Recommended sequence of operations
28
General instructions
cgmcosmos
system
Medium voltage switchgear and control gear, fully insulated in SF
6
gas up to 24 kV with external cable test device
IG-257-EN version 01; 03/02/2016
The purpose of the test points for the three phases and
earth is to make it easier to check the phase balance
[9]
between cubicles.
Ormazabal
's specific phase comparator
ekor.
spc
can be used to do this.
With the
ekor.
vpis
, if the indicators do not
light up, use other means to check that there
is no voltage.
5.3 Checking phase balance
Ormazabal's
ekor.
spc
[10]
phase comparator should be
used to check that the medium voltage cables are correctly
connected to the transformer substation feeder cubicles.
Fig. 5.3
ekor.
spc
unit
Firstly, connect the red cables of the
ekor.
spc
unit to the corresponding phase test points on
the voltage indicator units
[11]
, and the black cable to the
earth test point. This operation must be repeated for all the
phases: L1, L2 and L3
Fig. 5.4
Detail of connections
ekor.
spc
Comparison of balanced phases
Fig. 5.5
There is NO indication on the comparator
Comparison of unbalanced phases
Fig. 5.6
YES there is indication on the comparator
[9]
[10]
[11]
[9] See section 5.2.
Checking voltage presence and phase balance.
.
[10] Optionally, other comparison devices which comply with the IEC
62271-206 standard may be used.
[11] See Section 5.1.1
. Checking voltage presence
of this General
Instructions document.
Содержание cgmcosmos-2lv
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