Forums

Medical devices and US 220V electrics

Started by RBlack May 25, 2017
Hi,

We are working on a medical product, which will draw about 3 kW from the 
mains.  This is new territory for us, all our previous products were a 
few hundred watts max so an off-the-shelf auto-ranging PSU with a 
suitable IEC lead was OK for any country in the world.

3 kW is OK for a standard outlet in 220V countries, but for North 
America, Japan etc we are over the limit for a standard 110V outlet.

I only know as much about US electrical installations as I've read, a 
bit of Googling suggests the product will need a NEMA 6-15 220V outlet.  
But how common are these in hospitals?  Anybody have any experience of 
this stuff?

It has been suggested (not by me I hasten to add) that we split the 
loads within the product up and give it two 110V inlets, to get around 
the customer having to install a 'special' outlet for it.  This sounds 
like a Really Bad Idea and a regulatory nightmare to me, so if 220V 
outlets are commonly available anyway I can shoot it down before it gets 
too far.

TIA
RBlack wrote...
> > We are working on a medical product, which will draw > about 3 kW from the mains.
You need to work really hard to get that down to 1.5kW. -- Thanks, - Win
On Thu, 25 May 2017 13:05:28 +0100, RBlack <news@rblack01.plus.com>
wrote:

>We are working on a medical product, which will draw about 3 kW from the >mains. This is new territory for us, all our previous products were a >few hundred watts max so an off-the-shelf auto-ranging PSU with a >suitable IEC lead was OK for any country in the world.
Is this peak or average ? Is it 3 kW or 3 kVA ? What power factor ?
>3 kW is OK for a standard outlet in 220V countries, but for North >America, Japan etc we are over the limit for a standard 110V outlet.
It is not OK for 220-240 V outlets with 10 A fuses. You would have to install a dedicated 16 A outlet. Any additional loads on the same fuse might eventually blow the fuse, a situation which is not appreciated in a hospital environment.
On 05/25/2017 10:26 AM, upsidedown@downunder.com wrote:
> On Thu, 25 May 2017 13:05:28 +0100, RBlack <news@rblack01.plus.com> > wrote: > >> We are working on a medical product, which will draw about 3 kW from the >> mains. This is new territory for us, all our previous products were a >> few hundred watts max so an off-the-shelf auto-ranging PSU with a >> suitable IEC lead was OK for any country in the world. > > Is this peak or average ? > Is it 3 kW or 3 kVA ? What power factor ? > >> 3 kW is OK for a standard outlet in 220V countries, but for North >> America, Japan etc we are over the limit for a standard 110V outlet. > > It is not OK for 220-240 V outlets with 10 A fuses. You would have to > install a dedicated 16 A outlet. > > Any additional loads on the same fuse might eventually blow the fuse, > a situation which is not appreciated in a hospital environment. >
Not to mention what it'll do to the room temperature. What is it, a defibrillator for whales? Cheers Phil Hobbs -- Dr Philip C D Hobbs Principal Consultant ElectroOptical Innovations LLC Optics, Electro-optics, Photonics, Analog Electronics 160 North State Road #203 Briarcliff Manor NY 10510 hobbs at electrooptical dot net http://electrooptical.net
On a sunny day (Thu, 25 May 2017 17:26:01 +0300) it happened
upsidedown@downunder.com wrote in
<gppdic1713mfpmmvv5466qgg74l8fr1k8r@4ax.com>:

