Thanks Cyril and Robert for the clarification.
Andrej
If one fits this new Western Automation unit does it eliminate the need for an earth rod and external RCD? I have yet to fully wire up my ESVE but at the moment the only external protection is the standard 30mA RCD and MCB in the consumer unit.
Does the shop plan to sell this unit with its exciter coil and resistor?
The Western Automation unit will only eliminate the requirement for a Type-B RCD, you will still need an earth rod (or O-PEN device e.g. Matt:e) and a Type-A RCD and MCB or RCBO.
Any plans to sell an OpenESVE kit with this Western Automation product, or similar, integrated into the system? That would make the overall OpenESVE cost better as buying the existing Open ESVE plus the emonPi, plus an external DC RCD makes it more expensive, even in kit form, than some of the competition, which may have the DC detection built in (although I don’t have any real evidence of this.)
To be honest and as an engineer myself I’m struggling to see the big picture of what is protecting which failure modes and where.
There appears to be a gfci in OpenEVSE directly measuring the live and neutral imbalance going out to the plug that goes in the car. There is also an RCD requirement in the consumer unit feeding the device. When the relay operates, these are effectively connected to the same conductors so why do we need both.
Also I get that we need to monitor DC current leakage but is this just to avoid saturation of the RCD/GFCI devices or does it serve another purpose (if so what).
My problem is that I’m getting GFCI trips frequently and in order to identify the reasons I need to understand the purpose.
If this Western device is a good answer rather than Type B RCD then does someone have a working sketch of how it is implemented in OpenEVSE please
I’d be grateful for some guidance.
We’ve not been involved with the OpenEVSE project since 2023, we no longer resell OpenEVSE. However, I’ll do my best to answer:
You don’t need both, you can choose to disable the inbuilt GFCI if you wish. The RCD in the consumer unit is required to protect the cable if the cable run requires RCD protection. The inbuilt GFCI will trip faster than the RCD in the consumer unit and will reset itself and record the number of trips; therefore it’s adding convenience and functionality. There’s no harm in having both.
Correct, that is the purpose of DC current leakage protection.
Some OpenEVSEs have an overly sensitive GFCI and some vehicles, particularly older Renaults can trip the GFCI when they do their loop impedance test. The GFCI can be disabled if there’s upstream RCD protection at the consumer unit.
A Type-B RCD is the easiest solution, and probably the best. But some users have DIY integrated a Western device to avoid the cost of a Type-B RCD. The Western device is not officially supported by OpenEVSE, see:
If a Western device is used, to provide DC leakage, it should be used in conjunction with a Type-A RCD
You’re an absolute star thank you.
That is very helpful.
Regards
Daren Keates MSc
Principal Project Engineer - New Technology
Siemens Mobility Limited
Station Approach, Swanley, Kent, BR8 8JD, UK.
Mobile: +44 (0) 7921 247 011
E [email protected]