32a breaker to a 40a breaker

[myksterx]

Hi, this is my second post here please do not bite. I had fantastic responses from previous post that put me right and everything has been fantastic since. Thank you again. 
 

i have a 2.5mm ring on a 32a breaker going into my shed and into my man cave (both joined onto each other)

had no issues at all. 
 

until recently i have added a brand new wall mounted air conditioning unit, which was installed professionally mind. 
 

it all works well and good, but since installing this unit, my electric trips on the 32a breaker every other day, even though the air conditioning unit is continuously in use. 
 

i have had the installer out. He has tested all his work, all wires, tested the actual unit. Which is brand new. All is well there. 
 

i done a test and turned the aircon off for 7 days. No random tripping. 
 

then i done a test and kept aircon on for 2 days, random trip. 
 

then again a few hours after with aircon on. 
 

i then switched the aircon off and again, trips stopped. 
 

its 100% the amount of power being dragged through on this ring and its the aircon unit sending it slightly over the edge. 
 

my question is. 
 

can i safely add a slightly bigger amp fuse?

i am currently on a 32a fuse. 
 

what would be the next jump?

40a? Or less?

would that be safe on the actual 2.5mm ring

 

[Andy™]

a ring is designed for 32a max. it will not be safe on a 40a

if you need more capacity then you will need to install another circuit to share the load

 

[ProDave]

What the professional installer should have done, is installed a dedicated circuit of the correct rating to run the aircon unit, not put it on the socket circuit.

 

[Murdoch]

If you have a random trip caused by the AirCon unit that’s what you need to fix.

 What power supply does the unit need?

 

[Geoff1946]

You seem to be using a heck of a lot of power to regularly overload the ring.

Even if the air con is taking 3kW (Unlikely I would think) that's still another 3 or 4kW going elsewhere. Do your appliances add up to so much?

Does it trip on the start up surge of the air-con compressor?

 

[Sidney]

I'm thinking this is a current inrush on start up doing this. Ideally the AC unit needs to be on its own dedicated circuit.

Just chucking 40 amps in will not do anything apart from make your circuit unsafe.

Do you have the specification for the AC unit? I'm guessing it might require a C curve.

 

[Evans Electric]

Do you have the specification for the AC unit? I'm guessing it might require a C curve

I thought that too  .     I presume you are tripping an MCB   NOT  an RCD   so as said above ...hell of a lot of current  being used on ring  to be tripping on overload .    

Don't fit a larger MCB  .   

 

[SPECIAL LOCATION]

The MCB's  ( aka fuses / breakers ) are there to protect the cable.....

Laws of physics..

Electricity ALWAYS generates heat whilst travelling along a cable...

More power = More current = More heat...

The cables in the circuit MUST be capable of carrying the maximum current that the MCB/Fuse/Breaker will allow to flow..

i.e.  in the event of a fault the weakest link MUST NOT be the cable!!!

otherwise cables will overheat / melt / start fire / be significantly damaged...

If an MCB is tripping 99.9999% of the time they are doing their job correctly...

and the solution is to correctly identify and resolve the problem....  

Changing the fuse rating is not normally the correct solution..

Unless you have proved 100% that the cable is capable of carrying any new current ratings that a different MCB/Fuse/Breaker will allow to flow..

An "incorrect fix" may make something appear to work...  "for a while"...

But a few hours...   days...  weeks or months later the true implications of incorrect protection on a circuit may become a very expensive solution!

Electrical circuits must be designed to "Fail Safe" ...  Not just work!!!

I doubt I would be looking at increasing the rating above 32A

Guinness