Tax Question on a Cash Out Refinance

One of my clients in Arizona is considering do a Cash Out Refinance on a 4-Plex (Investment Property). The client plans to use the funds from the cash out refinance to pay off his personal residence.

Will this scenario create any tax issues for my client?  

I was concerned that he would be converting funds from his investment property to personal and it could trigger a tax event on the converted funds.

Thanks for any thoughts any of you have!!!