What exactly does "Hospital Grade" mean?


I plan on changing my outlets since it seems like a cheap enough tweak and most here on the forum agree that it makes a difference. But what actually IS the physical difference between hospital grade and non-hospital grade outlets?
studioray

If you really want the ultimate plug/receptacle system you should look at the HubbleLock Hospital grade system. Be prepared for sticker shock!

I just wanted to add, in addition to the robustness of the connection and overall build quality, hospital grade receptacles are built to be wired with a redundant ground conductor (required by NEC Article 517, Health Care Facilities). It will NOT do this on it's own however. You need to wire back to the panel with hospital grade AC (aka hospital grade BX) or hospital grade MC (not as common). With the AC/BX cable you have the metal armor w/ drain wire as your first ground path (which is how regular AC/BX works) and an additional insulated conductor for a second redundant ground (unique to hospital grade BX). With hospital grade MC (uncommon), you have two insulated grounding conductors (instead of one, which regular MC has). Note the metal armor on MC cable is not listed as a ground.
Quote
Chapter 4 of NFPA 99 (2005 edition) addresses the electrical systems in health care facilities. It requires the electrical installation to be in accordance with NFPA 70, National Electrical Code (4.3.2.1). Following are some of the commonly referenced requirements:

Receptacle Testing


Receptacle testing in the patient care area includes confirming the physical integrity of each receptacle through visual inspection (4.3.3.2.1), confirming the continuity of grounding circuit (4.3.3.2.2), and verifying correct polarity of hot and neutral connections (4.3.3.2.3). In each receptacle, the retention force of the grounding blade should not be less than 4 ounces (4.3.3.2.4).

The testing of hospital-grade receptacles at patient bed locations and in anesthetizing locations shall be performed after initial installation, replacement, or servicing of the receptacle. Additional periodic testing in patient care areas should be performed at intervals determined by performance data.

Receptacles used at a patient bed and in anesthetizing locations that are not listed as hospital grade should be tested at intervals not exceeding 12 months (4.3.4.1). It must be noted that not all nonhospital-grade receptacles are required to be tested at intervals of 12 months. This requirement of annual testing applies only to those nonhospital-grade receptacles that are installed where hospital-grade receptacles are required for new construction.

Leviton Hospital grade plug and receptacle testing.

Hubbell white paper for testing of hospital grade receptacles used in Canada.

Cheap basic Receptacle tension tester.
No one at a hospital checks the force required to remove a plug.
(My boss is going to laugh when he hears that.)
08-09-06: joemh22@yahoo.com

joemh22@yahoo.com,

Really.....
So did your boss laugh?
Switching to a duplex outlet without nickel plating on the internal brass components is not a bad thing. Using some contact cleaner with it is even better. My house, which is only a few years old has the newer, designer outlets and switches. These things are junk inside but cost more, go figure. I recommend the hospital grade outlet just for a tighter, more secure connection.
I tried them all and I did not noticed any difference. I have a BAT VK-6200 and it works the same in a PS Audio Duplex receptacle as it does on a $0.49 Home Depot cheapie.
"Hospital Grade" takes the place of "Mil-Spec" now that the U.S. healthcare system has overtaken the Military with regards to power and waste.
Like everything else in a hospital it probaly just means they charge 5 times what it is worth!
I put a bunch of Porterports into my system and there was a very notable improvement. Of course, considering what came out of the walls in the way of really cheap recepticles, this was to be expected. Not an expensive upgrade.

Well worth it.
Facts:
Hospital grade plugs provide more robust grounding than a regular plug. They are built to a better quality. Grounding and isolation transformers are very important to medical equipment. The 15 and 20 amp (three prong plugs) are not suitable for use around flammable materials. There are explosion proof 15 and 20 amp hospital grade plugs that look totally different than a regular plug. You have to insert these turn them a quarter of a turn. These are usually found in older operating rooms. No one at a hospital checks the force required to remove a plug.
(My boss is going to laugh when he hears that.)

