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RCBO Energy Consumption/Losses

statter
Just refitted a large consumer unit with Wylex miniature RCBOs.  Looks like a decent compact product.  When energised on no load the metal CU casing ran about 5 degrees C above immediate surrounding ambient (in a very large cupboard).  Wylex spec says full load losses are 1.5 to 2.6W per pole and these are two pole devices.  I think this would break down between no load loss and a loss that varied with current (along the lines of copper and iron losses with a t/f).

Given the temperature rise I observed (which so far as I can tell with my cheap IR thermometer) is uniform across 20 devices the standing no loss dissipation is likely around 0.5W plus each.  Whilst this will keep consumer units warm it will also add to bills.  A 20 device CU with 0.5W per device will use 87kWh costing about £13 pa.  

I haven't got the kit to measure the losses accurately but this is certainly something to think about when specifying larger installations.

Looking across other manufacturers I see Hager quoting 3W for a single pole RCBO at full load so the Wylex unit does well by comparison.

Has anyone measured the standing losses on these and other 'electronic' devices? 

I expect we will see a new section in the Regs on losses before long given the increasing focus on energy efficiency.
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    You have to fire triac to pull in the the actuator coil, which is several mA, a  simple shunt regulator,  like a dropper  and Zener diode combination  needs to pull this all the time, so that it is ready when required you'd need a series reg or a switcher to allow you to draw less current on standby - as I said earlier a custom chip could do this,  with a high voltage pass transistor process.  You could even integrate the firing SCR onto the same die - ideally a biCMOS process that allows transistors and both polarities of FETs, but that would give you a higher ultimate cost per chip. (MOS only or bipolar only are cheaper as there are less foundry steps.)
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    You have to fire triac to pull in the the actuator coil, which is several mA, a  simple shunt regulator,  like a dropper  and Zener diode combination  needs to pull this all the time, so that it is ready when required you'd need a series reg or a switcher to allow you to draw less current on standby - as I said earlier a custom chip could do this,  with a high voltage pass transistor process.  You could even integrate the firing SCR onto the same die - ideally a biCMOS process that allows transistors and both polarities of FETs, but that would give you a higher ultimate cost per chip. (MOS only or bipolar only are cheaper as there are less foundry steps.)
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