Updating grounding system

[anbm]

If we have an old hospital (built around 1970) and there is no grounding system in the building, conduits run without ground wire. Now if owner want to bring building up to code with grounding system for all new panels, transformers even existing system. What is the best way to accomplish this?
(driving ground rods to serve all new equipment?).

I know that by code requirement, the equipment ground wire has to be run with other wires, so if we want to upgrade all existing panels to have ground wire, sound like it is not possible and may cost a lot. Thanks!

 

[Dennis Alwon]

An EGC wire is not always required. If this has metal conduit or MC cable , etc, then the raceway itself is a ground.

 

[augie47]

Big question now concerns the end use of the building.
Hopefully not health-care.
Other than health care you may not have a problem depending on the wiring system. Proper grounding was possibly maintained by one of the wiring methods in 250.118.
If not, ground rods would be of no use..see 250.4(B)(4)

 

[benaround]

sound like it is not possible and may cost a lot. Thanks!

I like the second part,

 

[bob]

If we have an old hospital (built around 1970) and there is no grounding system in the building, conduits run without ground wire. Now if owner want to bring building up to code with grounding system for all new panels, transformers even existing system. What is the best way to accomplish this?
(driving ground rods to serve all new equipment?).

Absolutely not. That's the worst thing you can do.

I know that by code requirement, the equipment ground wire has to be run with other wires, so if we want to upgrade all existing panels to have ground wire, sound like it is not possible and may cost a lot. Thanks!

The code allows the conduit to act as an EGC. You may want to inspect the conduit to see if it has corroded to the extent it is not usuable.

 

[anbm]

This is a hospital, patient care area do need additional equipment ground wire even using metal conduits. (NEC-517)

 

[George Stolz]

Right, but the entire hospital is not a patient care area. Article 517.

 

[kwired]

Also note that 517.13 is the section that requires the metal raceway along with grounding conductor. It only applies to branch circuits in patient care areas and exception 2 may eliminate some luminaires and switches from this requirement.

I am running into the same thing on an older hospital where they want to do some minor remodeling and add receptacles. Everything is in metal raceways in this 1950's hospital. Only thing that needs changing to meet current code is grounding conductor to patient care areas, use of hospital grade receptacles in patient care areas, and some updating of emergency power system that is non existant in the 1950's building but is installed on the newer annex.

 

[Philip Barr]

The governing body of the health care facility determins which areas are classified as patient care areas, it's feasable that a patiant in a hospital may take a walk in the corriordor as directed by the doctor or nurse and use the water fountain, should this area then be considered part of the patiant care area. As the electrician we cannot determine that so unless you have an approved seal deliniating one area from the next, you
must assume the entire facility up to 7-1/2' aff will require a redundant ground.

 

[kwired]

The governing body of the health care facility determins which areas are classified as patient care areas, it's feasable that a patiant in a hospital may take a walk in the corriordor as directed by the doctor or nurse and use the water fountain, should this area then be considered part of the patiant care area. As the electrician we cannot determine that so unless you have an approved seal deliniating one area from the next, you
must assume the entire facility up to 7-1/2' aff will require a redundant ground.

It is also feasable that a patient may go outdoors or even to their own home and then return in some cases. Yes governing body will determine which areas are classified as patient care areas. In most cases a corridor will not be one of these areas under normal circumstances. A corridor that serves mostly patient rooms maybe has a little better chance of being classified this way but the intent most likely will be that the medical procedures be done in the patient rooms as much as possible.

Emergency situations can make patient care take place anyplace including the parking lot. I know someone who was shot during a robbery attempt in a hospital parking lot while there to visit a patient. Don't think they intended for patient care in this area but stuff happens.

 

[anbm]

How do you update extsing circuits in patient care area without equipment ground wire? Repull ground wire for all circuits? Or leave existing circuits alone and only do this for new circuits? I guess we have to add new equipment ground bar in panel + bond xfmr grounding electrode wire to new grounding system if possible?