I am going to briefly explain where did I purchase my five Aube’s Relay/Transformer RC840T .
in a previous post, I had mentioned the following:
#1 this product is not available in France and possibly not in Europe as it is not EC “stamped”
#2 Aube (North America) did categorically refuse to sell me a few units – probably for liabilities/warranties reasons.
I just want to make it clear I am not affiliated to Smarthome, but it turned out this is where I have placed my order for five units.
honestly, this turned out to be a smooth process (I even talked to their hotline at first), however it is worth pointing out that shipping costs were high – that’s also the reason why
I did order five units instead of one as originally planned.
The RC840T acquired is located here. I am under the impression those items are currently on sale as I post this message (!)
and I have recently posted feedback and rating which one should be able to read once they approve it.
for those of you interested, I am happy to share details of both shipping and taxes. I will post later…
- default wiring for high voltage thermostat
to all, above is a drawing of my previous configuration using a “2-wire” thermostat, high voltage that is 220 240 Volts, directly connected to my gas heater.
couple of key points:
#1 the thermostat had batteries internally used to trigger the “dry switch” (now on the drawing).
#2 upon “heat” command (ambiant temperature below target) the “dry switch” basically closes the electrical path between Ls and Lr
#3 once Ls and Lr are connected together, this triggers the heater (gas + circulator)
#4 Ns connector is shown although not used in this configuration since thermostat operates from its own supply (internal batteries)
- nest thermostat 220v europe
following request for clarification,
here is my understanding of how this works, and particularly what is the RC840-240T doing for you.
#1 RC840T-240T is overkill – this box is designed to drive directly an electric heater (2kW or so…). this means the relay in this box can carry a lot of current
#2 note this device is not approved in Europe, probably because of 50Hz and 220 240 Volts (versus 60Hz and 110 Volts), so a new certification would be required.
#3 and I Will pause here, I have a doubt about the need (or not) for the C wire to be connected honestly, so I will investigate and report back once I have a chance to spend more time.
my heater is a basic elm leblanc acleis 23kw natural gas.
it works on 220 240 volts and is currently trigger by a 2-wire high voltage thermostat.
here is the front of the heater
with the cover removed
the Aube/ RC840 box will connect instead of the grey and black wires.
those are precisely hooked to Ls and Lr connectors.
it is worth noting that I will leverage from the Ns connector which on a high voltage 2 wire thermostat is not used.
I had initially the “ambition” to build my own transformer/relay in a box…
it turns out that both work and family activities forced me to look for a plug & play system.
I have ordered 5 units of this Aube RC840-240. Note those aren’t certified to operate in Europe… so you cannot supposedly buy them in Europe (have discussed with Aube themselves via emails and they refused selling me those).
So, I ended up buying those units from a 3rd party shop in California, they have arrived this last week end.
yesterday evening, at least to verify the concept would work, I plugged my current 2-wire “high voltage” thermostat thru this RC840-240 unit… and it works great. Picture and block diagram to come soon.
essentially, I am one step away from having my Nest wired to my heater a ELM Leblanc (natural gas) unit. Note the system I have actually selected could work as well on Electric heater systems with some cautious calculation.