Is protection needed for the secondary side of the 10kV metering PT?
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During the first power-up of the busbar in the new 10kV substation, the PT started to smoke and was damaged after five minutes; upon further inspection, it was found that the secondary wires inside the PT carriage had been worn and damaged during installation, resulting in grounding and thus a short circuit that caused the PT to be destroyed. The manufacturer’s designers said that the power company requires that no fuses be installed on the secondary side of the metering PT; this requirement wasn’t found in any standards either, so let’s discuss it together.
It is basic common sense that a fuse should be added for this. It’s impossible not to add it.
The lack of fuses on the secondary side of the metering PT is due to the power supply department’s concern that the metering meter will not be able to function properly in the event of a fuse blowout. Generally, the power supply department provides this cabinet itself; the PT secondary side is connected directly to the energy meter, without using terminal blocks, thereby reducing the number of wiring connections and minimizing the risk of secondary side failures. Can you place orders for this by yourselves? Will the power supply company agree?