24v transformer to fit Hager CU

[Ragnar_AT]

The UK is the only country I‘m aware of that type tests DIN rail CUs together with the MCBs, bus bars, etc.. Everywhere else in Europe the enclosure and contents are separate. Only the devices and bus bars need to be compatible. I was once sold Eaton MCBs and RCDs together with a Hager enclosure while a Hager sales guy stood next to me at the counter joking if you could even do that without causing an immune reaction (that was at an Austrian wholesalers).

 

[ericmark]

Three points, one some CU used half a din rail, and it needs the unit to also connect to a bus bar. The hole in the lid does not match all makes. And the position of the bus bar to the DIN rail is not to a standard. With half DIN rail, a third party transformer is a non-starter, with the bus bar location this hardly matters with a transformer as it does not connect to bus bar, so it is down to where the hole in lid is to if the transformer will fit.

If it will physically fit, the next question is heat. With an industrial unit, one can find a board handling 100 amps for an extended time, and heat is a big factor. But with domestic, traditionally we would only draw high amps for a short time, so heat in the board was not a problem, the longest and highest use was likely the immersion heater, even with storage heaters they had their own dedicated CU.

Today however things have changed, we see storage batteries, EVs, and heat pumps, resulting in quite high prolonged use of circuits and the associated MCB/RCBO. My own house note, the graph goes down as the use goes up, shows 5–7 kW used for an extended time overnight, at a time when I am unlikely to go anywhere near the CU so would be completely unaware of any over heating problems.

I have an off-peak rate which is far cheaper than the peak rate, so I set dishwasher, washing machine, tumble drier, and battery charging to when the off-peak supply is available. The rest of the day, I hardly use a kWh of electric. When we talk about fitting what is likely a switched mode power supply, so something filled with electronics in what may be quite a warm enclosure at some times of the day, we need to either rely on the manufacturer working out if there is a problem or not, or we work out if there is a problem or not, and also we need to consider changes in use in the future.

I for example know, I could not plug in a balcony solar panel without first changing my RCBOs, but most users would not even think there could be a problem. With MCB's there would not have been a problem. And we remote from the home in question have no idea as to if there would be a problem or not.