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Posted By Topic: Worksafe EV Charger Guidelines

JonoQC
Sep 08 2017 15:52

Looking through the EV charger guidelines, I notice there's a significant safety factor being applied to the rating of the common plugs/sockets used for this purpose.

What is the primary driving factor that leads to a requirement for such a safety factor? Is it old/shagged sockets, cheap crappy plugs/sockets or all of the above? It seems like the plug/socket standards themselves aren't incompatible with the idea that a plug/socket should be capable of constant use at rated. 3112 requiring temperature rise testing at 1.1x constant until at max temperature, for instance.

I'm wondering what this leaves the procedure for the most common scenario of an imported vehicle with a 16A EVSE cable? Currently the approach has been to put a 16A 60309 plug/socket on it and run with that. Under the guidelines, this would then need to be a 32A plug/socket?
   

pluto
Sep 08 2017 16:03

in very simple terms
EV draw the maximum current whenever connected to the supply, hence conservery rated socket outlets,a 10 amp socket outlet can't handle maximum loading of 10 A on a continuous basis.

The RCD can not be a standard Type A RCD due to the constanr d.c. residual current that flows in the a.c. supply cord.

You need to use standard plugs etc so that you will be able to connect to a wide rsnge of charging stations or locations.

There lots more to consider, some in is the WorkSafe guidelines but much of the detail is in a series of IEC standards IEC 61851.
   

JonoQC
Sep 08 2017 18:21

I get the issues around constant, long term current draw. My day job is EV charger R&D/hardware design.

I get the RCD aspect, although it's a little strange to see EV chargers 'singled out' when they're no different to most other switch-mode supply loads.

Public charging plug/socket commonality isn't at issue here because that's not going to be a problem solved by anything specified in 3112, 3123 or 60309. Much more likely to have a fixed wired EVSE with a cable/plug or a socket/byo cable from one of the valid choices in 62196.

61851 doesn't deal with the installation side of anything at all.

I'm not really even asking anything in the wider scope.

I'm really just wondering what the specific problem that's being solved here is. Is it cheap questionably-compliant plugs/sockets being used or old/shagged plug/sockets? The standards those plugs/sockets are tested to seem to support the idea that they can be used long term at rated current (rated current temperature rise tests).