>On Thu, 25 May 2017 13:05:28 +0100, RBlack <news@rblack01.plus.com> >wrote: > >>We are working on a medical product, which will draw about 3 kW from the >>mains. This is new territory for us, all our previous products were a >>few hundred watts max so an off-the-shelf auto-ranging PSU with a >>suitable IEC lead was OK for any country in the world. > >Is this peak or average ? >Is it 3 kW or 3 kVA ? What power factor ? > >>3 kW is OK for a standard outlet in 220V countries, but for North >>America, Japan etc we are over the limit for a standard 110V outlet. > >It is not OK for 220-240 V outlets with 10 A fuses. You would have to >install a dedicated 16 A outlet.
It is 230V here these days. You could 3 phase power. Then you can have smaller filter caps too ;-)
On Thursday, May 25, 2017 at 10:27:50 AM UTC-4, Phil Hobbs wrote:
> On 05/25/2017 10:26 AM, upsidedown@downunder.com wrote: > > On Thu, 25 May 2017 13:05:28 +0100, RBlack <news@rblack01.plus.com> > > wrote: > > > >> We are working on a medical product, which will draw about 3 kW from the > >> mains. This is new territory for us, all our previous products were a > >> few hundred watts max so an off-the-shelf auto-ranging PSU with a > >> suitable IEC lead was OK for any country in the world. > > > > Is this peak or average ? > > Is it 3 kW or 3 kVA ? What power factor ? > > > >> 3 kW is OK for a standard outlet in 220V countries, but for North > >> America, Japan etc we are over the limit for a standard 110V outlet. > > > > It is not OK for 220-240 V outlets with 10 A fuses. You would have to > > install a dedicated 16 A outlet. > > > > Any additional loads on the same fuse might eventually blow the fuse, > > a situation which is not appreciated in a hospital environment. > > > > Not to mention what it'll do to the room temperature. What is it, a > defibrillator for whales?
I'd welcome a little more heat in hospital rooms. I was in one a week or two ago, they keep those things too cold for my blood. George H.
> > Cheers > > Phil Hobbs > > -- > Dr Philip C D Hobbs > Principal Consultant > ElectroOptical Innovations LLC > Optics, Electro-optics, Photonics, Analog Electronics > > 160 North State Road #203 > Briarcliff Manor NY 10510 > > hobbs at electrooptical dot net > http://electrooptical.net
On Thu, 25 May 2017 17:26:01 +0300,  (upsidedown@downunder.com) said:
> On Thu, 25 May 2017 13:05:28 +0100, RBlack <news@rblack01.plus.com> > wrote: > > >We are working on a medical product, which will draw about 3 kW from the > >mains. This is new territory for us, all our previous products were a > >few hundred watts max so an off-the-shelf auto-ranging PSU with a > >suitable IEC lead was OK for any country in the world. > > Is this peak or average ? > Is it 3 kW or 3 kVA ? What power factor ? > > >3 kW is OK for a standard outlet in 220V countries, but for North > >America, Japan etc we are over the limit for a standard 110V outlet. > > It is not OK for 220-240 V outlets with 10 A fuses. You would have to > install a dedicated 16 A outlet. > > Any additional loads on the same fuse might eventually blow the fuse, > a situation which is not appreciated in a hospital environment. > >
The 3kW figure is peak, for maybe 15 minutes at a time. Average would be closer to a few hundred watts. Power factor should be close to unity, the loads are all either resistive or on the other side of a SMPS with active PFC. My preference, for all the reasons that have come up so far, would be a dedicated outlet, but the marketing guys are resisting this as they think it creates a potential obstacle to the buyer. I can't understand this myself, we just acquired an environmental chamber which needed its own 32A 3 phase outlet. The cost of installing that was a tiny fraction of the unit itself.
On Thu, 25 May 2017 13:05:28 +0100, RBlack <news@rblack01.plus.com>
wrote:

