Power Planning: Designing Electricity Backwards from the Device List
The Four-Step Method
- Load list: voltage, power (sustained/peak), current and plug type per device — get electrical spec sheets from vendors and register each unit.
- Circuit allocation: one circuit per high-draw device; circuit capacity = peak × 1.25 safety factor; lighting and office on separate circuits.
- Margin: reserve 20-30% free breaker slots — the second device always arrives earlier than planned.
- Coordination points: pipe-and-wire inspection before boards close; power-on testing before devices arrive.
Typical Load Profiles
| Device class | Electrical character |
|---|---|
| High-power lasers/hair-removal platforms | Single- or three-phase, kilowatt-class sustained, high peak current |
| IPL/RF units | Pulsed loads, sensitive to circuit stability |
| Chillers | Sustained duty + pump start currents |
| Imaging/analysis | Low power but EMC-sensitive (EMC) |
The Frequent Questions List
- Three-phase needed? — Confirm against the largest device; the renovation window is the only cheap time.
- Unstable grid areas: regulators for sensitive equipment (see electrical safety).
- Generator/UPS: size from “how does the client on the bed finish safely” backwards.
FAQ
Who does the planning?
A three-way loop: fit-out electrician draws, device vendors confirm, the clinic reviews — trusting any single party leaves holes.
Adding a device later — rewire?
Depends on margin: free breaker slots and spare conductor capacity mean just adding a circuit; otherwise the panel upgrades — which is exactly why you planned margin.