Learning these electrical wire color codes before attempting any type of do-it-yourself (DIY) electrical system repair is critical. For wires that will be 120, 208 or 240 volts, the following wiring color standards are used. Just remember, all electrical wires could carry a current at some point, so treat every color wire with equal caution. These rules are applicable in the UK, EU and all other countries who follow the new IEC color codes instead of local and regional codes. Specific colors identify each wire’s function in a circuit. Is there a standard scheme for interstage coupling (such as phase inverter) transformer wire colors? Home > Radar Maintenance and Parts Manuals > > TRANSFORMER COLOR CODE (RMA STANDARD) COLOR CODING FOR CAPACITORS AND RESISTORS - continued - TM-11-5840-208-30-10015: BUTTON SILVER MICA CAPACITOR COLOR CODE: TM-11-5840-208-30 … The IEC DC wiring color codes are adapted from IEC AC wiring color codes. The following IEC DC wiring color codes are used for Two-Wire Grounded, Two-Wire ungrounded and Three Wire grounded DC power systems. It is important to note that with this type of wiring, there are multiple phases in place, each of which will get its own color wire to make it clear what it is for those working on it. "Start" and "finish" are arbitrary terms with respect to this configuration. Replacement transformers are not always identical, so if you get squeals or other odd sounds when hooking up a new output transformer, try reversing the output leads.