The subject of ungrounded electrical systems can get a little complicated, but let's see where this leads. I can't imagine why y'all need to do this, but I reckon it can be done.
First let me clarify something, that the conduit / enclusure / equipment grounding will remain firmly in place. I presume you intend to simply remove the neutral-to-ground bonding, leaving all the touchable metalic surfaces grounded, for obvious safety reasons.
When I was stationed on a submarine back in my Navy days, we had ungrounded 3-phase 450VAC & 120VAC systems for general power & lighting requirements, operating from delta transformers. Equipment enclosures were still "grounded" to the ship's hull for safety, but the electrical systems were not grounded at any point. This was for tactical reliability: the electrical system could become inadvertantly grounded at any one single point in the system with no effect on the operation of the system or the equipment. We were very aware that a second inadvertant ground at a different point would result in a short circuit. For that reason, we had permenant ground detection circuitry that monitored the systems, and any significant drop in insulation resistance was detected and corrected immediately.
As I understand things, there are a couple of reasons why land based electrical systems are grounded:
1. Provides a cap or limit on the max voltage to ground for your electrical system, and
2. Provides a low impedance ground path so any ground fault that might occur will draw a large enough current to ensure quick clearing by the upstream fuse or circuit breaker.
You naturally would loose these benefits if you ungrounded your system. Is that what you really want? Another option might be to check the possibility of setting up a hi-impedance ground. I'm sure there are others here more familiar with them than I am.
Good luck,
Radar