I am a biomed tech and I work on and test medical equipment.
Jea48, I find it interesting to know that the "pull pressure" of hospital grade recepticles is tested for the hospital environment. I didn't know that and I work in a hospital. However, I'm sure our maintenance personnel are aware of that. One thing to note, at least in our hospital, is that the red recepticles are the only recepticles that are used for normal power and power from the back-up generators. The red recepticles are used for computers, ventilators, etc. Also, it takes between 10 to 15 seconds for the generators to come on line, so there is a slight interruption in power, except for anything also plugged into a battery supply. Our ventilators have a builtin backup battery supply of about 30 minutes. Thanks for the education!
Hi Jae48, yes I do have one dedicated line coming from the main circuit breaker box at present. Right now it only contains just a consumer grade receptacle - meaning one dual outlet. I have an Arrow Hart 8200 on the way to me, which I've read some good things about, and so that will replace the outlet that's there.

Although I've been an Audiogon member for awhile, I've only recently stumbled upon the whole clean power/dedicated line thingy, and as of right now cannot even tell you which components are plugged into the dedicated line. I figure when the AH8200 comes, I'll either 1) Run only the amp and pre-amp from the dedicated line and run the PC (which is my CD player) and everything else from a common house line, or 2) Do the "split everything off of one outlet" approach and see how that sounds.

In my case, "everything else" is a lot of audio recording gear as my main listening place is also my workplace, which is a recording studio. So I've often got at least a dozen things on at one time that never get shut off and remain on constantly: outboard effects processors, microphone preamps, mixing boards, power conditioners, etc.. I know that this is not the audiophile best case scenario, but I spend only enough time at home to sleep, and so my studio has become my listening room.

Cheers,
Ray
Studioray, I installed the Hubbell 5362 outlets for my ARC VT50 power amp and my Sonic Frontiers Line One preamp. Plugged things back in and turned the system on. Right off I could hear a difference. As I have read from others the bass was deeper. I first started with a Female vocal and did notice siblence sounds, the dreaded sss sss. I was hoping that was due to the fact the outlets were new and needed some break-in time. For lack of anything else I could think of to plug into the two outlets and let them cook for about 24 hours, I used two table lamps with 3 way bulbs. I turned the switches on the lamps to the highest wattage. Tonight I unplugged the lamps and plugged back in the equipment. Turned things on, let the system warm up for about a half hour and sat down for a listen. Siblence were gone. The bass from my system is deeper. The sound is darker, sound stage more layered. The Hubbell 5362 beats the Leviton Hospital Grade outlets hands down. It has to be that steel supporting yoke,strap. Or maybe the Hubbell is more dampened.

I still have to change the outlet for the CDP, one thing at a time.

And then there is the outlet cover plates. I am presently using the Leviton magnetic Stainless steel plates with a nylon trim screw. I know Nerspellsner, I am guilty, busted!
This weekend I will experiment with the nylon outlet cover plates.

Also I am Still going to try the Hubbell 8300H Hosp Grade duplex outlets. I just need to make up my mind whether I am going to buy the Cyroed outlets.

Studioray, You did not mention in your thread if you have dedicated audio branch circuits.
Nerspellsner, I found a few errors in the Stereophile article.

Besides that one you mentioned,

The Hubbell HBL8300I receptacle. The I does not stand for plated, it stands for ivory.

The picture of the two outlets, the top outlet sure looks to me to be the non nickel plated Hubbell HBL8300H, not the plated HBL8300.

On the whole they did a pretty good job with the article for being laymen when it comes to electrical.
Jim
What nomenclature did Robert read claiming that hospital grade outlets are guaranteed spark free in the Stereophile article? How can this be true?
Follow Up
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"Next I tried The HBL8300. Imho the plug pushed in harder and pulled out harder. Is it due strictly to the Hot and Neutral contacts or is it due to the hosp grade ground connector???"
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I did not want to leave the impression that the difference in tightness was due to the ground prong, it was not. I did try the test with a two wire cord and plug also....
>>>>>>>>>>>>

>>"It means that someone has been clever enough to charge audiopiles who don't know anything about electricity a ton of money for -- wire.'<<
[Bojack]
>>>>>>>>>

Bojack did read page 2 of the link I provided.
http://stereophile.com/artdudleylistening/1103listening/index1.html
It means that someone has been clever enough to charge audiopiles who don't know anything about electricity a ton of money for -- wire.
>>"Jea48, can you please explain the benefit of "Contact Pressure"?'<<
>>>>>>>>>
Here is some reading material for you. I am not promoting their product.
http://stereophile.com/artdudleylistening/1103listening/
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You will notice in one of my posts I mentioned the Hubbell 5362, 20 amp outlet. I stopped by an electrical supply house tonight and picked up a couple of them.

I was given a couple of the HBL8300 (nickel plated) 20 amp hosp grade outlets a while back. Never hooked them up after reading the bad reviews about them.

