I set up a separate circuit for a computer in an apartment with 40A service. When the compressor goes on on a 5000 BTU window air conditioner on a separate circuit, the computer screen jiggles a little. While the effect on the monitor is bad enough, it is logical to assume the computer CPU etc. is seeing the same interference which may be an even worse problem.

Is this normal? Is there anything that can be done to prevent it. The computer and peripherals are plugged into a surge suppressor/ battery back-up.
--TomBrooklyn

This would not normally be unusual, but I would not expect it on a system with a UPS.
Don(resqcapt19)

How close is the AC to the monitor? Monitor distortion can be caused by a strong magnetic field which leads to the second question. Is all the grounding, all the way back to & including the service done correctly? Grounding mistakes can lead to magnetic fields that would be capable of causing monitor problems.

Good luck