MRI wiring

[jdero]

Contractor is installing a new MRI in the local hospital. demo of existing MRI shows equipment wiring done in smurf tube. Manufaturer rep says that this is the way it is typically done. anyone have any experience with this, thanks.

 

[raider1]

I would call an MRI room in a hospital a patient care area.

517.13 would require the wiring methods used in the MRI room to be in a metal wiring method that itself qualifies as an EGC in accordance with 250.118.

Smurf tube would not work in a patient care area.

Chris

 

[Hendrix]

Contractor is installing a new MRI in the local hospital. demo of existing MRI shows equipment wiring done in smurf tube. Manufaturer rep says that this is the way it is typically done. anyone have any experience with this, thanks.

Never seen ent in hospitals. I think the rep is nuts.

 

[roger]

We normaly use EMT or alluminum in MRI's.

Roger

 

[dbuckley]

Just make sure that you dont have any iron or steel in your construction inside the MRI magnet's exclusion zone, the details of which will be in the MTI installation instructions, and may well be painted or signposted by the time you get there.

I can understand why smurf tube is used; its non-ferrous, and the copper wire inside is also non-ferrous, so no nasty magnetic accidents waiting to happen.

Have a google for what MRI magnets can grab; they are hellishly strong; theres a well reported fatality due to a patient being struck by a flying oxygen cylinder that got inside the exclusion zone...

 

[RETRAINDAILY]

I have done a couple and they all specked stainless steel fasteners, screws, and gutters

 

[RETRAINDAILY]

well the class 2 wiring can be done is in smurf tube ? :roll:
thats at least 80% of the machine
there machine has to be listed or have there own inspection so you need to do it like they say if I remember right

 

[dbuckley]

I have done a couple and they all specked stainless steel fasteners, screws, and gutters

Makes sense - stainless steel is approximately non-magnetic, as long as you've got the right stainless steel.

 

[steve66]

Just make sure that you dont have any iron or steel in your construction inside the MRI magnet's exclusion zone, the details of which will be in the MTI installation instructions, and may well be painted or signposted by the time you get there.

I can understand why smurf tube is used; its non-ferrous, and the copper wire inside is also non-ferrous, so no nasty magnetic accidents waiting to happen.

Have a google for what MRI magnets can grab; they are hellishly strong; theres a well reported fatality due to a patient being struck by a flying oxygen cylinder that got inside the exclusion zone...

That's all true, but it is also true that it is common to have EMT conduit and other metal items inside the room as long as they are securely fastened. If you think about it, I'll bet every receptacle has some steel in it.

The MRI vendor and techs. should be experts at what is allowed, although the smurf tube comment makes me wonder.

 

[roger]

Here is an EMT install in one MRI we did awhile back. This is the only wood framed MRI I have been involved with, all others have been standard metal studs. Typically the envelopes are copper (as shown here) or alluminum, there are some that have sheet steel envelopes.

Roger

 

[dbuckley]

That's all true, but it is also true that it is common to have EMT conduit and other metal items inside the room as long as they are securely fastened.

Thats the bottom line here; anything metal is going to be tugged at - hard - through its working life. When the magnet gets quenched metallic stuff is going to be released too. As long whatever is installed is up to those forces and will stay where its put, then all is well with the world.