STATEMENT
Customer: MEA
Description of goods : Disconnectors CBD 123-2000 with quick whip breaking device
Coelme Job order : B01562
Subject of the document : To declare the formal position of COELME-Egic about the
operation of disconnectors at site recorded by video of
10/01/13
We analysed the video receivedfrom MEA on 10/01/2013, showing the opening operation
of an energized disconnector (configuration dwg ref. B01562ECDC01 with quick whip
system installed).
The behaviour of thisapparatus was then compared to that recorded during the switching
tests performed at CESI, which were performed to fully cover the range of magnetizing
current ratings to be switched specified by MEA (type test report CESI B1010922), i.e. 7A at
the rated voltage to ground.
We performed the test with a magnetizing current rated 10A at the required voltage.
First of all, it has to be noted that tested disconnector was similar to those delivered
because:
Type and model are the same
Main dimensions are the same, except for a small difference on insulator height,
which is negligible for the test result
The speed of operation is the same(open cycle duration is about 8s)
Consequently, a similar behaviour of disconnectors installed at sitewas expected but,
surprisingly, an arcing time was recorded atsite higher than the one measured during the
type test.
In our opinion, the different arcing time is mainly due to the following reasons:
The current and voltage values of the magnetizing current at siteare higher than
those declared by MEA and tested at CESI
The configuration ofMEA installation (on concrete pole and phase over phase) might
be worse in term of distance to earth of each pole and, therefore,it might cause a
different behaviour of the arc.
Today, a study is under development in Coelme and a new investigation will be carried out
to understand as much as possible how MEA’s configuration (phase-over-phase with a
concrete pole behind) and other parameters, such as voltage and value of magnetizing
current, distance between the pole and the concrete pole, speed of operation and quick
whip system can influence the performance of the apparatus.
At the end of the internal investigation and on the occasion of the next order from MEA, new
suitable switching test will be carried out at an independent laboratory, before the delivery.
We would like to point out since now that, inour opinion, considering the high value of
current to be switched, the need of quick whips remains even with mechanisms able to
operate the disconnector in less than 5 seconds, as required by the new specification of
MEA .
Santa Maria di Sala-Italy July 05, 2013
STATEMENTCustomer: MEA Description of goods : Disconnectors CBD 123-2000 with quick whip breaking device Coelme Job order : B01562 Subject of the document : To declare the formal position of COELME-Egic about the operation of disconnectors at site recorded by video of 10/01/13We analysed the video receivedfrom MEA on 10/01/2013, showing the opening operation of an energized disconnector (configuration dwg ref. B01562ECDC01 with quick whip system installed). The behaviour of thisapparatus was then compared to that recorded during the switching tests performed at CESI, which were performed to fully cover the range of magnetizing current ratings to be switched specified by MEA (type test report CESI B1010922), i.e. 7A at the rated voltage to ground. We performed the test with a magnetizing current rated 10A at the required voltage. First of all, it has to be noted that tested disconnector was similar to those delivered because: Type and model are the same Main dimensions are the same, except for a small difference on insulator height, which is negligible for the test result The speed of operation is the same(open cycle duration is about 8s) Consequently, a similar behaviour of disconnectors installed at sitewas expected but, surprisingly, an arcing time was recorded atsite higher than the one measured during the type test.In our opinion, the different arcing time is mainly due to the following reasons: The current and voltage values of the magnetizing current at siteare higher than those declared by MEA and tested at CESI The configuration ofMEA installation (on concrete pole and phase over phase) might be worse in term of distance to earth of each pole and, therefore,it might cause a different behaviour of the arc. Today, a study is under development in Coelme and a new investigation will be carried out to understand as much as possible how MEA’s configuration (phase-over-phase with a concrete pole behind) and other parameters, such as voltage and value of magnetizing current, distance between the pole and the concrete pole, speed of operation and quick whip system can influence the performance of the apparatus. At the end of the internal investigation and on the occasion of the next order from MEA, new suitable switching test will be carried out at an independent laboratory, before the delivery. We would like to point out since now that, inour opinion, considering the high value of current to be switched, the need of quick whips remains even with mechanisms able to operate the disconnector in less than 5 seconds, as required by the new specification of MEA . Santa Maria di Sala-Italy July 05, 2013
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