Hephaestus

Where it sits

Utility power arrives as medium-voltage AC and is converted once, at a central rectifier plant, onto an 800 VDC overhead busway. Every rack feed leaving that busway drops through one Hephaestus protected feeder. A redundant rack takes two, one per path.

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Today’s feeders can’t do this

Racks today run on 54 volts, protected by ordinary mechanical breakers and fuses. At one megawatt that would mean 18,519 amps, so the industry is moving to 800 VDC, where the same rack draws 1,250. But 800 volts of direct current has no zero crossing to extinguish an arc, and a mechanical breaker takes milliseconds to open. Faults have to be cleared in microseconds, by silicon.

The parts exist. The product doesn’t. Nobody ships the integrated, certified feeder that stands between the bus and the rack.

Hephaestus is that integration.

Hephaestus engineering alpha

Nominal voltage

800 VDC

Component voltage class

1,000 VDC

Fault interruption

Solid-state, < 25 µs

Continuous current

1,600 to 2,000 A class

Capacity at 800 V

1.28 to 1.60 MW per feed

Cooling

Liquid, water/glycol

Feeds

One per module, A/B via paired modules

Functions

Protection, isolation, precharge, discharge, monitoring

Ratings are an operating envelope, not a single marketing number. The final label states the validated voltage window, coolant conditions, and overload profile. The full interface control document, covering bus, rack, cooling, and control connections, is available to design partners.

From bench to pilot

July 2027.

Deploying 800 VDC? Build it with us

We’re selecting design partners for the Hephaestus engineering alpha. Partners set the rating envelope, shape the interface spec, and receive the first pilot units.