Generator load bank testing

Load bank testing runs a site's standby generators against a real load, or one simulated by resistive load banks, long enough to prove that they take load, hold frequency and cool properly, and that the transfer switches operate. A generator run off-load every week proves almost nothing, because most failures seen in operation appear under load or during transfer. The whole chain has to be tested, from starter battery to fuel tank and on to the refueling contract itself. A claimed forty-eight hours of autonomy is worth something only if the supplier can deliver during a regional event that mobilizes every other site at the same time. Property insurers' survey grids commonly make this a condition of cover for critical sites, on a par with fire protection, and missing test records are a frequent basis for a reservation. A major outage can in fact come less from the generator than from the restoration maneuver, carried out by an operator who has never rehearsed it under real conditions: that is what British Airways said of its May 2017 incident.