Supporting members to mitigate their risk when considering carriage of additional reefers using Y-splitters

The club is seeing an increasing number of requests from members who are considering the use of Y-splitters in order to increase the reefer capacity on their containerships beyond their designed limit. However, when doing so, there is a risk of overloading the power cables. This would generate excess heat and increase the potential of fire. This risk is further enhanced by the absence of frequent monitoring and review, of the condition of the extra cabling, sockets, plugs and reefers by the crew.

The club fully understands the commercial attractiveness of such opportunity and, as always, is willing to support members to manage and mitigate their risks. This article is aimed at providing considerations that members should have in mind when conducting their own risk assessment for carriage of additional reefers beyond the ship’s designated capacity.

1. Comparison of electrical load exerted by the additional reefers against capacity of power source

There is a reason why ships are assigned to carry a specific maximum number of reefers. This takes into account the generator capacity against the loads exerted by cargo (reefers), machinery and domestic supply, and an additional safety margin.

While the latest reefer designs are known to be far more efficient and consume less energy than previous models, many container fleets still have a big share of older reefer versions in use today. Such old reefers tend to draw a much higher current than the newer designs. There is also a need to consider reduced efficiency of the generators due to ship’s age.

The power consumption of a reefer container depends on a number of factors including weather and storage conditions, container type, and may vary significantly depending on the type of commodity, i.e., chilled or frozen goods. Generally, the higher the internal temperature, the higher the electrical power consumption. Once the cargo has been cooled, the average power consumption falls. In cases where there are several hot reefer containers, when these are turned on at the same time, there is a possibility that the current drawn may exceed the capacity of the power source.

It could get even more crucial in cases when the ship is experiencing adverse weather conditions or maneuvering in congested waters and may require additional power for bow thruster or other auxiliaries like additional steering motors, auxiliary blowers, etc.

The club is aware of a case whereby an agreement was reached between the owners and charterers, for a vessel using Y-splitters, that bow thruster will not be used during manoeuvring and that charterers will pay for an extra tug. Essentially, it needs to be ensured that the total load does not exceed the designed rating at any time.

2. Safety aspects related to the use of Y-splitters

Y-splitters allow multiple reefer cords to connect to a single power source receptacle; however, there is a risk of power outtage/tripping, blackout, fire and other consequential liabilities (like cargo damage, navigational, pollution, etc) if the loads exceed the capacity of the generators (or power pack, if available).

There is also a need to consider the rated capacity of the Y-splitters, reefer extension cords, sockets and plug points – these should not be exceeded at any time.

Y-splitters when improperly handled can bypass the integrated safety designs of the receptacle panel – one should not connect or disconnect reefer plugs to a splitter while it is energized. It is recommended that the reefer plugs are connected to the splitter first and then the power source can be connected and energized.

The splitter and associated equipment should be in a sound condition and able to withstand shock load and power surge. Multiple Y-splitters on the same circuit should not be used and if required, the ship’s generator capacity shall be increased safely by using power packs.

One way of distributing the electrical load is by plugging a chilled and frozen commodity reefer on the same splitter. However, knowing that the planning is generally done on the basis of load and discharge ports, it might not always be possible to plan the reefers or distribute the loads effectively. Alternatively, some operators prefer to use ‘splitter box’ as it safely regulates the power to the reefers (and prevents both reefers from switching on at the same time).

Category: Loss Prevention