Data centre procurement · 3 min read
Electrical procurement for data centres: what to settle first
UD Fomra Group ·
Data centre electrical packages are driven by one early decision: how much redundancy the facility needs. That choice sets how many transformers and feeders there are, how cables are routed and rated, and which items go on the critical path. Settle it before asking for prices.
Redundancy sets the quantities
Designs are usually described as N, N+1 or 2N. In a 2N design every rack is fed by two independent paths, A and B, each able to carry the full load, so transformers, LV boards and cable runs are effectively doubled. An N+1 design adds one spare unit to a shared system instead.
The design team's single-line diagram and the redundancy level should travel with the enquiry, because they change both the bill of quantities and how the items are rated.
Cables and transformers
Data halls run near their design load around the clock, so cable sizing has to account for continuous current, grouping in trays and the ambient in service corridors. MV feeders, LV distribution and the cables to each rack are usually separate packages with different construction.
Transformers are often specified for high efficiency because they run loaded continuously, and indoor installations may call for dry-type units. Confirm rating, vector group, losses, cooling and any harmonic allowance from the IT load with the electrical designer.
Fire performance and long-lead items
Specifications commonly require low-smoke, halogen-free or flame-retardant cables in occupied and IT spaces, and fire-survival cables for life-safety circuits such as fire alarm and emergency systems. State the fire standard for each cable type rather than one blanket requirement.
Transformers, MV switchgear and large quantities of MV cable usually carry the longest delivery times. Placing them first protects the commissioning date.
- Single-line diagram and redundancy level (N, N+1 or 2N)
- MV and LV cable schedules with installation method and fire requirement
- Transformer ratings, type, losses, cooling and vector group
- Cable accessories in scope: terminations, joints, lugs and glands
- Control room or monitoring display requirements, if any
- Site location, phasing and required dates
Sending the enquiry
UD Fomra Group supplies LV and MV cables, fire-survival cables, distribution transformers, cable accessories, control-room displays and Altos servers for data centre projects. Send the schedules and single-line diagram together, and mark anything still under design.
Early items can be quoted first if the full package is not ready, so long-lead equipment does not wait for the rest.