The weight and width on this page changed. Which figures are right?

The ones here. NorthStar's per-model sheet gives 30 kg, which is 66 lbs, and a case width of 108 mm, which is 4.25 inches. An earlier version of this listing published 72 lbs and 4.9 inches, both carried over from a different block in the range. Six pounds and two-thirds of an inch per block is enough to matter when four go into a tight bay or onto a shelf near its rating, so if either figure was used in a design, it is worth rechecking. Length at 15.6 inches and height at 10.4 inches were correct as published.

Will a string of four NSB92FT HT fit a 19-inch rack?

In most cases. Four blocks side by side measure 17.0 inches across, which fits inside the 17.7 inch opening of a standard 19-inch rack, and at 15.6 inches deep the block sits on a shallower shelf than the 22-inch HT blocks need. That leaves very little room between blocks and for the interconnects, so measure the shelf's clear width rather than the rack's nominal size. A string of four weighs about 264 lbs, and the specialist will check the shelf rating and the fit against the dimensions you send.

Can the NSB92FT HT go where a 100FT HT went?

Yes on the shelf, with a capacity step down to weigh. Both stand on the same 15.6 by 4.25 inch base with the same female M8 terminal, and the 92FT is about two inches shorter, so it drops into a 100FT bay with clearance. The trade is 8 Ah of reserve, which on a four-block string is roughly eight percent of the plant's runtime. Where the reserve target has margin, the 92FT is the lighter and usually lower-cost block; where it does not, the capacity is worth keeping. Send the plant load and reserve target and a specialist will say which way it falls.

HT RED or standard RED for my site?

Measure the cabinet rather than the outside air. Both are thin plate pure lead front-terminal blocks with a 15-year design life at 20°C and a -40°C to +65°C operating range. The HT build adds sustained operation at 40°C (104°F), and EnerSys warrants it for four years, one more than standard RED. A small sealed cabinet in sun runs well above ambient inside, which is where the HT build earns its place.