I suspected that might be the case. The power being switched off is the only time the EMUs I'm familiar with would be powered down.I’d say it’s normal practice to leave all EMUs powered up. The only time to trip them down is if the juice is going to be off for any reason. Even when powered down correctly trains are pretty temperamental when being powered back up again, especially if they’ve been left in the open and this subject to weather (especially cold / wet / snow), drained batteries is the most obvious problem. It isn’t just older EMUs that have a monopoly on being troublesome either!