TP4 -

DESIGN GUIDELINES FOR HIGH-VOLTAGE WIRING HARNESSES

Extension of the standard to include high-voltage wiring harnesses

In the first edition, DIN 72036 was limited to the use of low-voltage wiring harnesses with unshielded cables. In a vehicle, however, a large number of applications are served, which in turn require specific components and cables.
One of these applications is electric driving and the high-voltage systems developed for this purpose, which currently use up to 800V on board voltage. The various core components such as the battery, motors and power electronics are connected with special high-voltage cable sets. These are easily recognizable in orange.

Initial situation and motivation

Developments in the field of electric driving and the associated need to massively increase the voltage level in the vehicle are leading to a veritable boom in new high-voltage components and manufacturing processes. Due to the enormous speed at which this development is taking place, manufacturing aspects that allow simple and automated production are often not given sufficient consideration.

At present, OEMs and manufacturers in particular have to deal with a whole range of possible technologies and, unlike in the low-voltage sector, they cannot rely on decades of experience in the development and construction of cable harnesses. In particular, the much larger cross-sections and the use of shielded cables pose new challenges for production.

It is therefore a good time to promote the emerging consolidation of technologies in wire harness production towards full automation with the expansion of DIN 72036 to include high-voltage wire harnesses.

Current focus of work

In the first step, all low-voltage design guidelines are checked and evaluated for their direct applicability to high-voltage. There are four different assessments.

• The design guideline is applicable without restriction and without modification.
• The design guideline is applicable with only a few changes.
• The design guideline is transferable with comprehensive revision.
• The design guideline is not relevant for high-voltage.

This assessment results in a worklist that is to be completed by the next update of the standard. The design guidelines that require few to no changes are the easiest to implement. Here, either only the application level is added or a few changes are made to the content. Ideally, the design guideline can remain valid for LV despite these few changes.
In the case of major changes, a new design guideline is derived and developed. This requires intensive coordination within the TP and with other TPs, as the applicability of new design guidelines to low-voltage and high-frequency wiring harnesses must be clarified.

Outlook

With the structured recording of common components and production processes of a HV wiring harness and their systematic linking, gaps in the standard can be uncovered that can be closed in a targeted manner with new design guidelines. The aim here is to record as comprehensively as possible all aspects that are necessary for the fully automated production of HV wiring harnesses.