Rules and Guidelines
Want to participate in the discussions? Please read our Community Rules and Guidelines. Need some help? Visit Support and Answers.

  • State Helpful Answer
  • Locked Locked
  • Replies 7 replies
  • Subscribers 34 subscribers
  • Views 1141 views
  • Users 0 members are here
Options
You may also be interested in
This discussion is locked.
You cannot post a reply to this discussion. If you have a question start a new discussion

RCD for use with DC leakage

Mspark

Proposed installation of EV charge point with two socket outlets on same charger. Manufacturer claims maximum DC leakage current no more than 6mA from charger.

Installation is a small hill farm with multiple armoured submains to outbuildings. Whole site is TT earthing system with an existing 100mA (s) Type A RCD main switch.

One outbuilding has 4kW Solar PV with inverter no simple separation manufacturer claims maximum DC leakage current no more than 6mA.

With the addition of an EV charge point to an existing submain on a remote building there is the possibility of EV leakage 6mA + PV leakage 6mA =12mA of DC leakage current which may blind the RCD main switch. I have tried to locate a 100A single phase time delayed type B RCD suitable for operation by an ordinary person but have failed however I have found a Schneider A9R35291 100A 300mA  (s) type A super immunized which is suitable for use with DC currents up to 60mA.

The Schneider information says it has proposed another possibility with the use of this product and does fit with my installation requirements.

I'm not sure where I stand when the wording says proposed another possibility.

Parents
  • 0

    I guess another option (provided you consider each 6mA only to occur after a fault, rather than in ordinary operating conditions) is an A-type upstream together with an RDC-DD. (Not sure if the regs have let that approach escape from 722 yet, but the physics is surely the same.)

       - Andy.

  • 0 in reply to AJJewsbury

    I was under the impression that the DC leakage happens under normal operating conditions and it is only when the leakage exceeds 6mA that the internal RDC-DD operates to stop blinding of an upstream RCD.

Reply
  • 0 in reply to AJJewsbury

    I was under the impression that the DC leakage happens under normal operating conditions and it is only when the leakage exceeds 6mA that the internal RDC-DD operates to stop blinding of an upstream RCD.

Children
No Data

Join us to get the best from IET EngX.

Joining EngX lets you personalise your experience so you stay up to date on the topics that interest you, plus you’ll be able to make connections who are looking to collaborate, exchange ideas and more.

Join us Not now

Community Rules & Guidelines