power transformer pt113a wire color code

When the transformer is installed in a home brew project this wire should be grounded. Tests should confirm that it is not shorted to any of the windings. This lead connects to an electrostatic shield between the primary and secondary. You may find one wire that seems to be odd man out. Secondary windings that have a high current rating, from 2 to 16 amps will be heavier gauge wire. You should confirm each winding by an ohmmeter test.

Red and yellow striped = High voltage secondary center tap. Yellow = 5 volt secondary, high current for 5Y3 or 5U4 filaments. Green and Yellow striped = 6.3 or 12.6 center tap. Green = 6.3 or 12.6 volt secondary, high current. In power transformers the lead colors are as follows. If you reside in that part of the world you had best find information that applies to the transformer's country of origin. Since I don't know I can't say what the lead colors on European power transformers might be. I know that the line voltage in Europe is 240 volts and I wouldn't be the least bit surprised to learn that transformer lead colors are different. North America uses 120 volt 60 Hz power and the transformer lead colors are almost universal. Using a pair of wire strippers will sometimes expose a bit of the original insulation color on the newly cut end. If the transformer is an open frame type there will be no end bells to protect a portion of the wire insulation. The tube may stay with the laminations or it may come out with the screw.

The long screws that go through the laminations are often insulated from them by a paper or plastic tube. The individual laminations are insulated from each other and must remain so if the transformer is to continue to function. Be careful not to lose any of the insulation which may come loose from the end bells. He suggests that if the leads are too faded by the dust of time that the transformer end bells may be removed to expose insulation that has not been exposed to the dust and other ravages of time.

This page is a result of a suggestion sent in by Gordon who asked for a page on the subject of transformer lead identification.

Power transformer pt113a wire color code