For what it is worth I grabbed an extra PC I had laying around. I plugged the PC into one of the new 5362 outles and pulled it out feeling the the pressure of the contacts.
Pushing in, pulling out. LOL, LOL...Can't believe I just said that!

Next I tried The HBL8300. Imho the plug pushed in harder and pulled out harder. Is it due stricly to the Hot and Neutral contacts or is it due to the hosp grade ground connector???
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01-30-06: Nerspellsner
>>"Jea48, I have heard of that device but I have never used it. I remember hearing that the device is connected to the ground pin only. It has to stay connected to a hospital grade outlet with 4 oz of pressure for a certain amount of time."<<
>>>>>>>>>

After reading your post now that I think about it your are right it tests the ground receptacle of the outlet.
I still like your testing method though. Imo only the Hubbell would survive, that is the HBL8200 and the HBL8300 hosp grade.
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Jim
Post removed 
Hospital grade outlets cannot overcome the tenacity of human folly. In South Africa, a hospital noted that patients in a particular bed in the ICU unit were found dead on Saturday morning on a regular basis. Suspecting a serial killer, investigators set up a surveillance camera. What it caught was a cleaning person coming in on Friday night. That person would unplug the respirator for that killer bed, plug in the vacuum cleaner, clean the room, then plug the respirator back in when he/she was done.
Jea48, can you please explain the benefit of "Contact Pressure"? I mean I know what it means, but are you saying that the better contact pressure of hospital grade outlets is desireable because of an enhanced electrical flow, or as some others seem to be suggesting, that the benefits are in the power chord not being pulled out too easily/accidentally???

Thanks,
Ray
All outlets get looser as stuff is plugged in and out many times. A "pull test" is a practical way for the maintenance staff to determine how far the degradation has gone, and when it is time to replace the outlet. Wearout should not be a concern for audio applications since it does not involve frequent plug/unplug cycles.
Jea48, I have heard of that device but I have never used it. I remember hearing that the device is connected to the ground pin only. It has to stay connected to a hospital grade outlet with 4 oz of pressure for a certain amount of time. I concur with your statement about removing a plug under a load from an outlet will cause an arc, regardless of the type of outlet.
Nerspellsner, LOL, I never heard of that test, LOL.
You do know there is a device that plugs into the outlet and while extracting it, will give you the resistance to the pulling action in ounces...
Jim
>>"And I don't think that requiring "X" amount of force to remove a plug from an outlet makes the outlet superior for our purposes although a snug fit is obviously necessary."<<
[Studioray]
>>>>>>>>>>>

It's Contact Pressure......You misssed the whole point.
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It means

1) more expensive
2) not always covered by insurance and
3)linked to fear

so you will be less likely to protest and just pay the extra money.
Post removed 
Thank you all for the replies, especially Albertporter - that pdf seemed to be exactly what I was looking for. However, upon reading that pdf, it seems that the primary differences are "grounding reliability, assembly integrity, strength and durability." None of which seem to me to be capable of affecting the sound of our equipment... or am I missing something? And I don't think that requiring "X" amount of force to remove a plug from an outlet makes the outlet superior for our purposes although a snug fit is obviously necessary. Does the "grounding reliability, assembly integrity" somehow make the outlets less susceptible to rfi noise and the like?

Or is the audiophile key here the fact that these recepticles come in a preferred choice of metal make-up, e.g. brass w/o a nickle finish?

So to summarize, what is it about these hospital grade differences that make them sound better???
Mapleleafs3 and Jea48

It should be noted that a loose electrical contact can and will heat up. This is where the fire hazard exists. The extra resistance will create hotter temperatures. They will also spark.

So, no loose contacts so that sensitive equipment does not loose power (so many busy feet in a hospital) but also to avoid hotter than normal temperatures at the plug and in the receptacle.
One of the tests is the drop test. It goes something like this. The outlet is mounted 50 inches from the floor. A 3 foot cord with a hospital grade male cord cap and a 8 pound weight at the end of the cord is plugged into the hospital grade outlet. The weight is dropped straight down at the outlet height. The cord must stay plugged in and no damage done to the outlet to pass the test for hospital grade.
Hospital grade sockets perform this function well because they're designed for health care environment where uninterrupted power is important.

