Overview

The Hella Marine 998572001 is a two-group light dimmer for 12V and 24V DC systems, with an 8 to 30 V DC input range.

It uses PWM dimming for one or two separate lighting groups, with a jumper that sets one-group mode (both outputs controlled together) or two-group mode (each output controlled independently). Each output is rated for up to 100W on a 12V system or 200W on a 24V system, and when both groups are combined into one the unit supports up to 200W at 12V or 400W at 24V.

Soft-start and internal voltage regulation help protect filament and halogen bulbs when charging voltage climbs above nominal system voltage, and the built-in low-voltage protection shuts the lights off to reduce the chance of deep battery discharge.

Key features

• 8 to 30 V DC input for use on 12V or 24V boats
• Two dimming outputs with jumper-selectable one-group or two-group operation
• Load capacity: 100W per output at 12V (200W total) or 200W per output at 24V (400W total)
• PWM dimming for compatible LED loads and for filament or halogen bulbs
• Soft-start to reduce start-up surge on halogen and help extend bulb life
• Low-voltage cutoff turns lights off below 9V (12V system) or 18V (24V system); re-enables when battery reaches 12V or 24V
• Protection and fusing: 2 x 10A fuses, plus overload and temperature protection
• Compact module size: 99 x 89 x 41 mm; weight 140 g

Installation and setup

Mount the module on a solid surface in a dry, ventilated location. The unit is controlled by momentary, normally-open pulse switches, and multiple switches can be wired in parallel per group when you want control from more than one location.

Select one-group or two-group operation by setting the onboard jumper. In either mode, plan your wiring so the lighting load is divided across the two outputs rather than piling everything onto one circuit.

Electrical and lighting compatibility

This dimmer outputs PWM, so the connected lights need to be compatible with PWM dimming. With LED lighting, that usually means the lamp or driver accepts PWM input; if a fixture has an external driver, confirm the driver supports PWM to avoid flicker or limited dimming range.

For boats that still run filament or halogen bulbs, the soft-start function helps manage inrush current at switch-on, and the internal regulation helps keep the lighting circuit closer to nominal 12V or 24V when the alternator or charger is pushing the system higher.

Use on board

This setup fits well when you want separate control of two zones such as cabin and cockpit, or saloon lighting and berth lighting, while keeping the switching simple with momentary push buttons. It also suits mixed refit jobs where some circuits are LED and others are still bulb-based, as long as the LED fixtures are PWM-dimmable.