The relay is rated at 16A, and although it has overload protection, this is electronic and if the contact welds, the overload would not be broken by the relay itself.

The regs get a bit messy with this sort of thing, as there are a lot of different characteristics to consider. Roughly speaking overload and fault current protection may be treated separately, with with the possibility of overload protection being downstream (or even implicit in the nature of the load), so often it's the fault current characteristics that need to be considered - which are often rather different to the simple long duration current rating of an item. It's the kind of consideration that lets us use what's basically 20A cable for an unfused spur from a 32A ring circuit.

In the old days we'd sort of consider a 16A accessory as being roughly equivalent to a 16A conductor and calculate on that basis but that always was a bit of a kludge especially where the device is capable of making onto a fault or attempting to break a fault current - these days there's an entire section (536) demanding we consider all sorts of characteristics, but I think in most cases it boils down to 'ask the manufacturer' - either for stacks of data or just for their requirements for upstream protective devices for fault protection.

   - Andy.

The relay is rated at 16A, and although it has overload protection, this is electronic and if the contact welds, the overload would not be broken by the relay itself.

The regs get a bit messy with this sort of thing, as there are a lot of different characteristics to consider. Roughly speaking overload and fault current protection may be treated separately, with with the possibility of overload protection being downstream (or even implicit in the nature of the load), so often it's the fault current characteristics that need to be considered - which are often rather different to the simple long duration current rating of an item. It's the kind of consideration that lets us use what's basically 20A cable for an unfused spur from a 32A ring circuit.

In the old days we'd sort of consider a 16A accessory as being roughly equivalent to a 16A conductor and calculate on that basis but that always was a bit of a kludge especially where the device is capable of making onto a fault or attempting to break a fault current - these days there's an entire section (536) demanding we consider all sorts of characteristics, but I think in most cases it boils down to 'ask the manufacturer' - either for stacks of data or just for their requirements for upstream protective devices for fault protection.

   - Andy.