A split-phase (240/120V) power system is a 3-wire, single-phase, mid-point neutral system, which consists of two 120V "voltage sources"; connected out-of-phase by 180 electrical degrees with a neutral connection between them. Note that the lesser known "Two-Phase" system is 90 electrical degrees out of phase and should not be confused with a split phase, (single phase system) or any "Three-Phase" source as these are 120 electrical degrees between coil groups.
The voltage between the two power conductors (L-L) is 240V, therefore the voltage between each live conductor and neutral (L-N) is 120V. Standard 120V lighting and small appliances are connected between a live conductor and the neutral.
Large appliances, such as resistive heating (space heaters), cooking equipment, water pumps, clothes dryers, and window air-conditioners are connected across the two hot conductors (L-L) and operate at 240V, requiring less current and smaller conductors than would be needed if the appliances were designed to operated at 120V. Since the current in each leg of a split-phase system is 180 degrees (out-of-phase), the neutral wire carries only the difference of current between the two lines, or zero current when the load on both legs are equally and or perfectly balanced(i.e. consuming equal amounts of power).
SET has developed smallest Type1 Surge Protective Device(SPD) for 120/240Vac systems.
- Withstand TOV 5s at 2 times rated operating voltage, disconnect if longer time.
- SCCR:200kA
- UL listed
- Smallest Type1 SPD
- In:10kA Imax:25kA/Mode
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