Providing 64 amps (15kW) of fully redundant power per rack

Dual vs Diverse Whitepaper
Power provisioning

Custodian Data Centre not only provides clients with true diverse feed resilience with 100% uptime record, but our facility can also easily handle the high power requirements of High Performance Computing.

We are able to offer high levels of power per rack, via completely diverse power distribution paths. Each power feed arrives at the rack via a separate distribution board, uninterruptable power supply unit, changeover panel, generator and transformer.

Our site benefits from diverse grids that can switch in the event of a long term mains power outage. In the meantime, we carry enough fuel in our generators to run for 3 days, as well as having priority re-fuelling contracts in place.

With no need to purchase extra rack space in order to obtain more power, we can offer almost unlimited power availability with 64 amps being presented at each cabinet footprint as standard.

Our site benefits from
PUE – Power Usage Effectiveness


In addition to our power capabilities, Custodian Data Centre also operates at impressive annualised PUE levels, which are consistently lower than 1.2. We operate real-time monitoring of our PUE, which enables us to ensure that our data centre is always operating at its optimum functionality. Our worst case scenario for PUE operating levels is 1.46, when we run closed-loop on full chilling. At the other end of the scale, and during cooler months in particular, our PUE can be regularly as low as 1.11.

Diverse feeds

For a data centre to be considered to have diverse power feeds, its power provisioning must come from different power sources. From the rack all the way back to the generator. If a rack has dual feeds where both feeds eventually run back to the same UPS or generator it cannot be considered truly diverse. (For more in-depth information please take a look at our White Paper- Dual-Vs-Diverse.)

At Custodian, we only offer racks with truly diverse feeds from separate UPS systems, each of which has its own grid supply and its own fully independent Automatic Transfer Switches (ATS) system. We also have 3 separate 11kV transformers with three separate grid feeds to ensure we don’t run on our generators for a minute longer than we have to.

Custodian supply each rack with two separate 32 amp rated feeds which come via two individual distribution points and two separate UPS systems. Each UPS system operates independently and is only allowed to reach less than half load. It is capable of maintaining its respective zone entirely should another UPS fail and the load transfer.

We genuinely believe this is the only real way to achieve total availability and truly diverse power, as demonstrated by our 100% uptime record for power to all our racks since we launched.

Even our air handling equipment is backed up by UPS, ensuring there is no interruption to cooling while the generator starts.

Power monitoring

To ensure we can deliver on our 100% SLA, we employ detailed power system monitoring at every level of our power distribution system. This is then modelled, in real-time, to ensure that at any given time a failure and the subsequent ‘load shift and grow’ can be handled by the counterpart UPS, distribution and generator systems.

Our generators have enough fuel on-site to run for several days, rather than hours.

Fresh Air Cooling System: 90 hours (3.7 days)

Full Chilling System: 70 hours (2.9 days)

Priority re-fuelling contracts are in place to ensure rapid response to longer term generator requirements, although in the event of a long term outage we can transfer to one of our alternative grid feeds.

Our fortnightly generator test runs for four hours, which allows our engineers to fully test all parts of our system over a prolonged and managed period, giving us true (rather than synthesised) readings to analyse our operating systems.

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