The Lug Says 275 in-lb and the Van Has a ft-lb Wrench

Correct answer: D) The conversion comes to about 23 ft-lb, which sits near the bottom of this wrench’s range where it is least accurate; this termination needs an in-lb wrench

The conversion is the easy half and it is not where the problem is. There are twelve inch-pounds in a foot-pound, so 275 in-lb is about 23 ft-lb, and anyone can do that on the way up the ladder. The difficulty is that 23 sits at the very bottom of a wrench that runs to 150, and a click wrench is at its least accurate down there. Manufacturers generally state accuracy over the upper part of the range for exactly this reason. Setting a number the tool cannot reliably deliver produces a termination you have documented as torqued and have not actually torqued.

Both directions of getting it wrong have a cost, which is why this is worth a second trip to the van. Under-tightening leaves a joint with more contact resistance than it should have, and a joint with resistance turns current into heat, climbs as it degrades, and is invisible on the monitoring portal until a thermal camera finds it. Over-tightening damages conductor strands, can crack a lug, and with aluminium conductors starts a slow cold flow that loosens the joint over the following months. The specification exists because there is a band between those two, and it is not wide.

The O&M point: the crew who built this site set up once, for one kind of equipment, with the tools that job called for. You work across a portfolio, and a single visit can involve terminations from three manufacturers whose documents use inch-pounds, foot-pounds and newton-metres in whatever combination they happened to choose. The unit is part of the specification and not a detail of how it was written down, and the van needs to carry the range of tools that follows from that rather than the one wrench that covers the biggest numbers.

Why the other options are wrong

A) Convert to about 23 ft-lb and use the wrench on the van, since the conversion is exact and the result is therefore correct

The arithmetic is right and it stops one step short. An exact conversion tells you what number to set; it says nothing about whether the instrument in your hand can deliver that number. This is the answer that produces a torque mark, a tick in the service report and a joint whose tightness nobody actually knows, which is worse than an untouched joint because it now looks verified.

B) Tighten it by feel — 275 in-lb is a small value, and a quarter turn past snug is close enough

Feel is not a unit. The whole reason a value is printed on a label inside the enclosure is that the band between too loose and too tight is narrower than a person can judge by hand, and "past snug" means different things through different lug designs, different conductor materials and different wrist strength. It is also unverifiable afterwards, which matters when somebody is investigating a failure at this terminal in two years.

C) Set the wrench to its lowest setting of 10 ft-lb, since staying under the specification is the safe direction to err in

Under-torque is not the safe direction, it is simply the other failure. A loose termination carries the same current through less contact area, so it runs hot, and heat degrades the joint further, which makes it hotter. Erring low has the additional problem of being deliberate: an accidental under-torque is a mistake, and choosing 10 ft-lb against a 23 ft-lb specification is a decision recorded in your own service notes.

References

• NABCEP OMAT JTA v.2026.5 — Domain 3, Task 3.A: "Manufacturer manuals and specifications (e.g., termination torque specifications, NEMA ratings, sunlight exposure)". The torque value is a manufacturer specification for that termination, which is what the JTA names; it is not a figure from a code or standard.
• No standard is cited for torque wrench accuracy. That a click wrench is least accurate at the bottom of its range is a property of the instrument, stated by its own manufacturer, and the conversion of inch-pounds to foot-pounds is arithmetic.