Ahh, but they do exist…3pole earth leakages with no neutral.
Then where will one use such a thing?
But it gets worse:-
Why would ‘Hager have a 3pole earth leakage device BD364, BF364, BDC364, BTC364 – I can’t use these for motors and the like, they will trip for nothing, or will they?
So where will you use them?
Motor protection is one – but be careful, there are numerous elements that can cause “normal” residual / imbalance currents between phases – these might seem like earthleakage currents to the units.
One is voltage differences between phases – I read somewhere 1% voltage deviation causes 6% current unbalance.
Also a motor is a pretty dynamic load being inductive and having that type of starting characteristics..because these RCD devices are not flexible – having no real adjustments it could prove a challenge. Rather use a proper electronic based motor protection unit.
Other places one can use the 3pole devices is with elements.
But yet again, smaller element like kettles sizes might not be an issue so one can use them with ease…issue is the larger ones. The larger ones inherently has a unbalanced/leakage currents – it is for this reason one an find an electronic earthleakage up to 30A sensitivity.
Note to self: Do a presentation of the benifits of a good qualty motor protection device.
Note to self: Present the different classes/types of earth leakage protection deices.
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