Dedicated, metered power that grows with your infrastructure
Power is the number that shapes every colocation deployment. Each cabinet at Cyber Wurx is fed by metered circuits sized to your hardware, and a little background on how those circuits work makes it easy to choose the right amount of power today and to know when it’s time to add more.
How Colocation Power Works
Three Things to Know
- Circuits set your capacity. Every circuit is defined by its breaker size (amps) and its voltage. Volts × amps gives the circuit’s rating in watts.
- Power is metered. Draw is measured on the circuit itself, so your usage reflects what your equipment actually pulls, not just what is installed in the rack.
- Plan around 80%. As standard data center and electrical-code practice, sustained load should stay at or below 80% of a circuit’s breaker rating. That headroom absorbs startup surges and keeps breakers from tripping.
Applying the 80% rule gives the usable power on each circuit size we offer:
| Circuit | Sustained limit (80%) | Usable power |
|---|---|---|
| 20A / 120V | 16A | About 2kW |
| 30A / 120V | 24A | About 3kW |
| 30A / 208V | 24A | About 5kW |
20A vs. 30A Circuits
20 Amp Circuits
A 20A circuit (about 16A of sustained load) is ideal for modest or predictable power needs. It typically supports:
- Standard 1U and 2U servers
- Small network appliances
- Low-to-medium density deployments
- Environments with lightweight or consistent power draw
A cost-effective entry point for customers with lighter hardware requirements.
30 Amp Circuits
A 30A circuit (about 24A of sustained load) offers 50% more usable power, supporting higher-density or variable-load hardware such as:
- Multi-server racks and blade chassis
- Database and virtualization hosts
- Large storage arrays
- Servers with high-wattage power supplies
The extra headroom reduces the risk of tripping limits during peak demand and leaves room for hardware growth.
120V vs. 208V Power
120V Circuits
120V power (often called 110V) is widely compatible and works well for traditional server and networking equipment. It is appropriate when:
- Your hardware ships with standard 120V power supplies
- You are deploying older or mixed-generation systems
- Your power demand does not require higher-voltage delivery
Straightforward, familiar, and available at every footprint from Shared Colo up to a Full Cabinet.
208V Circuits
208V power is the preferred choice for modern datacenter infrastructure, with better efficiency and more power per amp. Advantages include:
- More usable power at the same breaker size (about 5kW on 30A/208V versus about 3kW on 30A/120V)
- Improved efficiency for enterprise-grade power supplies
- A strong fit for virtualization hosts, storage arrays, and dense server racks
Available on a Full Cabinet as a 30A/208V circuit. Confirm your power supplies are rated for 208V; most enterprise-grade supplies are.
A+B Redundant Power
Two Matched Circuits for Maximum Uptime
An A+B configuration delivers two matched circuits to your cabinet: an A feed and a B feed. Each has its own breaker and its own power path, and both have identical amperage and voltage. Connect each power supply of a dual-PSU server to a different feed, with PSU 1 on A and PSU 2 on B. Normally the load is shared across both. If one feed trips, fails, or is taken down for maintenance, the other keeps the server running without interruption. It’s especially valuable for:
- Mission-critical applications
- Clusters and virtualization hosts
- High-availability deployments
- Any environment requiring maximum fault tolerance
It’s redundancy, not extra capacity
The B feed exists to back up the A feed. It is not additional power on top of it. Because either feed must be able to carry the entire load on its own, the combined draw across A and B has to stay within the usable limit of a single circuit. For a 30A/120V pair, that is about 3kW in total across both feeds, not 6kW. If each feed were loaded to its own limit, everything would work until one side dropped, and the surviving feed would then be asked to carry double its rating and trip, taking down the very equipment redundancy is meant to protect.
Systems with a single power supply can still use an A+B setup through an automatic transfer switch (ATS) installed in your cabinet, which gives the server one plug and switches between feeds. The equipment behind the switch counts against the same shared limit.
A+B redundancy is available on a Full Cabinet at each circuit size above. Shared Colo, 1/4 Cabinet, and 1/2 Cabinet run on a single feed.
Growing Into More Power
Power needs rarely stand still. A typical deployment moves up through these steps as it grows:
- Shared circuit. Shared Colo and 1/4 Cabinet share a metered circuit, a low-cost way to get started in the data center.
- Dedicated circuit. A 1/2 Cabinet gives you a circuit of your own, with a 30A upgrade for extra headroom.
- Full Cabinet. Choose 20A, 30A, or 208V power, with the option to add A+B redundancy.
- Dual feed. Add a second A+B pair for four circuits in total: A+A+B+B. Each pair is its own redundant set with its own usable limit, so your available power grows with the number of pairs while every load stays protected. Ask us about dual feed.
Signs It’s Time to Step Up
- Your sustained draw is sitting close to the 80% line on its circuit.
- You’re adding more servers, storage arrays, or virtualization hosts.
- You’d rather have a dedicated circuit than share one with other customers.
- Your workload can’t tolerate a single feed or a single breaker trip.
If you need help evaluating your power requirements or planning an upgrade, our team can recommend the right configuration for your rack now and as your infrastructure grows.