Industries · Broadcast & Media
Orderly Power for Racks That Go On Air
Two hundred devices at 0.75mA of leakage each add up to 150mA — twenty-five times the 6mA that trips a GFCI. Studio, master-control and OB-truck racks need sequencing, surge tolerance and proof of power, which is precisely what our switched PDUs were engineered to provide.
Studio physics → firmware answer
Why broadcast racks trip breakers, and how sequencing stops it
The AVIOM power-sequencing procedures put hard numbers on what studio engineers already feel: residual currents accumulate, inrush arrives all at once, and amplifiers punish the wrong order. Each failure mode below has a firmware answer in an AmpRack switched PDU.
| Operating pain | Measured figure | AmpRack answer |
|---|---|---|
| Mass power-up trips the building's protection | 200 devices at 0.75mA residual each accumulate 150mA against a 6mA GFCI trip point (AVIOM) | Outlet-group sequencing brings the rack up in ordered banks with 0-999s delays, so leakage and inrush never land all at once |
| Inrush bullies small breakers | Industry practice rates 10A outlets to withstand surge events up to 40A (Server Technology) | Surge-protected variants plus hydraulic-magnetic breakers that hold through transformer inrush without nuisance trips |
| Loudspeakers punish the wrong power order | Amplifiers must power up last and power down first, per published sequencing procedure | Scripted on/off sequences per outlet group execute in one command, in the right order, every single time |
| On-air availability has a number on it | Tier 3 classifies 99.982% availability — about 1.6 hours down a year; Tier 4 is 99.995%, roughly 26 minutes | Dual-input ATS models plus per-outlet status readback keep the air chain verifiable at 2 a.m., not discoverable at sign-on |
| OB trucks and flypacks mix plug standards | One rack can carry NEMA and IEC 60309 feeds as it crosses borders | Input variants across NEMA L5/L6/L21 and IEC 60309 16/32/63A with C13/C19 outlet mixes — charted in the selection guides |
| Studio racks drift unattended over weekends | A single failing PSU can sit unnoticed until the Monday session exposes it | Metered inlets with threshold alerts by email or SNMP trap surface the drift while the rack is dark |
The on-air minute
Sequence, surge, verify
A broadcast rack's hardest moment is the power-up. Every transformer, power supply and amplifier draws inrush together, and the fault surfaces as a tripped feeder or — worse — a thumped monitor chain that ends a session. Sequenced groups fix the physics: amplifiers last on and first off, delays between banks, one command for the whole rack.
The verify half matters just as much. Per-outlet status and current readback prove every device truly energized before doors open — "sequence sent" and "sequence confirmed" are different answers, and only one belongs in a pre-air checklist.
Season result: an OB-truck integrator split its 18-way equipment racks into three sequenced outlet groups and ran a 40-event season without a single breaker trip.
Engineer-to-engineer
Three questions studio engineers ask first
Residual currents add up. At the 0.75mA ceiling per device, the 200th box in a facility pushes cumulative leakage to 150mA — twenty-five times a standard 6mA trip point. Sequencing limits how many devices energize together and spreads the residual sum across time instead of one instant.
Yes. Outlets are grouped and scripted: delays of 0-999 seconds per group, stored sequences for power-up and shutdown, and each step confirmed by measured current draw — so "command sent" is never confused with "actually on" during a pre-air check.
Broadcast facilities typically benchmark against Tier 3 — 99.982%, about 1.6 hours of downtime a year — or Tier 4 at 99.995%, roughly 26 minutes. A dual-feed ATS PDU with per-outlet switching is the rack-level expression of that target.
Power the next broadcast without the drama.
Rack layout, plug standards and sequencing order — an engineer replies with a unit proposal and FOB quote within 48 hours.
Sources: AVIOM power sequencing procedures (0.75mA residual current per device, 150mA accumulation over 200 devices vs 6mA GFCI trip; amplifier-last ordering); Server Technology product documentation (10A outlets rated to withstand 40A surge events); Uptime Institute Tier classification as commonly published (Tier 3: 99.982% / ≤1.6h per year; Tier 4: 99.995% / ≤26.3 minutes).
