Electrical wiring colour codes red which color colours ve dc rail 0v power electronics wikipedia info article here stack Electrical, heating and control products: meltric decontactors voltage 120vac wiring wire volt
120vac Color Code
120vac color code Color electrical control coding voltage volts heating meltric hz
Electrical, Heating and Control Products: Meltric deContactors Voltage
wiring - Red for +ve, black for 0v,which colour for -ve rail
120vac Color Code