isolated gronding

[liquidtite]

Im working in a hospital and the journey man that im working for said that only the critical care receptacles need isolated grounds and not regular outlets witch makes sence just wanted to see if this was the norm.Also what is the purpose of isolated grounding to isolate any groundfaults ?.

 

[iwire]

Just to make sure we are talking about the same thing

Are you meaning isolated grounds that generally terminate in an orange outlet or are you asking about redundant grounding required in hospitals?

 

[don_resqcapt19]

Isolated (insulated) grounding receptacles are not permitted in patient care areas.

517.16 Receptacles with Insulated Grounding Terminals. Receptacles with insulated grounding terminals, as described in 250.146(D), shall not be permitted.

 

[texie]

Just to make sure we are talking about the same thing

Are you meaning isolated grounds that generally terminate in an orange outlet or are you asking about redundant grounding required in hospitals?

Good point. At first read I took the OP to mean isolated, which of course are no longer allowed as it conflicts with the required redundant ground.

 

[liquidtite]

Just to make sure we are talking about the same thing

Are you meaning isolated grounds that generally terminate in an orange outlet or are you asking about redundant grounding required in hospitals?

im not familiar with redundant grounding? these outlets were red with a green sticker on them and witch are near the med gas station they were already instaled with wips attached to them we just brought our feeds to the outlets im assuming its isolted grounding bc the ears on the plug are not bonded to the green grounding screw on the outlet.but we also brought two sets of gounding conductors to other specific plugs aswell

 

[roger]

im not familiar with redundant grounding? these outlets were red with a green sticker on them and witch are near the med gas station they were already instaled with wips attached to them we just brought our feeds to the outlets im assuming its isolted grounding bc the ears on the plug are not bonded to the green grounding screw on the outlet.but we also brought two sets of gounding conductors to other specific plugs aswell

There is a serious problem with what you describe, see Don's post.

All the receptacles in Patient Care Areas must be bonded to the metalic box regardless of whether or not they are Critical or Normal power sources. The raceways circuit conductors to these boxes must comply with all of 517.13. If these receptacles are in a Patient Bed Location they must be Hospital Grade which will be identified with a green dot, not to be confussed with a green triangle.

Roger

 

[liquidtite]

we did bond the receptalces to the metal boxes we brought one ground that he said is our isolated ground went to the green grounding screw on the receptacle and the other ground bonded to the metal box.

 

[roger]

we did bond the receptalces to the metal boxes we brought one ground that he said is our isolated ground went to the green grounding screw on the receptacle and the other ground bonded to the metal box.

Although it sounds like you have it covered it is not for the reasons you are stating. With that said, in a patient care area you can not have an "isolated ground" period, you must have a raceway that in itself is an EGC recognized in article section 250.118 and an insulated ground wire per 517.13(B), these two EGC's must be bonded (tied) together to give redundancy to each other. It sounds as though the Jman pulled two insulated conductors and this was unnecessary but, if they are both bonded to the raceway in one way or another it is fine.

Did you check to see if the receptacles had a green dot or did they have a green triangle?

Roger

 

[glene77is]

Although it sounds like you have it covered it is not for the reasons you are stating. With that said, in a patient care area you can not have an "isolated ground" period, you must have a raceway that in itself is an EGC recognized in article section 250.118 and an insulated ground wire per 517.13(B), these two EGC's must be bonded (tied) together to give redundancy to each other. It sounds as though the Jman pulled two insulated conductors and this was unnecessary but, if they are both bonded to the raceway in one way or another it is fine.

Did you check to see if the receptacles had a green dot or did they have a green triangle?

Roger

Roger,
Agreed.
Leaking voltage/currents can harm/kill a patient with intravenous catheters.

Once had an administrator berate me for requesting a fix to a "switch on cord-plug" method that had been used since day one.
His wife was a nurse in the patient care area, and she grabbed the cord-plug and was 'shocked' to the floor. hmy:
The admin apologized in person, and authorized a fix.

Everything must be grounded, and more. Also, per code, as stated.

To the point,
Please differentiate between the "green dot" and the "green triangle".
Is the "dot" for hospitals and the triangle for computer lines ? ? ?

 

[roger]

To the point,
Please differentiate between the "green dot" and the "green triangle".
Is the "dot" for hospitals and the triangle for computer lines ? ? ?

Hospital Grade receptacles are identified with a green dot, Isolated Ground receptacles are identified with a triangle.

Roger

 

[liquidtite]

maybe im not using the proper electrical terminalogy,also this is my first hospital job ive been on aswell.But the jman im working with used the term isolated ground .Everything is in conduit, weve pulled a grounding conductor for every device But for specific receptacles I belive he said cridical care we pulled to sets of grounds one that is bonded to the meatal boxes and one strictly for the receptacles that we will provide and receptacles that are already provided at the med gas stations that have a green dot.

 

[roger]

maybe im not using the proper electrical terminalogy,also this is my first hospital job ive been on aswell.But the jman im working with used the term isolated ground .Everything is in conduit, weve pulled a grounding conductor for every device But for specific receptacles I belive he said cridical care we pulled to sets of grounds one that is bonded to the meatal boxes and one strictly for the receptacles that we will provide and receptacles that are already provided at the med gas stations that have a green dot.

Liquidtite, don't take this wrong but, given the fact that the jman is using the term "isolated ground", pulling two insulated EGC's for either system be it Normal or Critical, terminating one to the box and one to the device, shows he doesn't know the correct way to wire patient care receptacles. All he needs to do is read article 517.13 and install the circuit conductors accordingly.

BTW, the receptacles with the green dot are HG.

Roger

 

[liquidtite]

i dont take it the wrong way thats why im here

 

[liquidtite]

Liquidtite, don't take this wrong but, given the fact that the jman is using the term "isolated ground", pulling two insulated EGC's for either system be it Normal or Critical, terminating one to the box and one to the device, shows he doesn't know the correct way to wire patient care receptacles. All he needs to do is read article 517.13 and install the circuit conductors accordingly.

BTW, the receptacles with the green dot are HG.

Roger

so what is hg and how do you wire hg rececptacles.also what method is it when you terminate one ground to the box and one to the device?

 

[GoldDigger]

so what is hg and how do you wire hg rececptacles.also what method is it when you terminate one ground to the box and one to the device?

HG stands for Hospital Grade and it is more tightly specified to reduce the opportunities for faults that could be hazardous to the patient or staff, and also less likely to fail in normal use.
When the receptacle itself has an internal connection between the yoke and the green screw, and you terminate a separate ground wire to (box and screw) that is one way to provide double or dual or redundant grounding.
It means that if either one of the ground paths is interrupted, there is still a fully rated safety ground connection.

An isolated ground receptacle does not have a connection between the yoke and the green screw and only the green screw connects to the ground hole of the receptacle. It is used for special purposes and is not used in patient care areas.

 

[roger]

Liquidtite, GoldDigger's post covers it perfectly.

Roger

 

[glene77is]

Hospital Grade receptacles are identified with a green dot, Isolated Ground receptacles are identified with a triangle.

Roger

Thanks to Roger.

Working for a commercial contractor,
We have used "green triangle" Isolated recepticals in Computer Related areas.
It was in the design plans to "suppress noise". :happysad:

While at the University hospital,
I specified "green dot" Hospital grade recepticals in any "Patient Areas", which was just about everywhere.
In any ICU areas, I specified Isolation transformers, due to the use of intravenous catheters and attached monitors.
I did a study on this issue, and it was very interesting what can happen in an ICU environment. :happyyes: