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Groups > sci.electronics.design > #461639 > unrolled thread
| Started by | RBlack <news@rblack01.plus.com> |
|---|---|
| First post | 2017-05-25 13:05 +0100 |
| Last post | 2017-05-31 09:37 -0700 |
| Articles | 20 on this page of 88 — 25 participants |
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Medical devices and US 220V electrics RBlack <news@rblack01.plus.com> - 2017-05-25 13:05 +0100
Re: Medical devices and US 220V electrics Winfield Hill <hill@rowland.harvard.edu> - 2017-05-25 05:55 -0700
Re: Medical devices and US 220V electrics upsidedown@downunder.com - 2017-05-25 17:26 +0300
Re: Medical devices and US 220V electrics Phil Hobbs <pcdhSpamMeSenseless@electrooptical.net> - 2017-05-25 10:27 -0400
Re: Medical devices and US 220V electrics George Herold <gherold@teachspin.com> - 2017-05-25 08:39 -0700
Re: Medical devices and US 220V electrics krw@notreal.com - 2017-05-25 12:40 -0400
Re: Medical devices and US 220V electrics Jan Panteltje <pNa0nStpealmtje@yahoo.com> - 2017-05-25 15:03 +0000
Re: Medical devices and US 220V electrics upsidedown@downunder.com - 2017-05-25 20:09 +0300
Re: Medical devices and US 220V electrics RBlack <news@rblack01.plus.com> - 2017-05-25 16:56 +0100
Re: Medical devices and US 220V electrics Jan Panteltje <pNa0nStpealmtje@yahoo.com> - 2017-05-25 16:42 +0000
Re: Medical devices and US 220V electrics upsidedown@downunder.com - 2017-05-25 20:38 +0300
Re: Medical devices and US 220V electrics whit3rd <whit3rd@gmail.com> - 2017-05-25 10:48 -0700
Re: Medical devices and US 220V electrics Neon John <no@never.com> - 2017-05-28 15:48 -0400
Re: Medical devices and US 220V electrics rickman <gnuarm@gmail.com> - 2017-05-29 01:08 -0400
Re: Medical devices and US 220V electrics Cursitor Doom <curd@notformail.com> - 2017-05-25 17:51 +0000
Re: Medical devices and US 220V electrics upsidedown@downunder.com - 2017-05-25 21:25 +0300
Re: Medical devices and US 220V electrics "Tom Del Rosso" <fizzbintuesday@that-google-mail-domain.com> - 2017-05-26 11:55 -0400
Re: Medical devices and US 220V electrics krw@notreal.com - 2017-05-26 17:38 -0400
Re: Medical devices and US 220V electrics "Tom Del Rosso" <fizzbintuesday@that-google-mail-domain.com> - 2017-05-26 20:32 -0400
Re: Medical devices and US 220V electrics krw@notreal.com - 2017-05-26 22:20 -0400
Re: Medical devices and US 220V electrics "Tom Del Rosso" <fizzbintuesday@that-google-mail-domain.com> - 2017-05-27 00:33 -0400
Re: Medical devices and US 220V electrics krw@notreal.com - 2017-05-27 09:37 -0400
Re: Medical devices and US 220V electrics legg <legg@nospam.magma.ca> - 2017-05-25 12:07 -0400
Re: Medical devices and US 220V electrics krw@notreal.com - 2017-05-25 12:49 -0400
Re: Medical devices and US 220V electrics Neon John <no@never.com> - 2017-05-28 15:56 -0400
Re: Medical devices and US 220V electrics krw@notreal.com - 2017-05-28 16:59 -0400
Re: Medical devices and US 220V electrics upsidedown@downunder.com - 2017-05-30 12:37 +0300
Re: Medical devices and US 220V electrics krw@notreal.com - 2017-05-30 17:41 -0400
Re: Medical devices and US 220V electrics gregz <zekor@comcast.net> - 2017-05-30 06:58 +0000
Re: Medical devices and US 220V electrics rickman <gnuarm@gmail.com> - 2017-05-25 12:15 -0400
Re: Medical devices and US 220V electrics Jon Elson <jmelson@wustl.edu> - 2017-05-25 15:07 -0500
Re: Medical devices and US 220V electrics John Larkin <jjlarkin@highland_snip_technology.com> - 2017-05-25 13:14 -0700
Re: Medical devices and US 220V electrics Jon Elson <jmelson@wustl.edu> - 2017-05-25 16:34 -0500
