case studies


Case Study 1.

Remedial Action

As all parts of the install required attention and upgrade, all cabling was removed and equipment
was disconnected and tested. Much cabling had been run in the bilge and the copper was found to
be oxidised in many cases.

Main DC Circuits

-batteries were tested. The isolator switch and inverter were moved to the aft cabin bulkhead
which is much closer to the batteries (pic).
-a busbar was fitted for the main negative returns (pic)
-main DC fuses were installed for the inverter and DC distribution (pic), and all main ungrounded
-DC cables were sheathed in flexible conduit or spiral binding.
-the starter circuit was rewired (pic), and the starter and blower circuits controlled by relays.(pic)

Engine Circuits

Problems had been caused in the past due to lack of monitoring of engine function which had led
to failure due to lack of coolant. A new oil pressure gauge was fitted, replacement fuel gauge and sender, and an alarm system installed to alert operators to low oil pressure or excessive temperature.

Engine circuits were connected to the instrument panel by a multicore cable with higher current functions controlled by relays.

DC Power Distribution

-the existing instrument panel was retained. Switch panels were removed and replaced by Vetus P8 units using standard ATC fuses (pic)
-12 volt cigar-type sockets were fitted for portable items such as phone chargers etc
-ATC fuses were fitted for all circuits, circuits were grouped into direct and switched 24V and
12V from the DC-DC converter (pic)
-the panel was wired such that access was easy, and removal could be accomplished via the use of multiway connectors (pic)

Bilge Pumps

The avoidance of a fully laden barge sinking in the canal was of paramount importance, and it was required to install 24V bilge pumps on direct circuits to cover all four watertight compartments (pic of fwd pump). This involved cabling through bulkheads without compromising the watertight seals, and avoiding large volt drop issues at the forward end. (pic)
Pumps were monitored by an LED display and audible alarm at the instrument panel.

AC System

The 1500W inverter was resited and connected to a twin RCD protected socket on the port side of the wheelhouse. A boat earth point was installed to ground the AC earth and DC negative to the steel structure.

Outside Circuits

Forward circuits previously run outside for the working lights were resited inside for protection and cabling was terminated in IP55 boxes (pic).


The installation/upgrade was completed on time and within budget. The client is very happy with the result and the system has proved reliable and robust in operation.