I think it means use them unless the risk assessment says don't, but I agree that it's very ambiguous.

The whole thing seems ambiguous.  Does "not required to be installed" mean "shall not be installed" or "may be installed if you wish"?

I think it always means you can install them or not as you wish - but under some conditions you should do an RA to reach that decision. Presumably in the other case you can toss a coin.

Not perhaps  the finest wording.

Less flippantly

lets look at what it all means _ think basically Group 0 locations might uin clude the waiting room and nurses office, and a power cut is likely to lead to no more inconvenience than a school or office other more or less public place.

Group 1 and 2 things may be being done to patient, internally or externally, where the risk to patient is increasing, and the chance of un-authorised equipment being plugged in is low and the wiring will be to a known standard, we hope.

9.3 Definitions
9.3.1 Medical location
Location intended for purposes of diagnosis, treatment including cosmetic treatment,
monitoring and care of patients.
9.3.2 Patient
Living being (person or animal) undergoing a medical, surgical or dental procedure.
Also, a person undergoing treatment for cosmetic purposes may be regarded as a
patient.
.....
Part of medical electrical equipment that in normal use necessarily comes into physical
contact with the patient for the ME equipment or an ME system to perform its function.

9.3.5 Group 0
Medical location where no applied parts are intended to be used and where
discontinuity (failure) of the supply cannot cause danger to life.

9.3.6 Group 1
Medical location where discontinuity of the electrical supply does not represent a
threat to the safety of the patient and applied parts are intended to be used:
(a) externally; or
(b) invasively to any part of the body, except where Group 2 applies.

9.3.7 Group 2
Medical location where applied parts are intended to be used, and where discontinuity
(failure) of the supply can cause danger to life, in applications such as:
(a) intracardiac procedures; and
(b) vital treatment and surgical ope

Mike.

Agreed save that I don't find it ambiguous.

Do a risk assessment and install AFDD if the outcome indicates that they should be used.

The intent of the last sentence is to give the designer and installer opprtunity to use an AFDD in a Group 0 location where they may consider an AFDD is of benefit to the building occupiers.

An example of this could be where patients purposely intend to create arcs in order to create an ignition source for lighting of materials such as cigarettes etc. The type of location where this risk exists are typically Group 0 locations.

The intent of the last sentence is that ordinarily AFDDs are not required. However, in order to counteract a specific risk (normally identified by clinicians), AFDDS shall be provided where a risk assessment demonstrating the use of AFDDs will avoid of such a specific risk. 

In my opinion guidance is missing on this matter.

The regulation does not use the terms "shall not be installed" as this is quite restrictive. Such a restriction would impair the designer's ability to use equipment appropriately. (I know you could use Reg 120.3 but permitted exceptions are difficult to apply correctly) Hence the wording "not required to be installed" was believed to give the experienced designer opportunity to apply the requirements appropriately.

Just for the record, AFDDs should not be installed on a Medical IT system. 

euringharris said:

An example of this could be where patients purposely intend to create arcs in order to create an ignition source for lighting of materials such as cigarettes etc. The type of location where this risk exists are typically Group 0 locations.

The intent of the last sentence is that ordinarily AFDDs are not required. However, in order to counteract a specific risk (normally identified by clinicians), AFDDS shall be provided where a risk assessment demonstrating the use of AFDDs will avoid of such a specific risk. 

Seriously! It is decades since it was almost impossible to see from one end of a ward to another because of the patients' smoke generated by the very same people whose smoking had caused their heart attacks, strokes, and respiratory problems. In any event, that would be a Group 1 location.

I don't think that clinicians would be involved in risk assessment - they would not know where to start.

Chris

I dont know your experience in this part of healthcare design but I have given a specific example where clinicians would comment on this.

I think you are thinking about a general medical or surgical ward which is not the scenario i am discussing. Remember the regulations have to cover all areas.

Paul

I think anyone breaking into the mains wiring to create an arc to light a cigarette, deserves for the power to go off !!

A hand held rechargeable electric lighter should not be capable of tripping an AFD If it does the AFDD is not fit for purpose.

There are medical surgery machines that use similar arcs to cut and seal flesh - as an electric knife if you like,  but their EMC performance is carefully controlled.

Mike.

Hi Mike

The example I quoted is a very specific instance  and is not breaking into a wiring system - they create a fault L-N at the socket-outlet becaue they know an RCD will trip and it usually involves silver paper (or similar) in conjunction with alcohol gel. Yes - in this instance the desire is for it to trip!

 I dont know about plug in devices tripping or not tripping.

Finally, in terms of medical equipment that should not be an issue because there inormally no galvanic connection between in and the output and as you point out EMC performance is controlled to align with the BSEN 60601 series of documents. 

Paul