Active product line

Delta ESR-48 series rectifier modules

Delta owns both its own ESR line and, since 2015, the Eltek brand. If you run a mixed estate, that is useful: one manufacturer group covers a large share of the 48V telecom base, and cross-referencing between the two catalogues is often where a workable answer comes from.

Availability & lifecycle

Active. The ESR family remains a current Delta product line, with variants differing in current rating and cooling.

Models we are asked for

Part number	Model	Indicative specification
ESR-48/56	Delta ESR-48/56	48 V · 56 A class · rack-mounted telecom rectifier
ESR-48/56AC	Delta ESR-48/56AC	48 V · 56 A · AC input variant
—	Delta ESR series shelves	Subracks and DC power systems for the ESR family

Specifications are indicative and published by the manufacturer. Availability, exact revision and lead time are confirmed in the written quotation.

Where it is used

Telecom operator DC plants
Fiber and broadband cabinets
Data-centre 48V distribution
Industrial DC systems

What to send us

The full ESR designation including the suffix — ESR-48/56 and ESR-48/56AC are different orderable items — plus the shelf model.

Compatibility notes

Because Delta owns Eltek, a Delta-group cross-reference sometimes solves a Flatpack shortage and vice versa. Send both the module and the shelf and we will check the group catalogue.

Common questions about this family

What is the difference between the ESR-48/56 and the ESR-48/56AC?

They are different orderable items despite the near-identical designation — the suffix matters. Always quote the full designation including the suffix, plus the shelf model, or you risk receiving a module that does not match your plant.

Does Delta still produce the ESR series?

Yes, ESR remains a current Delta product line, with variants differing in current rating and cooling. Delta has also owned the Eltek brand since 2015, so a cross-reference inside the Delta group sometimes resolves a Flatpack shortage — and the other way round.