Isolated Power System in Operation Rooms

It depends on the critical nature of the application....If it is fail-safe design you have a redundant system backup....

Do you wish to design a safety protocol to follow in this case ?

One of the primary functions would be to remove the patient immediately or ASAP.

Hopefully there is more than one OR and it has a separate XFMR because

another primary function would be to CLOSE the OR until the fault is repaired.

Safety of patient and staff first; repair second.

If the transformer fails then you have no power.

What are the chances the transformer will fail compared to how critical keeping the power on is. You need to do an analysis and if necessary say add an automatic transfer switch or some other means of keeping the power on or getting it back on quickly. This could be as simple as having a spare transformer handy.

I took it as the transformer is being used as an isolation transformer, and the operation room is actually a site control room.

Your guess is as good as mine until more information is offered!

They have earth monitoring system too.

Assuming it's a medical operatory the consequence is no worse than the failure to operate of any piece of electrically powered medical equipment. Everyone in that room is trained to respond quickly and either move the equipment or move the patient, and continue the procedure.

Surprisingly OP considered only one failure mode, fail to provide power, when the more life threatening situation is loss of isolation between patient circuits and power/grounding circuits; that situation could prove to be instantly deadly.

The only reason why an isolation transformer were installed in the O.R. is to ensure that patient were safe from all electrically operated devices. Safe from High leakage current problem generated by every medical equipment used and connected to the patient in the olden days. Minimizing patient's exposure to what is known as micro shock hazards that normally can trigger heart fibrillations.

In the early 90's isolation transformers are no longer a requirement due to changes on modern equipment designs which solved majority of these electric shock hazards. Changes which in turn trigger the corresponding changes or revisions in the applicable codified NFPA 70 standards. Presently all hospitals / healthcare providers are standardized to use "Hospital Grade" U-gnd outlets on all critical or not areas of such facilities.

Although not applicable to you're location BS7671 corrigendum 2 section 710 is dedicated to medical locations.

It's well worth a read.

This old scenario existed in the 70's - 80's, where operating suites in the hospital are designed to use isolated power supplies. This was necessary to enhance patient safety in the O.R. During those days when situations like this occurs and utility power were interrupted for whatever reasons, the on-going operation procedure is not and cannot be interrupted even to the point of just using flashlights to light the surgical site.

If the medical procedure requires high powered, advanced medical instrumentation, ie., (open heart bypass or transplant), another room will be prepared for case transfer, but the ongoing procedure continues until completed!

The technicians will just have to wait until that room is vacated or until the clinical procedure is completed!

Isolated power supplies in operating rooms are no longer necessary nor required since the year 2000 in the states.

Many of the modern OR equipment in use today has internal battery backup systems. A well known unit similar to these is the blood pressure monitor used for patients in rooms. Usually the more critical the unit the better the back-up. Other alternatives, especially for ability to see are battery powered back-up lights (similar to emergency lighting), flashlights, larger fire fighters hand lights, and various other methods. some OR's have back-up generators solely supplying them.

During/after Hurricane Sandy many hospitals declared states of emergency so they could readily obtain generators, over several thousands of them. Since no or very little preplanning had been done they were located near the end-user. This then created another problem- Carbon Monoxide levels in excess of the permitted levels in the vicinity of a high generator concentration. Some unique temporary solutions were used but mostly relocation was used.

Good Luck, Old Salt