Portable X Ray receptacle

[storeytime]

I am installing 2 - 240V, 50 amp Portable X ray receptacles in a surgery area at a hospital. It is an area where flammable anesthetics are used. Does this need to be fed out of the surgery area isolated power panel or can it be fed from regular power if it is mounted above 5 feet?

 

[roger]

Storytime, where is this hospital located? The U.S. and most modern countries do not use Flammable Anesthesia any more, it is basically third world counties that still use it if even that is the case now.

With that said, these receptacles should be fed from an Isolated source, it doesn't make sense to introduce a grounded system into an area served by Isolated systems. Think touch potential between the two sources, this can inadvertantly ground the Isolated source, of course this would alarm the LIM.

Roger

 

[storeytime]

Portable X Ray receptacle

Thanks for the reply Roger. It is a small hospital in central Texas. The head of maintenance told me it was flamable. I will check tomorrow with the head of surgery to make sure. Yeah, that makes sense about the touch potential. Thanks again.
Tim

 

[Smart $]

Have you checked that the X-ray units are listed as isolated power equipment? You can't put the receptacles on an isolated power system if the equipment is not listed for use on such—517.19(E)

Also, you stated Portable type, as in hand-carried. If by chance they are the Mobile type, which have a permanent base with casters and/or wheels, the receptacles have to meet the grounding criteria of 517.19(G).

 

[roger]

You're welcome.

smart, cord and plug connected items are not part of the "isolated power system equipment"

Also, you stated Portable type, as in hand-carried. If by chance they are the Mobile type, which have a permanent base with casters and/or wheels, the receptacles have to meet the grounding criteria of 517.19(G).

As does every receptacle in the room.

The Equipotential between all devices and conductive surfaces of fixed equipment in the room (including these xray receptacles) must be less than .01 ohm, see NFPA 99 4.3.3.1.6.2; this can only be achieved if all bonding is common.

Roger

 

[RHaggie]

My question would be if the Isolated panel is capable of delivering the short time KVA without affecting all other equipment

 

[roger]

My question would be if the Isolated panel is capable of delivering the short time KVA without affecting all other equipment

It would take a seperate panel altogether. The Isolated Panels serving the general receptacles would be 120 volt panels, there would have to be a seperate 240 volt panel for the xray receptacle(s)

Roger

 

[Smart $]

...

smart, cord and plug connected items are not part of the "isolated power system equipment"

I see you choose your wording wisely, as "cord and plug connected items" are [almost ] always referred to as "cord- and plug-connected equipment". If only the CMP chose as wisely I/we wouldn't have as many misinterpretations...

Isolated Power System Equipment... all electrical systems have supply equipment and utilization equipment. Take either out of the picture and no system "Hey, guys, I have power on this receptacle!" Let's plug our equipment in here. Darn, the plug don't fit... must not be permitted on this system."

Isolated Power Supply Equipment... any confusion in this terminology? Hmm... I wonder, how long has the term "Power Supply" been around?

Seems more and more that CMP's want to coin new phrases while they're making Code and relying more heavily on supplementary documentation than ever before. Is it just me that sees this?

Anyway, while we're on the subject of isolated power "systems", perhaps you can clarify 517.160(A)(5) for me. It appears there is no provision for a 4-wire system. It says the third conductor for 3? is yellow then it goes on to discuss 125V recept's with orange always on the typically-grounded terminal. Then, the way it reads if a 1? supply, brown is connected to the "hot" terminal... for 3? either brown or yellow on the "hot". So where's the provision to utilize the third phase? If it is "125-volt" 3?, you can't use brown and yellow to power a "125-volt" receptacle. So what's the point of even mentioning 3? unless the receptacles determine the color of conductor and what circuit or buss they land on in the panel has no bearing?!!! I'm confused.

BTW, can anyone clarify this without having to resort to or draw on their knowledge of supplementary documentation?

 

[RHaggie]

It would take a seperate panel altogether.
Roger

That's correct. And wouldn't that panel need to be monitored by LIM since it would be introduced to the patient care vacinity? In other words, is it permissible to have the patient exposed to two grounding schemes and separate ground paths that might endanger the patient? Doesn't take much ground current at all with a needle is in the vein to cause death.
FYI.
In OR's today, it is not flammable anesthesis that is the reason for these isolated systems; it is the ability for an electrical fault to occur and be identified during a proceedure at a safe level. allowing it to be cleared without shuting the equipment - and proceedure- down.

 

[roger]

Smart, first of all, (leaving the xray receptacle out of the conversation) general use receptacles in Isolated Power System served areas (besides being HG) are plane Jane three wire 15 or 20 amp devices and any house hold item can be plugged into them. In most OR's there are normally Boom Boxes plugged into a system receptacle if there is not a stereo permanently installed in the room. The monitors are quite often from Best Buy, Circuit City, Walmart, or what have you. Out goes the special equipment argument.

As far as the 3? is concerned, scince there is no grounded conductor used or necessary, any combination of two conductors of Brown, Orange, and Yellow would be all that is needed to supply 120 nominal volts to any one receptacle.

What two busses is used for any one circuit would make no difference electrically.

RHaggie, Yes this 208 or 240 volt Isolated Panel would be connected to it's own LIM so you would not need to worry about

In other words, is it permissible to have the patient exposed to two grounding schemes and separate ground paths that might endanger the patient?

the patient would not be exposed to any grounding scheme or ground path.


BTW, I appreciate your "FYI" but rest assured I already knew this.

Do a search for Isolated Power and you'll see this is the case and FWIW, I have spent most of my career in Hospital construction.

Roger

 

[Smart $]

Smart, first of all, (leaving the xray receptacle out of the conversation) general use receptacles in Isolated Power System served areas (besides being HG) are plane Jane three wire 15 or 20 amp devices and any house hold item can be plugged into them. In most OR's there are normally Boom Boxes plugged into a system receptacle if there is not a stereo permanently installed in the room. The monitors are quite often from Best Buy, Circuit City, Walmart, or what have you. Out goes the special equipment argument.

As far as the 3? is concerned, scince there is no grounded conductor used or necessary, any combination of two conductors of Brown, Orange, and Yellow would be all that is needed to supply 120 nominal volts to any one receptacle.

What two busses is used for any one circuit would make no difference electrically.

...

Already had the first part of your response pegged.

As to the wiring, if I'm getting the correct picture, each receptacle circuit would be landed on a 2P breaker, one wire Orange, the other Brown, regardless of phase? A yellow conductor would only enter the picture if you needed a 3? circuit, using a 3P breaker and again regardless of phase, right?

 

[roger]

Already had the first part of your response pegged.

As to the wiring, if I'm getting the correct picture, each receptacle circuit would be landed on a 2P breaker, one wire Orange, the other Brown, regardless of phase? A yellow conductor would only enter the picture if you needed a 3? circuit, using a 3P breaker and again regardless of phase, right?

Smart, you are getting the picture, and you are correct in your post.

However, dealing with the single phase system, the orange conductor shall be the silver connected conductor as you posted earlier, this is not an electrical issue as you know (60 volts-60 volts), it's purpose is identification of phase connection to the device only.

Roger