"Smart" Consumer Unit

[wildebus]

I was looking at SquirrelCooks Consumer Unit and thought it very neat.

I decided to build a little variation combining a couple of products I do as well as employing a kind of principle I try to have with my products to make them simple to install.

So this is my Smart Consumer Unit with its IP65 Housing, so good for a Camper Installation

Under that cover you have a RCBO for the incoming AC, and 4 MCBs - 16A, 6A, and then a 10A and another 6A. - but a gap in the middle?

Well, there is a reason for this And what makes it a Smart CU

The two MCBs on the left are dedicated to on-EHU only.

• The 16A is the high-current supply so would be used for say a Room Heater, or similar things that you would only want to use on hookup.
• The 6A is for a Mains Battery Charger

The two MCBs on the right are auto-switched between EHU and Inverter and for general purpose AC devices you might want to be able to use off-grid

• Two circuits available - 10A and 6A

If you don't have an inverter, the two right hand MCBs act exactly the same as the two left hand ones, so is designed to be upgrade-ready for a Inverter installation with automatic socket-sharing.
Addtionally, when used with the Inverter, those circuits can be controlled with a device such as a Victron BMV and programmed to shut off if the battery State of Charge drops below a selected value.


And the Easy to Install part ... the entire Consumer Unit is fully pre-wired
The EHU Input is via a flying lead with a 20A Quick-Connect Plug.
The Inverter input is via an integrated IEC plug on the opposite side, allowing for inverters up to 2400W to be used.
The relay control signal is via a simple jackplug connection.
The MCB outlets are pre-cabled with Tyco Mate N Lock sockets and are also colour coded - White for EHU and Black for EHU/Inverter.

Photo of the naked unit with the leads is below. The only time the installer/user will have to take the cover off is when they want to attach it to the wall with some screws (I would have used VHB tape to avoid that if I could be sure of the surface it would be attached).

Only problem is not actually got a use for it Ah well

 

[trevskoda]

Looks good, one thing i think to add is a input phase changer before the box.

 

[wildebus]

I did think of that kind of thing but thought better as a separate thing.
Adding an "active" and "wrong polarity" light might be worth having though

 

[SquirrellCook]

Idiot lamps are always good.

 

[Sprinter 1 cup]

Can you make one for DC ? Is that a 4x6 as size matters. Lol. I wouldn't mind a all in one unit in my van !.

 

[wildebus]

Can you make one for DC ? Is that a 4x6 as size matters. Lol. I wouldn't mind a all in one unit in my van !.

I've been trying to find an affordable Box that neatly combines AC breakers and DC Fuses together (so like you would see in say a Sargent Housing for example) but the DC bit is the tricky part.

That Smart CU box would be 18mm (width of a single breaker) x 8 (breaker positions) plus a bit more for the surround. Not measured but would guess around 7" x 7"
The height tend to be the same - width down to how many breaker positions there are potentially.

 

[Deleted member 12559]

I didn't think they still made the RYD changeover switch Trev. Mine has been fitted 27 years, useful
in Euroland and beyond, due to 2 pole live hazard when used with single pole UK equipment.
Especially when they looked like the deluxe model below !

 

[trevskoda]

I didn't think they still made the RYD changeover switch Trev. Mine has been fitted 27 years, useful
in Euroland and beyond, due to 2 pole live hazard when used with single pole UK equipment.
Especially when they looked like the deluxe model below !


View attachment 4528

View attachment 4525

Handy, think the charger/battery boiler is from the stone age, try a numax or other smart chargers.

