Marinus-DC is a family of subsea step-down converters (DC-DC) for marine and subsea systems that run from a high-voltage DC bus. Available for nominal 400 VDC and 800 VDC inputs, each converter steps the high-voltage bus down to an isolated 24 or 48 VDC output for auxiliary electronics, control systems, and rechargeable backup batteries. While high-voltage power is present, Marinus-DC supplies the low-voltage network and charges a connected ANIK battery pack; if the high-voltage source is lost, the battery keeps the low-voltage bus alive for uninterrupted operation. Every unit provides 4000 V galvanic isolation, high conversion efficiency, fast transient response, and integrated protection (over-voltage, under-voltage, over-current, short-circuit, and over-temperature) in a rugged, pressure-rated enclosure depth-rated to 6000 m.
- High-voltage DC step-downConverts a nominal 400 VDC or 800 VDC bus to a low-voltage 24 or 48 VDC output for auxiliary electronics, control systems, and battery charging.
- Galvanic isolation4000 V galvanic isolation between the high-voltage input and low-voltage output for safe, reliable integration.
- Backup battery supportCharges a connected ANIK battery pack while high-voltage power is available; the battery keeps the low-voltage bus alive if the source is lost.
- High efficiency & power densityProven high-density converter modules reduce heat, enclosure size, and system weight.
- Integrated protectionInput over-/under-voltage, output over-current, short-circuit, and over-temperature protection built in.
- Configurable outputSelectable output current (25 / 50 / 75 A) and regulated low-voltage options to match the application.
- Modular & scalableConverter modules can be paralleled for higher current and power.
- Rugged subsea enclosureAluminium or Titanium pressure-rated housings with customer-specified connectors (MCBH available), depth-rated to 6000 m.
Model range
| MAR-24 | MAR-48 | |
|---|---|---|
| Nominal input | 400 / 800 VDC | 400 / 800 VDC |
| Input range | 260–410 / 500–820 V | 260–410 / 500–820 V |
| Output voltage | 24 VDC | 48 VDC |
| Max output current | 25 / 50 / 75 A | 25 / 50 / 75 A |
| Galvanic isolation | 4000 VDC | 4000 VDC |
| Protection | OV/UV/OC/SC/OT | OV/UV/OC/SC/OT |
| Housing | Aluminium / Titanium | Aluminium / Titanium |
| Depth options | 300–6000 m | 300–6000 m |
- Type
- Subsea DC-DC step-down converter
- Input voltage
- 400 / 800 VDC nominal (260–410 / 500–820 V)
- Output voltage
- 24 or 48 VDC (adjustable)
- Max output current
- 25 / 50 / 75 A
- Galvanic isolation
- 4000 VDC
- Protection
- OV / UV / OC / SC / OT
- Backup charging
- 5–65 V adjustable (ANIK pack)
- Connectors
- Customer-defined (MCBH available)
- Housing
- Aluminium / Titanium
- Depth rating
- 300 / 1000 / 2000 / 6000 m
Specifications subject to change without notice.
FAQ
Subsea step-down converter FAQs
What is a subsea step-down converter?
A subsea step-down converter takes a high-voltage DC bus and converts it to a lower, usable DC voltage underwater. Marinus-DC steps a 400 or 800 VDC bus down to an isolated 24 or 48 VDC output.
What input and output voltages does Marinus-DC support?
Nominal inputs of 400 VDC (260–410 V) and 800 VDC (500–820 V), with adjustable 24 or 48 VDC outputs at up to 75 A.
Does it provide galvanic isolation?
Yes. Marinus-DC provides 4000 V galvanic isolation between the high-voltage input and the low-voltage output.
Can it charge and back up a battery?
Yes. While the high-voltage bus is present it charges a connected ANIK battery pack; if the bus is lost, the battery keeps the low-voltage system running for uninterrupted operation.
How deep can Marinus-DC operate?
Standard depth ratings are 300, 1000, 2000, and 6000 m, in Aluminium or Titanium housings with customer-specified (including MCBH) connectors.
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