Why doesn't my compressor shut off when it reaches it's max psi This is a industrial 5hp Ingersol Rand 240v 3phase typehow do i adjust the dump switch?

The likely problem is the setting of your pressure switch. These models differ and you'll likely have to locate the manual for your switch. The manufacturer and model will usually be listed on the pressure switch case. The dump valve will likely do nothing except cause the air to be released in case of overpressure. It won't cause the compressor to shut off when it should.