Class 2 Control Transformers Triad Magnetics Control Transformers are UL1585 Class 2/3 approved. The Class 2 transformers are designed with tamper resistant shrouds for safety and steel brackets welded to the bottom of the transformer for ease of mounting and are available in 40VA and 50VA ratings. Applications include relays, solenoids, small motors, speed changers, pumps, heating elements, control valves for fluid and gas, fans and blowers, electronic tubes, automatic assembly equipment, recording devices, elevators, door openers and low voltage lamps.