TT-98-129218-A
Power source
19
Chapter 3
Connecting power
3
Power source
There are different options for the power supply:
•
The 24 V DC ship supply provides power for the terminal.
•
A 12 V DC supply provides power for the terminal. Note that the maximum allowed source
impedance is much lower for a 12 V DC supply than for a 24 V DC supply.
•
A 230 V AC supply provides power through an AC/DC power supply.
Be aware of high start-up peak current: 20 A at 24 V, 5 ms.
The terminal is equipped with an internal 20 A Fuse, so no external fuse is necessary in order to
protect the terminal. However, in order to avoid short circuit in the power cable/connector, the
ship’s DC outlet should be protected by a 30 A fuse or circuit breaker.
Power cable selection
Source impedance
The length of the power cable depends on the type of cable used and the source impedance of the
DC power installation in the ship.
The maximum allowed source impedance depends on the utilization of the power range of the
terminal DC input (10.5 - 32 V DC; 14 - 5.5 A).
Select a power outlet from the DC system and measure the source impedance of the ship
installation as described in
Measuring the ship source impedance
on page 54 in Appendix B.
For further recommendations on power cable selection, see the next section.
Note
If the total impedance is higher than the limits stated in this
section, the terminal may become unstable and start to on/off
oscillate.
The total impedance is made up of the source impedance of
the ship power supply plus the impedance of connected cables
including connectors and joints where cables are extended.
