Speak EV - Electric Car Forums banner

1 - 14 of 14 Posts

·
Registered
Joined
·
171 Posts
Discussion Starter · #1 ·
:) Hi guys , any help in this would be great . I have had a charge master box installed , it is a plug and play model ie no charge timer and I have a kangoo ze 33 which I believe doesn’t have a charge timer . So to get it charging off peak I need some sort of timer in line maybe to switch it on , any ideas anyone . Thus would be a huge help . I can’t find a mcb timer with 36a rating or any inline one
 

·
Registered
LEAF N-TEC 62KW
Joined
·
1,507 Posts
Looks like you will need to use a contactor activated by a timer.



Just to add that these links are an example, you'll need to check that you use suitable ones. (CEF list many timers from £15 to almost £200)
 

·
Registered
Joined
·
1,711 Posts
The safest way to do this is to fit a time switch that modifies the Control Pilot signal, as this is the official way in which timed charging should be controlled by the charge point. Switching the mains supply may cause all sorts of issues if done regularly, as the charger is not designed to be controlled like this, it should ideally be controlled to turn on and off gracefully by the charge point, using the control pilot signal.

This also has the advantage that it only involves working with a low voltage (+/- 12 V) signal, not mains. Some protocol controllers used in charge points have the built in ability to be controlled like this, some, like yours, don't.

The answer in your case is to break out the control pilot wire from the cable, should be easy, as it terminates in a connector inside the charge point. You also need to find the +12 V supply within the charge point. All told, four wires need to be extended to your timer control box, the control pilot from the cable, the control pilot from the board, the +12 V from the board and the 0 V or earth.

The timer needs to have a changeover switch, isolated from the mains side, like this one: 12-220V Time Switch Weekly DIN Rail Mounting Digital Programmable Timer THC15A | eBay

You also need a single pole changeover switch, to switch between timed and non-timed mode, plus a 1k ohm resistor to put the control pilot line to state A when the charge point is in the timed off state. I can draw up a simple diagram to show how to do this if it would help. My charge points are both timed like this, but use time switches controlling the protocol controller to ensure things are handled gracefully.
 

·
Registered
LEAF N-TEC 62KW
Joined
·
1,507 Posts
Yes, on reflection, a mains supply timer is a bad idea. Switching on is probably safe enough because there is a second or two whilst the car and charger communicate before the charging starts. But cutting the power to the charger whilst 32amps is flowing is IMHO not a good idea.

It could be done using a zero voltage / zero crossing (solid state) switch instead of a contactor since this will only interrupt the supply when the mains voltage is close to zero. A mechanical switch will arc so the potential for damaging spikes is high.

 

·
Registered
Joined
·
1,711 Posts
Far simpler and easier to just do it properly, by switching the control pilot. It's a doddle to do this, is a lot safer and doesn't involve repeatedly turning the charge point on and off at the supply
 

·
Registered
Joined
·
1,711 Posts
Here's a quick and dirty diagram showing how to add a timer to any charge point. If a +12 VDC supply can't be easily found to tap into within the charge point, then an alternative would be to use a low power +12 VDC power supply in the timer box. If a small DIN rail +12 V supply was chosen, then the 12 V version of the time switched linked to earlier could be used, as this would be "belt and braces" in terms of isolating the control pilot from mains.

The circuit works like this:

1. With the switch in the "ON" position the charge point works normally, and will charge immediately the car is plugged in.

2. With the switch in the "TIMED" position charging is controlled by the time switch set times.

To ensure compliance with IEC 61851, when in timed mode the control pilot is held at State A, +12 VDC, through a 1 k ohm source impedance. This commands the charger (in the car) to stay in standby mode, waiting for the availability of charge power to be advertised. Switching to State A also causes the charger to gracefully shut down on command, when the time switch turns off. When the time switch turns on, the control pilot is switched from State A to the charge point advertised power availability, and this then causes the charger to request power from the charge point, again gracefully and in accordance with the spec.

141932
 

·
Registered
Joined
·
214 Posts
Is it possible that the Kangoo could ignore any delayed changes to the CP. I wanted to implement delayed charging on my C-Zero and had a new charger installed. When configured to delay charge, the C-Zero ignored the instruction to start charging, my LEAF worked perfectly. In the end, I ended up using IP rated outdoor socket which has a wifi configurable timer included connected to the granny charger.

