- Client: Alstom (for two UK high‑voltage cable manufacturers)
- Cooling Power: 66 kW
- Temperature Range: +10°C to +85°C with ±0.1 K tolerance
- Conductivity: DI quality maintained via mixed‑bed polishing resin (≤1 µS/cm typical; lower when required)
- System Capacity: Twin DI cooling loops with centralized chiller and cable test piece jackets
- Interesting System features: Custom PLC platform with external comms; Faraday cage around rig
Accelerated ageing of HV cables demands repeatable thermal cycles with very tight ramp and soak tolerances. GRE designed, manufactured and supplied paired DI water coolers tied to a centralized chiller, feeding cable test jackets to replicate accelerated aging. A thermally controlled dry housing protects adjacent electronics while a Faraday cage mitigates electromagnetic interference. The system control platform coordinates heating and cooling ramp profiles, enforces dwell times and logs all quality‑critical parameters, ensuring that the system can be tuned to replicate many test conditions.
To preserve low conductivity during aggressive and repeated cycling, the water conditioning loop employs mixed‑bed polishing, 0.2 μm filtration and UV sterilisation. Conductivity is monitored at multiple points; DI resin bottles are duty/standby with automatic switchover to minimise downtime.
GRE’s exhaustive design and analysis process ensured that the system balances cavitation margin with rapid flow changes: inverter‑driven pumps maintain differential pressure while soft‑start valves avoid thermal shock to the cable jackets. Materials used in the project are 316L stainless for all wetted parts and DI compatible seals, such as UHMPWE for temperature extremes. The result is a robust test utility that gives cable manufacturers the confidence to compress validation timelines without compromising data integrity.