SAFE ELECTRICAL CONNECTIONS FOR REFRIGERATED VEHICLES

THE REQUIREMENT FOR THE ELECTRICAL CHARGING OF REFRIGERATED TRAILER UNITS IS INCREASING

In France, heavy-duty and light-duty vehicles account for 22% and 19% respectively of the GHG (Green House Gas) emissions of the transport sector1. The transport sector being itself the highest contributor to GHG emissions with 31% of the country’s emissions.

The potential for reductions has already been identified for these types of vehicles. For example, restricting vehicles road speeds, the integration of start and stop systems on vehicle engines or the correct management of the tyres used on goods vehicles, these are efficient and recognised methods to implement. More specifically related to refrigerated vehicles, there are additional actions which can optimise the overall consumption of the vehicles. Indeed, refrigerated vehicles are similar to light or medium duty vehicles that have been improved by adding thermal isolation (creating a refrigerated box) and a refrigeration unit (diesel or electric supply).

As a result, specific actions for refrigerated vehicles target the refrigeration system and encourage high efficiency systems to be used: adequate systems in terms of refrigeration capacity, enhanced maintenance, thermal isolation, and electric charging at base.

With typical diesel consumption around 0.4 L/kWh2 of refrigerated capacity, there is no doubt electric charging of refrigerated vehicles represents a great opportunity to save money and reduce environmental impact. Charging the auxiliary battery when the vehicle is parked is a big advantage and this solution requires specific power connectors.

 

HANDLING RISKS RELATED TO ELECTRICAL POWER SUPPLY OF REFRIGERATION UNITS

Power connection on logistics site always represents a risk for operators, goods and the electrical installation. Thanks to MARECHAL®’s experience in this field, we have identified three main risks areas which with the correct implementation of equipment avoids accidental damage to installations and worse injury to operators.

  • Moving vehicles

Any vehicle movement during loading or unloading can result in injury to operators, damage to the installation or goods being loaded (forklifts, finished products etc...) A vehicle may move for example when the truck driver drives away thinking the loading process is completed. Damage can also occur if the power supply is not disconnected before the truck is moved.

 


These kinds of events can cause material loss or potential injury to operators due to the electrical installation being damaged.


  • Power connection handling

Over time, the repeated handling of power connectors can effect on their performance. For example, damage to the electrical contacts due to arcing when connecting under load, connections working loose because of moving cables. These issues can impact the quality of the electrical connection and may create safety hazards (damage to cables or plug contacts, exposed live conductors) which will cause problems for the normal operation of equipment.


  • Low performance of power connections in normal operation

Using standard products often creates issues that are inherent to the technology used. Increase of contact resistance, corrosion will happen with pins and sleeve technology resulting in temperature rise at the connection surface, higher power consumption and a shorter operating life of the installation.

 

MARECHAL® SOLUTIONS

The main objectives of MARECHAL ELECTRIC are to avoid human error, to ensure electrical installations safe and to help reduce energy consumption. This is what lead to the development of MARECHAL® solutions for vehicles. We provide plugs and sockets solutions which take operating conditions into account to ensure improved performance for operators.

All MARECHAL® solutions are designed to allow disconnection under load, self-ejection of the plug and to reduce the electrical resistance of the connection. Disconnection under load and low electrical resistance are achieved thanks to the butt-contact technology which features silver-nickel tips (DECONTACTOR™ Technology (marechal.com)). MARECHAL ELECTRIC offers two types of technologies for automatic ejection: electromagnetic (with the RETTBOX® S range) and mechanical ejection using the DECONTACTOR DSN, DS range of connectors.

 

  • Electromagnetic Ejection

RETTBOX® S is an electromagnetic self-eject socket outlet system which provides the user with great performance. A SMART compact design with rounded corners which features visual indication LEDS and a manual eject button. A Simple solution, easy to install and to use. A Safe solution with the reliable MARECHAL® technology.







  • Mechanical ejection

The mechanical ejection system features a simple 'shark fin' latch which is addedadded to the male or female side of a DECONTACTOR™ connector. A tension cord is attached to the latch which is released if tension is applied to the cord. This results in the mechanical ejection of the mobile part of the plug and socket system.

 
Ejection mecanique_Rettbox s               Ejection mecanique_Rettbox s



1 Source : 2019 figure, Ministère de la Transition Écologique et Solidaire

2 Source : Frigoblock