Electrical main breaker problem

[WilliamCave]

We renovated a small shop house with 5 rooms many plugs and lights etc

Every thing was installed new even the breaker panel , the A/C s have there own breaker panel also ,

The kitchen has all the standard appliances , fridge , coffee pot , toaster etc

The office has 3 printers 3computers phones etc

Now the problem is the Main breaker trips when we try to turn on a few things in the kitchen and it is getting worse,

Went to the office yesterday and the main breaker was triped again and we weren't there and the only thing on was the fridge .

My wife talked to a power company about it and they looked at the meter and said it was to small for the 2A/C and equipment we have in the office and 5 rooms.

And the wire going to the breaker box was not sufficient ,

My question is could this cause the main breaker to trip because to much power draw on the line and small meter ??

[petercool]

Moved to Electrical Forum

[trogers]

Is your electric meter 5amp or 15amp? The former cannot support air-conditioning.

[Crossy]

Is the front end breaker an RCD (has a 'Test' button)? If so you have a classic neutral-earth fault.

Current rating (Amps)?

[WilliamCave]

The A/C s have there own breaker panel it is new

We also have a new breaker panel for every thing else

[Crossy]

Do you have an RCD (has a test button)?

Is it this breaker that is opening?

What meter do you have? (5/15, 15/45, 30/100)?

What is the current rating (Amps) of the main incoming breaker?

EDIT Since you have new stuff, has the system ever worked properly?

EDIT 2 A few photos of the distribution boards would be handy, with the covers off if you feel confident (power off).

Do you have a multimeter?