Single-phase
One hot wire (120V) or two hots (240V) plus neutral. Power pulses — it hits zero 120 times per second. Fine for homes and light commercial: lighting, receptacles, small HVAC. Breakers are 1- or 2-pole; panels are load centers.
EXPLAINER
Single-Phase vs. Three-Phase, Explained.
One wave or three — what the difference is, the voltages you will see, and what phase means for every piece of electrical equipment.
EXPLAINER
One wave or three — why industry runs on three.
Homes run on single-phase power: one alternating current wave. Industry runs on three-phase: three waves, each offset by a third of a cycle, combining into power that never drops to zero. That constant power is why three-phase motors run smoother, smaller, and more efficiently — and why every factory, data center, and commercial building you will ever buy equipment from is wired for it.
Buying or selling 3-phase gear?
Three-phase breakers, panels, and transformers are the commercial market. See what they are worth →
THE DIFFERENCE
Single-phase vs. three-phase
Three-phase
Three hot wires, each 120° out of phase. Power delivery never hits zero — it is constant, which means motors run without vibration, deliver more power per pound of copper, and start on their own without capacitors. The standard for anything industrial.
The voltages you will see
208Y/120V: commercial buildings (three-phase 208 + single-phase 120 for receptacles). 480Y/277V: industrial and large commercial (480 three-phase for equipment, 277 for lighting). 240V delta: older industrial, including the high-leg delta with its infamous orange wire. Nameplate voltage tells you which world a piece of equipment belongs to.
WHY IT MATTERS
What this means for equipment
Breakers
Three-phase breakers are 3-pole — visibly wider, with three handles tied together. They serve the commercial market and hold value better than residential single-poles. A 3-pole 480V breaker is a different asset class from a single-pole 120V.
Panels and transformers
Three-phase panelboards (208Y/120 or 480Y/277) and three-phase transformers are the equipment that trades between businesses. Single-phase gear mostly serves the residential replacement market.
Can you convert?
Running three-phase equipment on single-phase requires a phase converter or VFD — common for a home shop running one mill, impractical at scale. Running single-phase loads on three-phase is trivial (use one phase + neutral). Equipment voltage and phase must match the building: check both on every nameplate.
THE ODD ONE
High-leg delta: the orange wire
Older industrial buildings sometimes have a high-leg delta (wild-leg) service: 240V three-phase delta with one transformer center-tapped to make 120V. The catch: the “high leg” (always the B phase, marked with orange wire by code) sits at 208V to neutral — connect 120V loads to it and they fry instantly. If you are buying equipment from an older plant and see orange wire in the panels, you are looking at high-leg delta: verify every voltage before energizing anything, and note it in the listing — the next owner needs to know. Most new services are 208Y/120 or 480Y/277 wye instead, which have no high leg.
QUESTIONS
Phase questions, answered.
What is the difference between single-phase and three-phase?
Single-phase is one AC wave (residential); three-phase is three waves offset 120 degrees apart, delivering constant power. Three-phase motors run smoother, smaller, and more efficiently — it is the industrial standard.
How do I know if I have three-phase power?
Check your panel: three-phase panels have 3-pole breakers and nameplates reading 208Y/120V or 480Y/277V. Or call your utility — most homes are single-phase; most commercial buildings are three-phase.
Can I run three-phase equipment at home?
With a rotary phase converter or VFD for a single machine, yes — common in home machine shops. Whole-shop three-phase at a residence usually is not available from the utility.
Is three-phase more dangerous?
The voltages are higher (480V vs 240V), so faults release more energy — arc flash is a serious industrial hazard. But properly installed three-phase is no less safe; it is simply a bigger system demanding proper respect and qualified electricians.
Why do factories use 480V?
Higher voltage means lower current for the same power, which means smaller wire, less energy lost as heat, and cheaper distribution across a large facility.
HOW IT WORKS
Three steps to an offer.
01Send photos
Photograph the equipment, nameplates, and quantities in place, then send them through the contact form.
02Material review
We review what the equipment is, its condition and quantity, and how it grades for resale versus recovery.
03Receive an offer
For qualifying material, we discuss a direct purchase offer and the next steps.