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Thread: Hospital Operating Rooms Power Supply

  1. #1
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    Hospital Operating Rooms Power Supply

    Are Hospital operating room required to have isolation transformers on their power supply if no flammable anesthetics are used.

  2. #2
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    Re: Hospital Operating Rooms Power Supply

    Preventing ignition of gases, is not the purpose for isolated transformers.

    Any where electronic monitoring equipment is used, the equipment is required to be on isolated power.

    Believe it or not, the little cotton swab with cleaning solution, used to clean the skin is the cause for isolated power.

  3. #3
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    Re: Hospital Operating Rooms Power Supply

    The NEC doesn't require Isolated Power Sources anywhere in hospitals.

    See 517.19(E)

    Roger

    [ June 19, 2003, 06:22 PM: Message edited by: roger ]
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  4. #4
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    Re: Hospital Operating Rooms Power Supply

    I agree Roger. The NEC does not require an isolated system, except when the diagnostic equipment is listed for an isolated power source.

    Most medical diagnostic equipment such a EKG and EEG instruments that make contact with the human body require an isolated power supply. This power source must be external, to be effective.

  5. #5
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    Re: Hospital Operating Rooms Power Supply

    Bennie, you know you and I agree on "Isolation Power Sources" and the safety it could provide in everyday uses (non hospital) if we could get the monitoring and safety valves fine tuned.

    Roger

    [ June 19, 2003, 08:50 PM: Message edited by: roger ]
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  6. #6
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    Re: Hospital Operating Rooms Power Supply

    Roger: Prior to 1914, apparently domestic power was not grounded. There was very good reasons for opposing the present grounding concept.
    European systems are 230 volts to ground, so the excuse that 120 volts is safer has not proven to be true. The ability of 230 volts to clear faults makes it safer than the 120 systems. Statistics support this conclusion.

    Monitoring an ungrounded supply is not entirely necessary. Should one line go to ground accidently, the system is like the one we now have. Knowing this fact is necessary to inform the user, about losing one level of protection from a shock.
    The fault would have to be cleared to provide the two levels of an ungrounded system.

    As a side fact...It is interesting to read that Edison base lamp holders were required to have the screwshell adaquately recessed, and insulated, on lights before grounding became the norm.

  7. #7
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    Re: Hospital Operating Rooms Power Supply

    Bennie, although a fault on one side would only create a grounded system, the polarity of the system could be a concern.

    The system should be wired as to disconnect both legs as far as switching in the premesis, and with the polarity issue, switching of tools and appliances could be a problem. Some tools and appliances have double pole switches and some do not.

    If we were to eliminate GFCI's using this system we would have to know when we were becoming a grounded system to insure safety here. The characteristics would differ considerably between a metalic conduit and NM installation.

    These are a couple of issues that would need to be made fool proof. (maybe minor maybe not)

    I know we could keep GFCI's but, the safe level of operation could be a task to achieve and avoid nuisance tripping due to capacitve coupling (metalic installation) and individual leg impedance (overall leakage) adding to an imbalance between the two legs.

    Roger

    [ June 20, 2003, 01:42 PM: Message edited by: roger ]
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  8. #8
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    Re: Hospital Operating Rooms Power Supply

    Bennie, I always enjoy reading your posts, sometimes you are a bit cryptic with your aswers.
    Would you please elaborate on the cotton swap being the reason for isolation transformers..

  9. #9
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    Re: Hospital Operating Rooms Power Supply

    Alan: I like your use of words, I had to look up the definition of cryptic.

    I sometimes leave things out to see if anyone is paying attention

    The solution used to clean the skin makes the resistance very low. Current flowing through filter capacitors can become lethal. This current must be less than 10uA. Plus any current in the equipment will interfere with the current in the body and give false data.

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