Definition
Under ISO 8528, a generator set carries different power ratings depending on how it will be used, and choosing the wrong one is a common and costly mistake when sizing power for continuous mining. The two ratings a miner most needs to understand are prime power and standby power.
Prime power (PRP)
Prime Rated Power is the maximum output a genset can supply to a variable load for an unlimited number of hours per year, provided maintenance intervals are honoured. The catch is the load factor: the average load over any 24-hour period must not exceed 70% of the prime rating. A short, defined overload above prime is permitted for limited periods. Prime is the relevant rating for a genset that will run hashing equipment around the clock.
Standby power (ESP)
Emergency Standby Power is the maximum output available during a utility outage, intended for emergency use only, with anticipated annual operation of no more than about 200 hours and the same 70% 24-hour average load cap. An ESP rating is always higher than the same engine's prime rating because the manufacturer assumes the unit runs rarely. Sizing a continuous mining load against a standby number will overload and prematurely wear the engine.
Why it matters for miners
Because hashing is a near-constant 24/7 load, an on-site mining genset must be specified at its prime, or even continuous (COP), rating, never standby. Read the nameplate carefully and confirm the prime kW figure covers your full draw with headroom. Combine this with the unit's heat rate and turndown ratio to plan a reliable, efficient genset deployment.
In Simple Terms
Under ISO 8528, a generator set carries different power ratings depending on how it will be used, and choosing the wrong one is a common…