wiring methods for docs office

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wortmanmechanical

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I am a small electrical contractor in a relativly small community. I have been asked to wire a small doctors office for an optomertrist.
Being that I do not do alot of commercial projects I am struggling with the correct method of wiring for this building. The building offical and plan review say that I can run romex throughout. I work with an elec engineer on a regular basis and he say's it falls under Article 517 Health Care Facility and that I should be using HCF wire for the redundant ground. I need some help any comments. The building is a wood frame construction.
 
Re: wiring methods for docs office

maybe a AHJ question. in this area,HCF or equal would be required in the patient crea areas.
 
Re: wiring methods for docs office

Yep... all the exam rooms (patient care areas) need done with health care cable (redundant ground AC cable). You can do your home runs in EMT if you also pull a ground in the EMT, or you can use the health care cable for the home runs.

For the office areas and waiting rooms (any area that's not an exam room or area where the patients are examined), you can use romex in the walls, and MC and EMT above the suspended ceilings.

This is the cheapest way I know of to wire a doc's office. The only thing that's differnet from normal office wiring is the use of health care BX in the exam rooms. Git r done...
 
Re: wiring methods for docs office

Originally posted by mdshunk:
Yep... all the exam rooms (patient care areas) need done with health care cable (redundant ground AC cable). You can do your home runs in EMT if you also pull a ground in the EMT, or you can use the health care cable for the home runs.

For the office areas and waiting rooms (any area that's not an exam room or area where the patients are examined), you can use romex in the walls, and MC and EMT above the suspended ceilings.

This is the cheapest way I know of to wire a doc's office. The only thing that's differnet from normal office wiring is the use of health care BX in the exam rooms. Git r done...
Click to expand...
OK, I know it's dangerous to ask "why" questions, but why do patient care areas require a redundant ground? In what way is this superior to a properly installed single ground on a circuit?

- Jim K
 
Re: wiring methods for docs office

Originally posted by jim k:
why do patient care areas require a redundant ground? In what way is this superior to a properly installed single ground on a circuit?
Click to expand...
Jim in my opinion it is because two is always more reliable than one.
 
Re: wiring methods for docs office

I am wiring one this week.What comes to my mind is would it not be better to have gfci protection ? And do the ceiling light fixtures need HCF wire to them or just to the switch?
There are 2 ceiling fixtures per exam room and i was told i had to run it to only the first fixture and the second could be looped from first on MC.This makes no since to me.
 
Re: wiring methods for docs office

Originally posted by jimwalker:
And do the ceiling light fixtures need HCF wire to them or just to the switch?
Click to expand...
Jim take a look at 517.13(A) and 517.13(B) be sure to read the exceptions they cover lights above 7'-5", switches and metal switch plates..
 
Re: wiring methods for docs office

Jim,
What comes to my mind is would it not be better to have gfci protection ?
Click to expand...
If invasive procedures are being done using electrical medical instruments, the trip point on a GFCI is too high by a factor of ten or more.
Don
 
Re: wiring methods for docs office

I have opened up a wall and reconnected EMT to the box connector enough times ( once ) to know why the British require that ALL metal conduits in ALL occupancies have a redundant grounding conductor, not just in hospitals.

Every explosionproof wiring that I have done had a redundant grounding conductor in it, either the equipment manufacturer's requirement, the boss's requirement, or the customer has seen enough broken conduits to know that he needs it. Also have put in a local ground rod for an aboveground fuel tank with pumps so that static electricity has a short path. A local ground rod also helps with damage similar to how 97% of lightning damage in a telephone cable plant comes from silent lightning and invisible lightning.
 
Re: wiring methods for docs office

So if i am reading this correct after the feed for the switch (is in the room)i could run Just normal MC

[ December 05, 2005, 05:56 AM: Message edited by: jimwalker ]
 
Re: wiring methods for docs office

Jim, it would have to be AC, the sheath would still have to be recognized as an EGC, you just wouldn't need an insulated conductor connection to the lights if they are 7'6" or higher.

Roger
 
Re: wiring methods for docs office

Try reading this to help in understanding why a redundant ground is used in patient care areas.

"517.11 General Installation ? Construction Criteria.
It is the purpose of this article to specify the installation criteriaand wiring methods that minimize electrical hazards by the maintenance of adequately low potential differences only between exposed conductive surfaces that are likely to become energized and could be contacted by a patient.

FPN: In a health care facility, it is difficult to prevent the occurrence of a conductive or capacitive path from the patient?s body to some grounded object, because that path may be established accidentally or through instrumentation directly connected to the patient. Other electrically conductive surfaces that may make an additional contact with the
patient, or instruments that may be connected to the patient, then become possible sources of electric currents that can traverse the patient?s body. The hazard is increased as more
apparatus is associated with the patient, and, therefore, more intensive precautions are needed. Control of electric shock hazard requires the limitation of electric current that
might flow in an electric circuit involving the patient?s body by raising the resistance of the conductive circuit that includes the patient, or by insulating exposed surfaces that might become energized, in addition to reducing the potential
difference that can appear between exposed conductive surfaces in the patient vicinity, or by combinations of these methods. A special problem is presented by the patient with
an externalized direct conductive path to the heart muscle. The patient may be electrocuted at current levels so low that additional protection in the design of appliances, insulation of the catheter, and control of medical practice is
required."
 
Re: wiring methods for docs office

Ok think i got it now.Did not know there was AC without a green wire.So then the plan to rum HCF 12-3 from switch to first light then 12-2 to fixture b won't help any .Will admit i am green in this area.
 
Re: wiring methods for docs office

"So if i am reading this correct after the feed for the switch (is in the room)i could run Just normal MC"

The switch can still be in the room, it cannot be in the "PATIENT VICINIY".

"Patient Vicinity. In an area in which patients are normally cared for, the patient vicinity is the space with surfaces likely to be contacted by the patient or an attendant who can touch the patient. Typically in a patient room, this encloses a space within the room not less than 1.8m (6 ft) beyond the perimeter of the bed in its nominal location, and extending vertically not less than 2.3 m (71⁄2 ft) above the floor."


"Exception No. 2: Luminaires (light fixtures) more than 2.3 m (71⁄2 ft) above the floor and switches located outside of the patient vicinity shall not be required to be grounded by an insulated equipment grounding conductor."
 
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