DC Power cable
To ensure reliable and safe operation it is important to select and install suitably rated DC power cabling between the Blue Smart IP22 Charger and the battery/batteries.
Cable type/specification selection should consider the following aspects:
Conductor material and cross sectional area
Conductor material and cross sectional area effects the resistance of a cable per unit length, and accordingly determines the maximum current capability/rating, as well as the power loss / voltage drop over the total cable length.
To prevent overheating of the cable and/or interfacing equipment, select high quality power cable with copper conductors and a conductor cross sectional area appropriately sized for the application.
The cable manufacturers maximum current rating for the cable (after applying any de-rating factors applicable to the installation) must exceed the maximum operating current possible within the system, and the cable must also be capable to safely withstand the fault current required to blow the fuse / trip the circuit breaker.
To prevent high power loss and operational issues due to excessive voltage drop, design the system layout so that cable lengths are as short as possible and if needed increase conductor cross sectional area to reduce voltage drop to an acceptable level.
If needed, it is recommended to increase conductor cross sectional area so that the voltage drop over the total cable length is below ~0.5V and ~3% at maximum operating current.
Strand diameter
Strand diameter effects the contact area / resistance and accordingly determines the amount heat generated at terminations, as well as the flexibility capability/rating of the cable.
To prevent overheating of the cable and/or interfacing equipment at/near terminations, select high quality power cable with fine multi-stranded copper conductors.
In order to maximise contact area and minimise resistance at terminations, the diameter of each individual copper strand must not exceed 0.4mm (0.016 inch) or a surface area of 0.125mm² (AWG26).
If cable with a thicker strand diameter is used, the contact area at the interface between the conductor strands and termination will be insufficient and cause excessive resistance. A high resistance electrical connection will generate substantial heat when operating under load and result in severe overheating or potentially a fire.
To enable easy cable routing with tight bends and prevent failure of the cable and/or interfacing equipment due to excessive force/stress at terminations and/or cyclic fatigue, select high quality power cable specifically designed for applications requiring high flexibility.
It is recommended to use high quality power cable with a flexibility class rating of 5 or higher (according to VDE 0295, IEC 60228 and BS6360).
Insulation type
Insulation type effects the maximum temperature capability/rating and accordingly the maximum current capability/rating, as well as the maximum voltage isolation capability/rating of a cable.
To prevent overheating of the cable insulation, select high quality power cable with an insulation temperature rating appropriate for the installation.
The cable manufacturers insulation temperature rating must exceed the maximum projected temperature for the installation, when considering the combination of maximum possible surrounding temperature and temperature rise due the heat generated by the cable itself under maximum load.
It is recommended to use high quality power cable with a maximum temperature rating of at least 90°C (194°F).
To ensure robust electrical isolation, select high quality power cable with an insulation voltage rating appropriate for the maximum operating voltage of the system.
It is recommended to use high quality power cable with a maximum voltage rating of 0.6/1kV.
Refer to the table below for the recommended minimum cable cross sectional area / gauge in relation to cable length (one way length between charger and battery):