721-0series -0 subseries -2100 subseries -3000 subseries -3100 subseries -4000 subseries -5000 subseries Type index
	JR Hokkaido developed 721 series for the commuter train in the suburbs of Sapporo in 1988. 721 series are equipped with 3 doors at each car and all seats are switchable cross seating. The air conditioners are fitted among trains for local services in Hokkaido for the first time. 721 series adopt bogies given some improvements to DT50 used for 211 series and so on. Brake devices are not disk brake but tread brake against heavy snow damage. 2 out of the 3 cars are motored, giving a maximum services speed of 120km/h, with 150kW dc traction motors controlled by thyristor phase traction system, which are based on the traction systems of 713 series. Their traction system futures the added field weakening control. Traction motors are ventilated with the air from which airborne snow is removed from intake air like 711 series and motored cars of 721 series are equipped with equipment removing airborne snow. 721 series don't adopt regenerative brake like 713 series but rheostatic brake. So brake registers are fitted on the roof of the end motored cars. Due to the popularity of the "Airport" rapid services, some formations were increased to 6 cars from 1992 with the addition of extra type Moha720 intermediate motored vehicles and Saha721 intermediate trailer vehicles. Some kuha721 and saha721 vehicles used on airport rapid services were refurbished with adjustable reclining seating for reservation services in 2000. These refurbished kuha721 were downgraded to the switchable cross-seating again 2003. Now 721-0 series are used on the rural services in the suburbs of Sapporo.
	Technical Data Items Data Supply Voltage 20000VAC, 50Hz Service speed, etc. Acceleration: 2.4km/h/s Deceleration: 4.1km/h/s Service speed: 120km/h Length 20800mm Width 2954mm Height 3670mm Bogie N-DT721 (motored) N-TR721 (trailer) Collector N-PS721 Traction motor N-MT721 (150kW) Gear ratio 4.82 Transformer N-TM721 Rectifier N-RS721 Traction system Thyristor phase control : N-CS721 Air conditioner N-AU721 (20000kcal/h×1) Designed by JR Hokkaido