IMG_20210312_112408.jpg
 

·
Registered
Joined
·
1,711 Posts
The Tesla Model 3 used to do the same, ignore the change in the CP status if it had gone to sleep. This is a failure to comply with the requirements in IEC61851, though, so Renault should fix it, as it's a non-compliance issue. Tesla eventually got around to fixing the non-compliance problem with the Model 3, after they'd been pestered quite a lot about it.

Given that all smart charge points use the protocol within IEC61851 to control timed charging, by holding the CP in State A during the "standby to charge" condition, and as all new partly grant funded charge points have to be smart units, car manufacturers should really ensure that their vehicles are fully compliant.
 

·
Registered
Joined
·
4,706 Posts
AFAIK VW ID.3 has also had an issue with going to sleep when powered off, and then failing to wake up to charge when the CP line has been switched on again some hours later. A fault by VW, failing to follow the standard which in effect says the pausing state can be indefinite.
 

·
Registered
Joined
·
1,711 Posts
Sometimes it can depend on whether the charge point follows the protocol properly. I came across one that failed to properly go into State A when in standby, in that instead of holding the CP at a steady +12 V DC (through a 1k source resistance) it instead left the CP floating, which in practice meant that it was sat at about 0V. Some chargers may accept that (even though they shouldn't) but many won't, and will rightly assume that this means that the charging cable is not connected (the charger will assume that the charge point end of the cable may not be connected/plugged in, which is a valid condition for a non-tethered charge point.

I've also seen one DIY bodge where a time switch was just inserted in series with the CP, so again just leaving it floating when the switch wasn't on. As above, this works on some chargers that don't properly implement the protocol, but fails on chargers that do.

The key thing is that in the standby condition, State A in IEC61851 speak, the CP needs to be held at +12 VDC, and not left floating or have the 1 kHz advertisement pulse train running. All chargers should accept that if they are compliant, and should also wake up and then load the CP with the charge request switched resistance as soon as the 1 kHz advertisement appears, and as soon as the charger has set its own internal limit to not draw more current than is being advertised.

@Dan87 , I've just had a dig through my box of "may come in handy" stuff and have found the following parts to give a practical idea as to how an external time switch unit might look:

141950


The enclosure on the left is weatherproof (IP65) and the one on the right isn't, so would need to be fitted undercover. I think a switch with a weatherproof boot will fit OK in the flat area on the weatherproof box, or in the blanking plate on the other unit. All either would need would be a bit of two core cable to connect to the charge point, taking the CP line in and out of the timer box. The grey thing is a 12V power supply, so no need to poke around looking for a way to get +12 V out of the charge point itself. The box would need it's own mains supply, with the same earth configuration as the charge point (so if the charge point has an earth electrode the box also needs to use that connection).

Might give an idea as to how something like this could go together fairly easily. At a rough guess, the bits above (inc. one of the enclosures) probably add up to around £40 or so.
 

·
Registered
Joined
·
171 Posts
Discussion Starter · #12 ·
Thanks everyone for your replies . Really appreciate it . I suppose there no telling unless I try .
 

·
Registered
Joined
·
171 Posts
Discussion Starter · #13 ·
Really informative stuff . I may get a electrician to do this for me . I’m just a humble carpenter
 

·
Registered
Joined
·
1,711 Posts
@Dan87

Just found a photo that another member here, @Todor , has posted, showing exactly where the internal connections need to be made to add a time switch. This is the photo that was posted in another thread:



I've cropped that image down to show the connector that has both a +12V supply available and also the Control Pilot connection:

141984


To connect a time switch box, as per the diagram given earlier, looks dead easy. There's a +12V supply available at the lowest terminal on the black connector block, the earth is available on the screw adjacent to it and the red wire is the Control Pilot from the tethered cable.

All that's needed is to disconnect the Control Pilot and extend that wire out to the time switch box, add the new CP wire from the time switch box to the place where the old red CP wire was connected, add a wire to take +12V to the time switch box to the lowest terminal on the black connector and add an earth wire to the ones already using that screw.
Should be possible to drill a hole in the case somewhere convenient, fit a sealing cable gland to it and run a length of multicore cable to the time switch box. If it were me, then I would probably also tap into the incoming mains supply wires in that box, just fit some 41A rated Wago 221-613 connector blocks to tap off a supply for the time switch. A run of outdoor rated 5 core flex could then just go to the time switch box, making for a neat installation, with no additional wiring needed.
 
1 - 14 of 14 Posts
Top