The MD04UPS is a 24 V dc Uninterruptible Power Supply (UPS) designed to provide a backup supply for vital ship’s equipment such as Heading Repeaters, in the event of a main power supply failure. Housed in a rugged steel enclosure and designed for low maintenance operation, the MD04UPS will supply electrical power to a Marine Data
installation for a period of at least 45 minutes* following the loss of the main power supply. Suitable installations for safeguarding include: Heading Repeaters, Heading Monitors, Compass Comparators, Transmitting Magnetic Compass Systems (TMC) and Rudder Angle Indicator Systems. The integral battery is automatically recharged once the main power supply is restored. Indicators show Main Supply Present, Backup Supply in Use and Backup Supply Charge State OK. Indication is visual with provision for an external alarm via a loop circuit (voltage-free switch contacts). The MD04UPS from Marine Data: flexible in application, easy to install and simple to maintain.


• Maintains a 24 V dc Power Supply for Vital Ship’s Equipment
• Output Current up to 6 A
• Switches from Main 24 V dc Supply to Integral Battery Backup Supply
• Automatic, Uninterrupted Changeover when Main Supply Fails
• Automatic Charge Maintenance of Integral Battery
• UPS Hold-Up Time: 45 minutes* (minimum) at 1 A
• Indicator / Alarm Outputs for Operational Status


• Safeguards the electrical supply of vital ship’s equipment


MD81 – 115 V / 230 V ac to 24 V dc Marine power supply
MD86HCU – Heading Comparator Unit
Transmitting Heading Device (THD) Systems (TMC and EMC)
The complete range of Marine Data Heading Repeaters & Monitors



Weight: 8.25 kg
Dimensions: H 256 mm (excl. cables & glands); W 284 mm (incl. fixings); D 186 mm
Mounting: Bulkhead mounted
1 x Power input cable;
1 x Power output cable;
1 x Status monitoring cable;
Internal screw terminals via cable glands
Construction: Steel enclosure
Finish: RAL9005 Jet Black, fine texture


Power Input: 22 V to 29 V dc 6 W (+ output load)
Power Output: Nominal 24 V dc @ up to 6 A
Status Output: LED Indication / Volt Free Contacts


Summary: Automatic changeover to battery backup supply;Automatic recharging of integral battery; Status and Alarm indications
Performance: At least 45 minutes backup @1 A load
Display: LED Indicators; internal via front view window
Indications: Normal Operation (main supply in use); >85% Charge (battery charged); Floating operation (battery in use); Alarm Signal (battery not ready)


IP rating: IP32
Operating temp: -10°C to +50°C (Ventilation required)
Compass: Safe Distance: 200 cm


Complies with:
Protection Class III to EN60950
IEC 364-4-41 (VDE 0100 Part 410)
IEC 536 (VDE 0106 Part 1)
EN 60204-1 (VDE 0113 Part 1)
IEC 61131; UL508, CSA C22.2
RI suppression to EN55022, limit-value curve B
Interference immunity to EN 61000-6-2