 

[Deleted member 12559]

Agreed Trev. certainly from the stone age, but there's a rhyme to the reason. When I fitted that Zig unit,
95% of the time I stayed in campsites on hookup. Rather than boil the batts. the charger only
topped out at 13.8V. max. then reverted to float trickle charge. Invariably I'd move on after a few
days and the alternator would give them a bit extra, not perfect, but still the Halfords starter batts.
used for the leisure side, lasted 10 years. Simple but worked. The 12v to 24v changeover system
is another story !
Then campsites overseas started getting too crowded for my liking, decided to become a
FLT so fitted solar panels (21 years ago) the Zig became mostly redundant, what with LED lights,
LED TV. water pump, heater fans, etc my 12v demands were quite low, the van virtually only gets used
in southern Europe, rare for the batteries not to get enough charge, & even if they don't I wouldn't
frequent a campsite, the B2B and a drive to the supermarket usually tides me over.
I should state that I rely for serious energy, ie heating, cooking, washing on gas, and with Spanish
gas being relatively cheap £12 for 13kg. there's no imperative to upgrade the electrical equipment
for the forseeable.

 

[wildebus]

Continuing on from the Smart CU, I have built a couple of new boxes, designed for when you have a supply which is already fed by Inverter and EHU (either because you have already fitted a Transfer Switch or you have something like a Victron Multiplus installed) but you want to be able to control them further.
I do already have this functionality added in my own Motorhome but needed to build the same same setup in "pluggable" boxes that eliminate having to do anything more on the AC side than fit a plug or socket.

So we have a Fridge Controller - the WAC-100 .... AC In, AC Out and a control input that you can connect to a programmable relay like on a Victron BMV Monitor, or even just a simple switch to enable or disable the AC supply

Called it a 'Fridge Controller' but you can use it for any purpose really, although I would use this one for lower or intermittant power devices, such as a Fridge. (The next controller is for the higher power devices).
I use this setup on my AC Fridge and I can remotely (via the Internet) turn the normal Domestic 240V Fridge on and off as I need to. More regular use might be to connect up a Victron BMV Monitor and enable the AC to a 3-Way Fridge with Auto-Energy Selection and have the fridge switch to AC when the batteries are in a high enough state of charge (and maybe supported by a good Solar Array).
This particular unit will be connected precisely in that mode, plugging into a Thetford Fridge in a Hymer.

The 2nd Controller is basically the same but with a couple of extra features... The WAC-150-CT ...

AC in & Out again, with a control input again to turn on an off, but the WAC-150 is designed to work with constant higher loads due to increased Passive Cooling (aka Heatsink). This makes for a physically larger unit which may not be suitable for all locations, which is why the WAC-100 is great for those low-power things like fridges.
The other feature is the "-CT" bit - the Countdown Timer feature. You have the control input as before, but you also have a presettable timer that you can use to override the control input, but only for the set time, after which the timer turns itself off and you have to turn the switch off and on again to have another timed period.

This particular example is again going to be fitted into a Hymer, this time on the Truma Combi, with the Main control connected this time to a Cerbo GX configured in a specfic way, and the Timer Control just going to a switch that the owner will turn on to have the Truma come on for a hour for water heating (the 10L water tank in a Truma takes around 55 minutes typically to go from cold to fully hot)

Again, I have added this functionality into my Autotrail so I have the Water Boiler AC available as long as the Battery SOC is high enough or there is EHU present, but if either of those two conditions are not present, I can still override with the timer for 60 minutes if say I know I will soon be driving so recharging the battery, or it is a good weather forecast say and good Solar charging is expected.

These boxes would usually be supplied with IEC13 connectors to allow them to be easily plugged in, but in the case of these two units it will be different ... you might have noticed the connectors on the WAC-150-CT? These are Wago 770 connectors to take advantage of a very handy feature on the Hymers ...
Hymer use this style of connector on the AC connections in their Motorhomes. It makes it very quick and easy when building to just plug in the various devices, and great for servicing as well. But it also means it is very simple to add in a box in line. For example, here is the back of a Thetford Fridge in a new Hymer ....

Behind the gas pipe there is a white connector going into a black connector? The White is the AC Supply Socket and the Black is the AC Fridge Plug. To fit the WAC-100, it will simply be a matter of separating that existing connection, and plugging the two connectors into the corresponding plug and socket on the add-on device and that is the AC rewiring done
Then just a twin-core cable run to the BMV or switch and jobs done

 

[trevskoda]

Slow down wildbus or you will blow a fuse for sure.