Is there a 20 AMP timer for 3 pin charger

[The Waiheke Don]

My sparky caught something just in time because the timer I had to charge my iMiEV (at the lowest KW charging rate after midnight) wasn't suitable and was actually starting to crack it's moulded case through excessive heat buildup I guess. It was the most expensive one offered at the contractor's electrical shop ($45) but still 10 amps.

My sparky said he could build a rugged timer but estimated it would cost $300 because a relay is needed to switch on the mains power or something like that.

We have 400+ Nissan Leafs on Waiheke and the vast majority have 3 pin charging. Seems like there would be a reasonable market here and in NZ for a 20 amp timer. There are a few things on AliExpress, etc. but might not meet our insurance / safety specifications.

Suggestions most welcome..

 

[coulomb]

It would be a whole lot easier, cheaper, and kinder to the On Board Charger to switch the control pilot signal between the EVSE (AC "charger") and the car. Unfortunately, it's not as convenient.

My understanding is that switching the AC power to the on-board charger mechanically (with a switch, relay, or timer with relay) will cause a huge inductive kickback that will damage the switch/relay and eventually the on-board charger, at huge expense.

Switching the control pilot signal will stop the charge electronically, where there is a patch for the inductor's energy to be dissipated safely or sent on to the battery.

 

[kiev]

Why there are no timers rated above 10A: ima gonna guess that the 3-pin cords, sockets and circuits are running on 120vac out of the standard outlets with 2 vertical blades and a round ground pin.

The circuit breaker for those is rated at 15A, and by the 80% rule is good for 12A.

If you want a 20A [ruled to 16A] breaker circuit, then the outlets will have one vertical and one horizontal blade plus the ground. Not many folks have those in their homes, so not much of a market for 20A timer except commercial.

The Leaves have a built-in timer that allows setting the charge time. Unfortunately we don't have that except thru using the Remote, if the car had that option.

As with @coulomb, i don't recommend just pulling the plug or snapping the power off with a relay--seen too many failed OBCs in the troubleshooting and repair thread.

p.s. that minicab is awesome

 

[Piki]

I think the author of the original post refers to using a timer for starting the charging after midnight, not terminating it in the middle. So I don’t think there is any risk of using a timer for this application. It would be the same as to connect the cable first to the car and then to the outlet. The charging will anyway start the ordinary way. I actually use a timer that way for minimizing the car to sit with 100% charge overnight, set it so that the charging ends few hours before I need to drive in the morning. I use a rather cheap (probably 20 €) timer, bought in a supermarket, probably not the best possible quality, but not the AliExpress crap. It is rated for 16A continuous (not sure for how long). Charging at 8A 230 VAC is no problem, no heating.

 

[coulomb]

I think the author of the original post refers to using a timer for starting the charging after midnight, not terminating it in the middle.

Yes, the problem is turning off, not turning on, the On Board Charger. So if you can guarantee that you'll never stop a charge with the timer, then that's fine.