Rack Power Planning: 15A Circuits, Power Conditioners, UPS, and How Not to Trip Breakers

The fastest way to ruin a show is to trip the breaker your rack is plugged into. The math to avoid this is simple, the discipline to actually do it is what separates working rigs from racks that die at venues with quirky electrical.

The 15A circuit, in plain numbers

Most US venues hand you a standard wall outlet. That outlet is usually on a 15A circuit at 120V, which gives you a theoretical ceiling of 1800W. In practice you should treat the safe budget as 1440W (80% of capacity) for two reasons:

• Inrush current when you flip the rack on can briefly exceed steady-state draw by 2–3x.
• Other loads share the circuit — the venue might have hidden things on the same breaker (vending machines, stage washes, the green-room fridge).

IEM Rig’s power-budget bar uses 1800W as the hard cap and warns you in yellow as you approach 1440W — stay in green territory and you have headroom for everything else.

Adding up your rig’s power draw

Every component has two power numbers worth tracking:

• Typical draw — normal operating wattage with regular signal levels.
• Max draw — peak wattage with all phantom power on, all RF transmitting, all amplifiers driving.

Budget against max draw. The rig will probably never hit it all at once, but you don’t want to learn that the show you’re doing is the exception. Typical max-draw values for common IEM-rig gear:

• Power conditioner: 0–5W (just for its own electronics)
• Wireless IEM transmitter (1U full): 30–40W per unit
• Wireless IEM transmitter (half-rack): 15–20W per unit
• Audio interface (Apollo X16, Fireface UFX III): 60–80W
• Digital mixer (X32 Rack, M32R): 80–100W
• Stage box (S16, DX168): 30–50W
• Network switch (managed Gigabit): 20–40W
• Mac mini (M-series): 40–80W under load

A typical 4-piece-band IEM rig comes out to roughly 250–400W max — well inside the budget. Playback rigs with active speakers, multiple interfaces, and a couple of computers can push 800–1200W and start to crowd the budget.

Power conditioner vs UPS — they’re not the same

A common mistake is buying a Furman PL-Plus and assuming it keeps the rack alive through power dropouts. It doesn’t — a power conditioner is essentially a fancy power strip with filtering and surge protection. If the venue’s power dies, so does your rack.

Power conditioner

• Filters incoming AC noise.
• Suppresses surges and spikes.
• Provides switched outlets for clean rig on/off.
• Sometimes includes pull-out lights and voltmeters.
• Doesn’t store any power. Power loss = rack off.

UPS (uninterruptible power supply)

• Battery-backed — survives momentary power dropouts.
• Typical capacity: 5–20 minutes of runtime depending on load.
• Heavier and more expensive than a conditioner. Adds 15–30 lbs to the rack.
• Right for: playback rigs running show-critical computers, FOH consoles you can’t risk losing during a song, broadcast feeds.

Practical setup tips

1. Sequence your power-on — turn devices on in the order signal flows. Source first (computer, console), then processing, then transmitters. This avoids RF mute relays clicking through audio that’s suddenly there.
2. Don’t daisy-chain conditioners — plug each conditioner directly into the wall (or UPS). Stacking conditioners doesn’t double protection, just doubles failure modes.
3. Label your outlets — if your conditioner has switched banks, label which devices are on which switch so your tech can reset just the offending bank without killing the whole rig.
4. Carry a 25 ft extension cord — the wall outlet is never where you want it, and a long quality 12-gauge extension is cheap insurance.
5. Bring a clamp meter — measure actual draw at the wall on first power-up. Tells you immediately if your spec sheet math was off.

Planning power in IEM Rig

When you build a rig in IEM Rig, the Summary panel surfaces both your typical and max wattage live as you place components. The power-budget bar turns yellow at 80% and red at 100% of the 1800W ceiling — if you ever see red, the rig will likely trip a stock 15A circuit at peak.

For multi-circuit setups, plan each rack on its own outlet and keep their loads roughly balanced — the Bill of Materials export breaks out per-rack power so you can plan distro panels.