Lionel V transformer

Loading thread data ...
Before plugging in an old transformer, give it a thorough mechanical inspection. Look at the diagram at:
formatting link
Make sure the cord is not frayed or cracked. Make sure there is no burned insulation smell. Open the case by removing the knobs, removing the top metal label plate, removing the large screws under the label plate, and removing the top part of the Bakelite case. Inspect for any signs of burning or scorching on the transformer. Inspect the four moving contact arms and make sure the carbon rollers that rub on the transformer winding are intact and rotate freely. Trace the wires per the wiring diagram and make sure none of the wires are disconnected. If all is well, reassemble the transformer.
Plug it in. Observe that the green pilot light comes on. Use a voltmeter to measure the output at A to U, B to U, C to U and D to U as you vary each control knob. Observe that the voltage varies smoothly without interruptions over the range specified on the label plate. If all is OK, turn a control to maximum, and use a screw driver to make a short circuit from that control's output post to the U post; observe that the circuit breaker opens within a couple seconds and the red "short" light comes on. DO NOT apply the short for more than a few seconds if the breaker does not operate.
If it passes all of the above the transformer should be OK, but use it under adult supervision for the first few hours to make sure that it does not overheat, emit smoke, or unusual odors. Geezer
Reply to

Site Timeline

PolyTech Forum website is not affiliated with any of the manufacturers or service providers discussed here. All logos and trade names are the property of their respective owners.