ABB 216NG63A Auxiliary DC Supply Unit

The ABB 216NG63A Auxiliary DC Supply Unit is a galvanically isolated DC/DC converter built for the REG216 / REC216 generator protection system. It steps down the station battery voltage (220/250 V DC class) to a regulated 24 V DC rail, which feeds all electronic modules and I/O units on the 216MB66 rack via the B448C parallel bus.

Key Features

• Wide input range: 220/250 V DC nominal (165–312.5 V DC, ±25%)
• Regulated 24 V DC output, galvanically isolated from the station battery
• Redundancy-ready: two units per rack share the USA / USB supply lines
• Front-panel green LEDs: U IN (input present), U OUT (24 V present), plus I/O ON/OFF switch
• Rear plug-in jumpers A/B select which redundant bus lines (USA / USB) are fed
• Integrated 1.6 A slow input fuse; output is short-circuit and overload proof
• Plug-in module, 3 standard divisions (3T) wide

Technical Specifications

Installation Notes

1. Insert the unit into rack divisions 1–3 or 19–21 on the 216MB66 rack; the B448C bus engages at the rear.
2. For single-supply racks, install both jumpers A and B so the unit feeds both USA and USB.
3. For redundant two-unit racks, assign one unit to USA and the other to USB per the plant wiring diagram; both units may connect to the same or two independent station batteries.
4. Verify U IN and U OUT LEDs are both green after switching I to ON; if U OUT is dark, check the 24 V output and jumpers.
5. The K100 “24 V failure” relay signals loss of auxiliary supply to the system alarm chain.

Common Questions

What station battery voltage does this unit accept? The 216NG63A is rated for 220/250 V DC station batteries, operating down to 165 V and up to 312.5 V DC. For 110/125 V DC batteries, use the 216NG62 variant; for 24/48 V systems, use the 216NG61.

Can two units run in parallel? Yes. Two 216NG63A units can be installed redundantly in the same rack, each feeding one redundant 24 V rail (USA or USB). As long as either rail is present, all protection functions continue to operate.

What happens if the 24 V supply drops? Stored protection settings and user logic are retained (no battery-backed RAM loss). The K100 relay triggers a “24 V failure” alarm via the SML line, and the system raises a general alarm — but no protection function outputs are energized.