Training, Installation & Service Manual - Livewire Connections Ltd

5.2.3 Power cable recommendations
5.2.3.1 Overview
Figure 5-1: Measuring the ship source impedance
The ACU is delivered with a power connector (PCB plug-in
connector, female plug, Weidmuller, Part number 1930050000),
which accepts wires up to AWG10/6 mm 2 .
• When installing the power cable, install positive and negative
supply wires closely together side by side to keep cable
inductance low.
• Ensure that cable inductance for the selected cable at the desired
length is less than 50 uH. Approximately 50 m maximum length.
Power cable selection
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Connecting power
5.2.3.2 Calculating the maximum power cable length
For 24 VDC operation, the total impedance must be max. 60 mOhm
(R max ), including the source impedance in the ship installation
(R source ).
The total impedance is made up of the following:
• Source impedance in the ship installation
• Impedance of the selected power cable
To calculate the maximum cable extension, do as follows:
1. First measure the source impedance in the ship installation as
shown in Measuring the ship source impedance on page 5-2.
2. Find the resistance per meter (Rwire) for the cable type you are
going to use.
For 4 mm 2 /AWG 11, the value is 4.8 mOhm/m at 55°C
For 6 mm 2 /AWG 10, the value is 3.8 mOhm/m at 55°C
98-133966-E2 Chapter 5: Connecting power 5-3