An uninterrupted power in the hospitals suppose to be before it reaches a recepticle. In case of a blackout every hospital has an alternate power generator.
>>"Jea48, please find the technical data to back up your statement. Dont just disagree , prove your statement"<<
[Mapleleafs3]
>>>>>>>>>>

This may be on a grand scale but you will get the idea...
http://205.243.100.155/frames/longarc.htm
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Jea48, please find the technical data to back up your statement. Dont just disagree , prove your statement
>>"It means it can be used in ares where there are flameable materials."<<
[Mapleleafs3]
>>>>>>>>>>>

Sorry, not true....If a plug is pulled from an outlet and there is a connected load, current flowing, there will indeed be a spark. Hospital grade receptacle or not.
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Jim
it means that they are of such quality that the sonics from the ventilators, monitors and defibrillators are first-rate. at least that's what i hear after my 14th day in a row.
It means it can be used in ares where there are flameable materials. Supperior contact and will not provide a spark if pulled from the outlet./
There are readily-available 3-pin plugs (and sockets) that twist to lock.
I use exactly that for my 240 volt connections and have for several years.

However, some aftermarket power cords void warranty if modifications are made, and if wired improperly could cause damage to your equipment or your home.

The 120 Volt Hospital grade sockets I provided a link to as well as other aftermarket high quality outlets conform to roughly the same size specifications (fit in existing box) and wire identically to common household outlets.

In other words, a heavier, higher grade product in the wall that requires no modifications to existing male plugs.
">>Reading it I notice that "Hospital Grade" means it has certain characteristics, like tolerance of "Abrupt removal" (yank the wire) which are probably important in the Hospital environment, but which IMHO are not relevant to the outlets we use for audio systems."<<
[Eldartford]
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Probably true.

Different Hospitals may have differering standards for what they require for the contact pressure of a hospital grade receptacle. One hospital that I know of in particular in my city, their Bio-Med department, requires a minimum of 4 ounces of resistance when removing a plug from an electrical outlet. By the way the only two manufactures of hospital grade outlets the hospital specs in any new installations or replacements is Hubbell and Leviton.

Key word resistance, contact pressure.
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On another forum, Audio Asylum, a non hospital grade receptacle that is spoken of very highly is the Hubbell 5362 (5-20R) receptacle. A non plated brass contacts with a brass non plated receptacle supporting yoke, strap.

Another recommended Hubbell receptacle is the HBL8300H (5-20R) receptacle. Again non plated brass contacts and a brass non plated supporting yoke. Buy the way this is the receptacle that Albert Porter uses in his Cryoed
"Porter Ports".

I presently am using the Leviton 20 amp hosp grade outlets which I think sound very good. The Leviton outlet uses non plated brass contacts, but unlike the Hubbell outlets I have described where the Hubbell uses a brass supporting yoke, the Leviton uses a steel supporting yoke. Magnetic material.... I have read many negative comments in regards to a steel supporting yoke, strap.

So now I will buy the HBL8300H and the 5362 Hubbell recepts and find out for myself.

What is the rave out there now, the best outlet?
Many talk of the Oyaide SWO-XXX
http://www.audioexcellenceaz.com/oyaideoutlets.htm
Albertporter...Of course a tight grip would be important for a heavy PC, but the "Hospital Grade" designation does not seem to offer this feature any better than commercial grade (as you note).

When I was involved with heavy (64-pin) connectors and cables we usually provided for strain relief support of the cables, even though the connectors were a locking type.
It seems to me that, for some of the audio equipment power cables I have seen, reliance on the simple 3-pin outlet would be unacceptable no matter how tight the grip. There are readily-available 3-pin plugs (and sockets) that twist to lock. These are, I think, used for higher amperage 220 volt applications, and I often wonder why audiophiles have not discovered them.
It's nice for those of us that have heavy weight power cables, because they're held more securely.

Hospital grade sockets perform this function well because they're designed for health care environment where uninterrupted power is important.

There are also several commercial grade sockets that have excellent grip. Almost any brand "premium socket" is superior to the .49 cent ones used in construction of new homes and apartments.

Dozens of companies provide premium aftermarket outlets, and like power cables, some audiophiles use them and some do not.
Thank you Albert for the detailed info.

Reading it I notice that "Hospital Grade" means it has certain characteristics, like tolerance of "Abrupt removal" (yank the wire) which are probably important in the Hospital environment, but which IMHO are not relevant to the outlets we use for audio systems. They would be a good idea for some other plugs in my house (the ones that the vacuum cleaner gets plugged into).