A despicable act, worthy only of contempt - that was how a judge described a man's theft of emergency generators soon after Christchurch's February 22 earthquake.



Judge Stephen Erber said it was an attack on a community at a time when it was vulnerable, as he sent Owen Anthony Jackson to jail for more than three years.



Jackson, 23, and an alleged co-offender, stole three generators they found on the street on the day after the February 22 earthquake, one for Jackson's own use, and two to sell.



Defence counsel Joseph Griffiths said the generators were not connected. They were to serve as back up power supplies if the batteries in the telecommunications building failed.



He said Jackson told police he was stupid and he was sorry.



He had not taken his Ritalin medication on the day of the earthquake, or the day when he stole the generators but Judge Stephen Erber said Jackson's attention deficit hyperactivity disorder could not be used as a crutch for bad criminal behaviour.



He said the generators were worth $6000 and belonged to TelstraClear.



Judge Erber said the earthquake caused major damage and loss of many lives, and even if the generators were not being used at the time, Jackson must have realised that they were connected with earthquake relief in some way.



Jackson and the co-offender went to three separate locations to steal the generators, then drove home and tried to sell two of them, he said.



Judge Erber said Jackson's record indicated an inclination to dishonest activity.



They were cynical thefts which recognised the value of the generators at a time of emergency, and there was general disbelief that anyone would do this in those difficult times, he said.



He sentenced Jackson to prison for three years and three months and disqualified him from driving for 12 months.