Sperry Marine 1885693

The Sperry Marine 1885693 (often associated with cage code 03956) is a Pilot Watch Alarm unit, also known as a Bridge Navigational Watch Alarm System (BNWAS) component.

Given your previous inquiries about specific PCBs for telephone exchanges and ABB modules, it appears you are working on a ship’s bridge console or a marine communication/safety rack. This unit is a critical safety device designed to monitor the awareness of the Officer of the Watch (OOW).

Core Function & Operation

The Pilot Watch Alarm ensures that the bridge is never left unattended or that the pilot has not become incapacitated.

• The Timer: The unit operates on a countdown timer (typically adjustable between 3 and 12 minutes).

• The Reset: The pilot must press a “Reset” button or trigger a motion sensor at regular intervals to restart the timer.

• The Alarm Sequence:

  1. Visual Warning: A flashing light on the console.

  2. Stage 1 Alarm: An audible tone on the bridge.

  3. Stage 2 Alarm: If not reset, the alarm sounds in the Captain’s cabin and other officer quarters.

  4. Stage 3 Alarm: If still not reset, the alarm sounds throughout the entire ship (General Alarm).

Technical Specifications

• Part Number: 1885693

• Manufacturer CAGE Code: 03956 (Northrop Grumman / Sperry Marine)

• System Integration: This unit typically interfaces with the ship’s VDR (Voyage Data Recorder) to log every time the alarm is triggered or reset.

• Input/Output: It usually takes a 24V DC input (standard marine emergency power) and has dry-contact relay outputs to trigger external sirens.

Common Issues & Troubleshooting

If you are repairing or testing this specific unit, look for these common faults:

• Keypad/Button Failure: Because the “Reset” button is pressed thousands of times, the tactile switch on the internal PCB often wears out.

• Backlight Failure: The internal lamps or LEDs that illuminate the “Watch Alarm” text often burn out, making it hard to see the status in the dark.

• Timer Drift: In older units, the internal timing crystal or capacitors can age, causing the alarm intervals to become inconsistent.

Integration with your other boards

On a vessel, the ABB RQBA 040 you mentioned earlier might be providing the redundant power to this Sperry Marine unit. If the Pilot Watch Alarm is showing a “Power Fail” light, you should check the output of the ABB diode unit.

Comparison with Modern Standards

While the 1885693 is a reliable legacy unit, modern IMO (International Maritime Organization) regulations for BNWAS are more stringent. If you are performing a major refit, check if this unit still meets the latest IEC 62616 standards for your specific vessel class.