A motor lead for an electrical submersible well pump motor has three insulated conductors wrapped with a metal armor. A power connector has a housing with an upper opening into which the motor lead and a lower portion of the armor extend. The housing has an interior with a converging upper portion converging toward the upper opening. A slips member is located in the interior of the housing and has an upper opening into which the lower portion of the armor extends. The slips member has fingers that are wedged into the converging upper portion of the housing, which causes the fingers to deflect into the armor.