>Hi, > >We are working on a medical product, which will draw about 3 kW from the >mains. This is new territory for us, all our previous products were a >few hundred watts max so an off-the-shelf auto-ranging PSU with a >suitable IEC lead was OK for any country in the world. > >3 kW is OK for a standard outlet in 220V countries, but for North >America, Japan etc we are over the limit for a standard 110V outlet. > >I only know as much about US electrical installations as I've read, a >bit of Googling suggests the product will need a NEMA 6-15 220V outlet. >But how common are these in hospitals? Anybody have any experience of >this stuff? > >It has been suggested (not by me I hasten to add) that we split the >loads within the product up and give it two 110V inlets, to get around >the customer having to install a 'special' outlet for it. This sounds >like a Really Bad Idea and a regulatory nightmare to me, so if 220V >outlets are commonly available anyway I can shoot it down before it gets >too far. > >TIA
Split phase 208VAC is not uncommon in NA - used to be standard for Kitchen stove, laundry drier or workbench hookups. Up to 20A/phase using 4wire armoured or flex cabling to iether duplexed 2x15 or 2x20A 120V wall outlets or single 15/20A outlets. They need separate but coupled breakers on each line. If the power level you are talking about is already typically used in the application, then you should use the power couplers presently employed in the medical 'industry' for that application. Equipment with that type of power consumption are not normally considered to be either portable or transportable, so a power requirement isn't a big issue. It is not likely to be included in any situation that has patient-applied parts, either, so the 'medical' part of it's labeling is likely only there to avoid commercial restrictions on similar products, like EMC........
RBlack wrote on 5/25/2017 8:05 AM:
> Hi, > > We are working on a medical product, which will draw about 3 kW from the > mains. This is new territory for us, all our previous products were a > few hundred watts max so an off-the-shelf auto-ranging PSU with a > suitable IEC lead was OK for any country in the world. > > 3 kW is OK for a standard outlet in 220V countries, but for North > America, Japan etc we are over the limit for a standard 110V outlet. > > I only know as much about US electrical installations as I've read, a > bit of Googling suggests the product will need a NEMA 6-15 220V outlet. > But how common are these in hospitals? Anybody have any experience of > this stuff? > > It has been suggested (not by me I hasten to add) that we split the > loads within the product up and give it two 110V inlets, to get around > the customer having to install a 'special' outlet for it. This sounds > like a Really Bad Idea and a regulatory nightmare to me, so if 220V > outlets are commonly available anyway I can shoot it down before it gets > too far.
No, 220 VAC is not common in the US, at least not in homes or offices. I don't know what hospitals might have. If you are talking about installing this in a lab setting, then providing 220 VAC is not really an issue, but it likely will require adding an outlet rather than just plugging it in. All buildings have 220 VAC at the fuse panel, it is only distributed to the equipment that needs it like furnaces, clothes dryers and stoves. Office settings are often wired with both phases for the 110 VAC outlets with every other one on alternate phases. This helps to balance the load on the two phases. So there may well be 220 volts in a given outlet box, you just have to install a different outlet. In homes they only run three wires to each outlet box, AC, common and earth. So any 220 VAC outlets will require a new run unless your unit goes in next to a dryer or stove that can be off when your unit runs. I don't know code, but that is likely not allowed since running both could overload the circuit. The bottom line is 220 VAC outlets are not commonly available, but 220 VAC is available in all buildings if you want to run a line for a new outlet. -- Rick C
On Thu, 25 May 2017 08:39:27 -0700 (PDT), George Herold
<gherold@teachspin.com> wrote:

>On Thursday, May 25, 2017 at 10:27:50 AM UTC-4, Phil Hobbs wrote: >> On 05/25/2017 10:26 AM, upsidedown@downunder.com wrote: >> > On Thu, 25 May 2017 13:05:28 +0100, RBlack <news@rblack01.plus.com> >> > wrote: >> > >> >> We are working on a medical product, which will draw about 3 kW from the >> >> mains. This is new territory for us, all our previous products were a >> >> few hundred watts max so an off-the-shelf auto-ranging PSU with a >> >> suitable IEC lead was OK for any country in the world. >> > >> > Is this peak or average ? >> > Is it 3 kW or 3 kVA ? What power factor ? >> > >> >> 3 kW is OK for a standard outlet in 220V countries, but for North >> >> America, Japan etc we are over the limit for a standard 110V outlet. >> > >> > It is not OK for 220-240 V outlets with 10 A fuses. You would have to >> > install a dedicated 16 A outlet. >> > >> > Any additional loads on the same fuse might eventually blow the fuse, >> > a situation which is not appreciated in a hospital environment. >> > >> >> Not to mention what it'll do to the room temperature. What is it, a >> defibrillator for whales? >I'd welcome a little more heat in hospital rooms. I was in one a week >or two ago, they keep those things too cold for my blood.
That's why they invented blankets.