Help! Power question

You may need to balance the load. On the panel should be 2 legs. Put ac on one side and outlet on the opposite leg.

pcc67

On the panel should be 2 legs. Put ac on one side and outlet on the opposite leg.

His problem is with a central A/C. That means it's almost certainly 240VAC (if in the US), which means it's attached to both legs of his electric service.

Let me be clearer on the subject of balancing. On the main breaker 200amp  you have 2 legs off that, that go down the center of the panel. The breakers on the left are one one leg. The breakers on the right are on the other leg. If both the ac breaker and the breaker feeding the outlet you are having issues with are on the same leg, this may be the issue with the drop in power. You are drawing current off the same leg. Balancing would put both circuits on opposite legs. Also you may need a starter kit. I also have central ac. But my HT room is on separate leg. No issues.

pcc67

On the main breaker 200amp you have 2 legs off that ...  If both the ac breaker and the breaker feeding the outlet you are having issues with are on the same leg, this may be the issue with the drop in power. You are drawing current off the same leg. Balancing would put both circuits on opposite legs ... I also have central ac ... No issues.

In the US, most central A/C units are 240VAC. That means it would be connected to both legs of the electric service.

Cleeds, 
At the main breaker the load is split, 2 separate bus bars each caring 120 volts. When you add a 30 amp double pole breaker you have 2 hots coming out, each hot out is 120. 30 amp double pole is like using two 15 amp singles, each single is 120. When add together that equals 240.  You dont need to be on 2 separate bars to get this. the double pole breaker is on one bus bar using 2 spaces.  I live in the US.  Electrical is a hobby of mine for 25 yrs.  I've have run electric for 2 ac in the past 2 yrs.  I believe his wiring is correct or he would be popping the breaker. I believe the load is very heavy on one bus bar, which is fine. But he can balance it by putting the problem circuit on the opposite bus bar. When ac kicks on, the load will pull from opposite bus bar. Both circuits pulling loads from 2 separate legs. 240 come in at top of panel and splits, 120 each side. If this is new compressor it should have soft start built in. If not have a starter kit installed,  but I would go first solution, balance. Good luck Pete