Hummmm that sounds like a fire just waiting to happen. if you are running 3 miners and dont want a fire you really should have separate outlets all with there own breakers or fuse.

     and you dont want to go putting in a higher amp breaker if you dont have wiring meant to run a heavier load. Or else if you overdraw on the circuit its going to not cause a bigger breaker to trip and will instead start melting wires inside your walls or at the outlet its self and thats when fires happen.

if you are on 220v each miner will draw about 6amps.  So you could get away with 3 miners running on one 20amp breaker or fuse. Tho If It were me Id have no more then 2 s9's on each circuit with no higher then a 15 amp breaker/ fuse.   and if you keep popping a breaker or blowing a fuse it would mean you have a problem some were thats causing the circuit to overload.   The one thing you don't want to do is keep throwing in a higher amp breaker or fuse if it keeps poping them.   Cause thats defeating the whole purpose of a fuse or breaker in the first place.  Id also never use an electrician again that did not know that you don't just go through a bigger fuse in a circuit that cant handle a higher amp load. 

Even if it costs a few more days of mining to pay for a property safe wiring set up to run your miners.  its worth it in the long run cause if you end up burning down the mine that's a lot more mining lost and peace of mind is also got to have a value as well.