COMEM RDR-MK II Manual De Instrucciones página 6

RDR-MK II shutter valve is used in order to avoid the oil comes out from conservator fol-
lowing to an important oil loss which may happen due to a serious accident (for instance
a break in the bushing porcelain caused by an atmospheric discharge, a break in the tran-
sformer tank caused by an accidental hit, etc.).
In each particular condition described above, the shutter valve has to work by closing the
pipe which goes from the conservator to the transformer's tank. In this way the oil cannot
freely flow any longer and consequently the transformer has to be disabled immediately.
It is very important to verify that the shutter valve is open before to start the transformer.
In fact it may happens that the transformer remains disabled for long time or that during
the transport the disk valve closes itself due to the oil missing or the anomalous flow.
We advise you to follow the instructions below carefully.
In case the shutter valve operates due to an oil leakage from hot transformer, the shutter
valve blocks the oil flow.
If the transformer is started without having reset the shutter valve
oil became cool, a depression inside the tank was created with consequent formation of
oil steams below the cover.
The electrical strength of such a mixture is low and in case the transformer is energised,
it can generate a destructive discharge. Such a discharge may happen when the transfor-
mer is operating.
So that in case the shutter valve operates, the transformer must be disabled
and the user must investigate the causes of the operating. He has to solve
them before to reset the shutter valve and start the transformer again.
If the customer need the shutter valve on the transformer, he also needs that a Buchholz
relay is installed. Both of them have to be supplied with electric signalling contacts of
alarm and release.
Furthermore the oil level has to be provided with a contact of min., at least.
In case the customer needs the shutter valve without contact or without relay, it is duty
of the maintenance engineer to make recurring visual verifications of right working.
The construction electrician has to foresee the electric connection of the shutter valve to
the release coil of HV switch, so as to turn off the voltage to the transformer in case the
shutter valve operates.
Furthermore there is need to connect the alarm switch of the relay to the coil as well in
case the shutter valve switches are not connected.
COMEM
COMEM S.p.A.
Features
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