Can I run equipment desighned to run on 230 volt 3ph on 208 volt 3ph without harm?

Yes you can, but be very careful. What's going to happen is that the equipment isn't going to necessarily need all the power it says it requires on the label unless it's used to its maximum potential. In the case that you are putting it to a lot of use, what's going to happen is that it's going to put the pressure on whatever it is that's providing energy, and it's life expectancy is going to rapidly decrease.

If what you're doing is charging a cell phone, then don't worry at all. The difference is insignificant, but I strongly recommend that when you're not using it, to disconnect it from it's power supply. You're also going to notice that the power supply is going to be very hot, and that's because it's working harder than it's supposed to, which again, can potentially ruin it.