Video: Shark 100 – Technical guide

Video transcript

How the Shark 100 is mounted, how its current and voltage inputs are wired in star and in delta, how it is powered and connected, and how it is programmed. This is work on live circuits, for qualified staff only. The voltage leads and the supply are protected by fuses, the CT circuits go through a shorting block, and a switch next to the meter isolates it. And never open a CT secondary while current is flowing. The meter fits either of the two panel standards: a round ANSI 4 inch cut-out with 4 fixing holes,

or a 92 millimetre square DIN cut-out, with its brackets. The gasket keeps the front water resistant. The transducer version clips onto a DIN rail. Current can be wired in two ways. The CT lead can pass straight through the meter, with no termination at all, so the meter adds no burden and can never open the CT circuit. Or it can be terminated on the pass-through bars with a screw. The inputs are colour coded, and they withstand 500 amps for one second.

The voltage input is universal: up to 416 volts phase to neutral and 721 between phases can be connected directly. Above that, P Ts are used, and their ratio is programmed. Four hookups are supported: star with 3 or two and a half elements, delta with two elements, and four-wire delta. In a four-wire low-voltage star, the Shark 100 connects directly, with 3 C Ts. The CT common is earthed first, then each CT goes through the shorting block, polarity mark to HI.

The neutral goes to V ref, and each phase reaches V a, V b and V c through its fuse. In a three-wire delta, two elements are enough: C Ts on phases A and C only. After the earth and the two C Ts, the 3 phases go directly, through their fuses, to V a, V b and V c, and V ref is bridged to V b on the meter. With higher voltages, P Ts go in between. The meter needs its own supply: D two, universal, for 90 to 265 volts AC or a 100 to 370 volts DC, or D, for 18 to 60 volts DC.

Earth first, then neutral or negative, and finally line or positive, through a fuse and with a switch nearby. With the RS-485 option, the meters are chained one after another, never in a star, on shielded twisted pair. The shield is earthed at one point only; then plus to plus, minus to minus and shield to shield, with termination only at the two ends of a long line. Programming is done from the front, with MENU, ENTER and the arrows,

or from a PC, through the infrared port or the communication option. Set the CT and PT ratios and the hookup, then the address and protocol. And if more functions are needed later, the upgrade key is activated in the field. Before leaving the site, check the result on the meter itself. The phasor diagram on the display shows at once whether the phase sequence and the CT polarity are right. And the watt-hour test pulse on the front lets you verify the accuracy against a reference.

Power network analysers, from Amperis.