Search results
Results from the WOW.Com Content Network
Single-pole circuit breakers feed 120 V circuits from one of the 120 V buses within the panel, or two-pole circuit breakers feed 240-volt circuits from both buses. 120 V circuits are the most common, and used to power NEMA 1 and NEMA 5 outlets, and most residential and light commercial direct-wired lighting circuits.
Single-phase motors may have taps to allow their use on either 208-volt or 240-volt supply. A single-phase load may be powered directly from a three-phase distribution transformer in two ways: by connection between one phase and neutral or by connection between two phases. These two give different voltages from a given supply.
Lighting and general purpose receptacles are at 120 volts AC, with larger devices fed by three wire single-phase circuits at 240 volts. In commercial construction, three-phase circuits are often used. Common 3 phase configurations within a building are 208v/120 wye, 120/240 center tapped delta and 480v/277v wye. Lighting is usually fed by 277 V ...
Current practice is to give separate services for single-phase and three-phase loads, e.g., 120 V split-phase (lighting etc.) and 240 V to 600 V three-phase (for large motors). However, many jurisdictions forbid more than one class for a premises' service, and the choice may come down to 120/240 V split-phase, 208 V single-phase or three-phase ...
This allows one to choose single-phase AC power at either 110–120 volts between phase and neutral or 220–240 volts between phase and phase. Since these two modes do not need three phases there is also a dark yellow-orange four-pin connector available designed for a single-phase 110–120 or 220–240 volt load.
Delta – A 'delta' or 'phase to phase' transformer is used on a delta distribution circuit. A single-phase delta transformer has two bushings connected to two of the three primary wires, so the primary winding sees the phase-to-phase voltage; this avoids returning primary current through a neutral that must be solidly grounded to keep its ...
All these parameters vary among regions. The voltages are generally in the range 100–240 V (always expressed as root-mean-square voltage). The two commonly used frequencies are 50 Hz and 60 Hz. Single-phase or three-phase power is most commonly used today, although two-phase systems were used early in the 20th century. Foreign enclaves, such ...
Single-phase generator (also known as single-phase alternator) is an alternating current electrical generator that produces a single, continuously alternating voltage. Single-phase generators can be used to generate power in single-phase electric power systems.