If you are talking tankless electric, the only ones I am familiar with are the ones with resistance elements for heating. LRA (locked rotor amps) only applies to the starting of motor (compressor) loads. Heating elements would have only RLA (running load amps). Watts/voltage = current (amps) Tankless electric for homes typically range from 12 kW to 28 kW. At 240 volts this would yield 50 to 117 amps.