Huber+Suhner issues statement on liquid-cooled charging cable safety issue

Liquid-cooled charger cable maker Huber+Suhner says a short-circuit in an older prototype CCS connector plug is the cause of a world-wide shutdown of 150+ kW electric vehicle charging sites.

The shutdown has disabled CCS charging at the large majority of Electrify America’s highway charging locations in the United States and has disabled some chargers that are part of the Ionity and Fastned networks in Europe. Scattered shutdowns have occurred at other sites and charging providers as well.

According to a new press release, “at a charging station on a test site of a customer in Germany, a short-circuit occurred with a HUBER+SUHNER cooled high-power charging cable. Nobody was injured in this incident. The short-circuit occurred in the plug. The cooling circuit with the synthetic, non-conductive coolant can be ruled out as the cause. The product in question is a first-generation prototype.

The statement says that the prototype cable was first made in 2017 and that the final production cables “differ from the first prototypes by, among other things, increased sealing.

According to company spokesperson Alex Rienitz, “increased sealing” does not refer to leakage of the non-conductive coolant fluid. Instead, it refers to ordinary water in the form of humidity (or perhaps condensation) getting into the connector plug.

The coolant fluid used is “a mixture of synthetic esters and additives. It has a high dielectric strength and can therefore not cause any short-circuiting. The term ‘increased sealing’ relates to outside humidity that could potentially diffuse into the connector”, he said.

Condensed water or surface moisture could occur if the plug is colder than the surrounding air. Rain or fog might cause similar problems on conventional connector plugs with inadequate sealing.

Pure water is not necessarily a good electrical conductor but this changes if it mixes with even small quantities of salts, dust, or other contaminates.

This information is consistent with previous reports that the incident involved a prototype cable and connector that differs in design from the final product that is installed at public charging locations.

See also: CCS liquid-cooled charging cable safety issue causes sudden widespread service shutdowns

Categories: Charging

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7 replies

  1. so when will they reopen?


    • Apparently, they are doing rigorous testing on the existing product to ensure that the safety problem that occurred on the older prototype cable design cannot be reproduced on the newer design.

      If the newer design being used by Electrify America and others tests out okay then the chargers will probably be back on within a few weeks or sooner. If the new tests discover a problem that requires a re-design and then extensive testing it could take months?

      Worst case, the liquid-cooled cables could be temporarily replaced with conventional 200A cables and could then operate at reduced but still pretty good power until better liquid-cooled cables are manufactured.

      There are also two other companies with their own separate liquid-cooled cable and connector designs, Phoenix Contact and ITT Cannon. I think those companies are close but not quite readily to deliver production cables to customers. Right now, Huber+Suhner is really the only supplier but that should change pretty soon.


  2. Difficult to say, for the timebeeing it seems to be a severe safaty issue leading to for sure to a recall campaign


  3. If you left your customer with a gun in their hands, without secure, you would say to them they all of them where close to shoot themselfes on face? Just wait and see, if it’s a previous and minor issue they will be back online soon, if not, you can start to perceive the dimension of problem.


  4. This sounds like normal growing pains. They’ll just weatherize the plugs better and move on. I do wonder what that short-circuit looked like, though. I get the feeling it must have been spectacular….

    Liked by 1 person

    • One hopes there was surveillance camera video… The product cables and plugs already have an improved weather sealing design than the older prototype that failed. Hopefully additional rigorous testing will determine that the existing cables at public charging sites are already good. The older failed cable was at a private test facility in Germany.


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