 Each furnace uses 1 kW of power; the voltage feed is 750 V (from the traction power supply), so the furnaces are mounted in electrically grounded outer casings for safety (2 furnaces in each casing).Each heating circuit has 5 furnaces connected in series and fed directly with 3000 V current from the traction circuits.As on the ER1, the ER2 car bodies are of a welded all-metal semi-monocoque load-bearing design (the entire car body bears all structural loads).