
WARNING
NOTE
®
Power Xpert UX with W-VACi circuit breaker 6063308 G01 01 14 July 2011 www.eaton.com
Fig. 4-11
System operation
45