VT Guard Pro belongs to a new family of advanced protection devices which protect VTs against ferroresonant phenomena by proper and prompt damping action (Fig.
VT Guard Pro VT Guard Pro should be connected in open delta configuration of three single-phase VTs, as shown in Fig. 22. Nominal voltage level of the winding used for open-delta configuration should be 100/3 V or 110/3 V and it should be design at least for nominal current 4A.
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VT Guard Pro (Fig. 22, Fig.) Separate power supply is needed for diagnostic part. There are two recommended ways how to supply power to the diagnostic part (described in Fig. 4 and Fig.
3. Installation VT Guard Pro should be fitted in low-voltage compartment of the MV switchgear at the DIN – TS 35 rail Fig. 77 in vertical position at least 20 cm from other thermal sources. Connection should be done according to the Fig.
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Fig. 7 – DIN – TS 35 fixing X1:1 open delta configuration - live end 0 - 110 V AC Functional X1:2 open delta configuration - earthed end earthed X2:1 measurement/residual winding - earthed earthed Diagnostic X2:2 measurement/residual winding - live end 33 - 110 V AC X2:3 measurement/residual winding - live end 33 - 110 V AC Auxiliary...
4. Operating condition Appliance should be working indoor, with ambient temperature from -25 °C to +50 °C and humidity up to 90 %, not condensing water. No one should touch terminals with metallic objects, when appliance is under voltage. It is forbidden to place any objects close to or into ventilation gaps of the device.
7. Maintenance and service It is important to keep VT Guard Pro in cleanliness. Special attention should be paid to cleanliness of air-ventilation gaps. In case, of choked air-ventilation gaps the device should be disconnected from the circuit (both functional and diagnostic part), then the air-ventilation gaps can be cleaned by brush or compressed air.
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1VLM000651,Rev.3, en 2014.01.21 ABB s.r.o. EJF Organizational Unit Vídeňská 117 The data and ilustrations in this catalogue are not binding. 619 00 Brno, Czech Republic We reserve the right for making changes to the content Tel.: +420 547 152 602 in the course of technical development of the product.
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