Greetings Experts.

If we send 230Vrms out of a product to power an external device through an IEC 
Outlet connector and we need to provide Overcurrent Protection for this port 
internal to our device, can I use two fuses or do I have to use a double pole 
circuit breaker?

Since our product can be used in a 220-230 Vrms power system which cannot 
guarantee polarity on the plug (such as Europe) or that the neutral will be 
grounded (some North American power systems for example), we have to have 
over-current protection on BOTH sides of the line (all current carrying 
conductors).

But when we supply power externally to another device, it is possible that one 
fuse could open and the other side of the line is HOT to Earth. Someone working 
on the external device could put a meter across the line as see there is no 
voltage and assume the AC mains is OFF not knowing that one side of the line it 
still HOT to Earth. This could cause a hazardous condition.

SO, this is the reason for my question. If our device supplies power externally 
to another device, can we use fuses which could cause the hazardous condition I 
explained above, OR must we use a Double Pole Circuit Breaker which opens all 
HOT conductors simultaneously? If I must use a breaker, what standard or rule 
dictates this requirement?

OR is this even a scenario we have to be concerned about?  Since the external 
device has a warning label to disconnect power cord before servicing, is this 
even something to be concerned about?

BTW, my product is Laboratory Equipment (UL/IEC 61010-1) to sell on a worldwide 
market.

Thanks,
The Other Brian
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