This is the actual measured DC current the rectifier plant is delivering to the load right now, per the description and its stated 0000-5000 amp valid range. Because the valid range extends up to 5000 amps, this is a central-office- or large-cell-site-class plant, and a load current that climbs steadily over weeks rather than staying flat usually means new equipment was added to the DC plant without anyone re-checking rectifier capacity headroom. A reading of 1800 amps against rectifiers sized for 3000A of capacity leaves comfortable headroom, whereas 2950 amps would leave almost none.