Re: Medical devices and US 220V electrics krw@notreal.com - 2017-05-25 18:47 -0400
Re: Medical devices and US 220V electrics Sjouke Burry <burrynulnulfour@ppllaanneett.nnll> - 2017-05-27 01:46 +0200
Re: Medical devices and US 220V electrics krw@notreal.com - 2017-05-26 19:53 -0400
Re: Medical devices and US 220V electrics Sjouke Burry <burrynulnulfour@ppllaanneett.nnll> - 2017-05-27 02:05 +0200
Re: Medical devices and US 220V electrics krw@notreal.com - 2017-05-26 22:21 -0400
Re: Medical devices and US 220V electrics Sjouke Burry <burrynulnulfour@ppllaanneett.nnll> - 2017-05-27 04:25 +0200
Re: Medical devices and US 220V electrics krw@notreal.com - 2017-05-26 22:33 -0400
Re: Medical devices and US 220V electrics Sjouke Burry <burrynulnulfour@ppllaanneett.nnll> - 2017-05-27 21:48 +0200
Re: Medical devices and US 220V electrics Don Y <blockedofcourse@foo.invalid> - 2017-05-25 11:20 -0700
Re: Medical devices and US 220V electrics Jon Elson <jmelson@wustl.edu> - 2017-05-25 14:57 -0500
Re: Medical devices and US 220V electrics RBlack <news@rblack01.plus.com> - 2017-05-26 12:17 +0100
Re: Medical devices and US 220V electrics tabbypurr@gmail.com - 2017-05-26 04:53 -0700
Re: Medical devices and US 220V electrics Phil Allison <pallison49@gmail.com> - 2017-05-26 06:00 -0700
Re: Medical devices and US 220V electrics rickman <gnuarm@gmail.com> - 2017-05-26 12:05 -0400
Re: Medical devices and US 220V electrics krw@notreal.com - 2017-05-26 17:51 -0400
Re: Medical devices and US 220V electrics George Herold <gherold@teachspin.com> - 2017-05-26 17:54 -0700
Re: Medical devices and US 220V electrics krw@notreal.com - 2017-05-26 22:24 -0400
Re: Medical devices and US 220V electrics upsidedown@downunder.com - 2017-05-27 00:52 +0300
Re: Medical devices and US 220V electrics Lasse Langwadt Christensen <langwadt@fonz.dk> - 2017-05-26 15:39 -0700
Re: Medical devices and US 220V electrics Neon John <no@never.com> - 2017-05-28 16:34 -0400
Re: Medical devices and US 220V electrics krw@notreal.com - 2017-05-28 17:26 -0400
Re: Medical devices and US 220V electrics Neon John <no@never.com> - 2017-05-29 12:12 -0400
Re: Medical devices and US 220V electrics krw@notreal.com - 2017-05-29 14:26 -0400
Re: Medical devices and US 220V electrics Tim Wescott <tim@seemywebsite.really> - 2017-05-29 00:08 -0500
Re: Medical devices and US 220V electrics David Lesher <wb8foz@panix.com> - 2017-05-29 20:24 +0000
Re: Medical devices and US 220V electrics krw@notreal.com - 2017-05-29 16:37 -0400
Re: Medical devices and US 220V electrics David Lesher <wb8foz@panix.com> - 2017-05-30 16:33 +0000
Re: Medical devices and US 220V electrics Jim Thompson <To-Email-Use-The-Envelope-Icon@On-My-Web-Site.com> - 2017-05-30 09:46 -0700
Re: Medical devices and US 220V electrics krw@notreal.com - 2017-05-30 17:45 -0400
Re: Medical devices and US 220V electrics David Lesher <wb8foz@panix.com> - 2017-05-31 03:31 +0000
Re: Medical devices and US 220V electrics krw@notreal.com - 2017-05-31 17:58 -0400
Re: Medical devices and US 220V electrics Jan Panteltje <pNa0nStpealmtje@yahoo.com> - 2017-06-01 07:54 +0000
Re: Medical devices and US 220V electrics upsidedown@downunder.com - 2017-06-01 12:49 +0300
Re: Medical devices and US 220V electrics Neon John <no@never.com> - 2017-06-01 10:28 -0400
Re: Medical devices and US 220V electrics Jan Panteltje <pNa0nStpealmtje@yahoo.com> - 2017-06-01 14:45 +0000
Re: Medical devices and US 220V electrics Neon John <no@never.com> - 2017-06-01 18:47 -0400
Re: Medical devices and US 220V electrics Lasse Langwadt Christensen <langwadt@fonz.dk> - 2017-06-01 15:57 -0700
Re: Medical devices and US 220V electrics Jan Panteltje <pNa0nStpealmtje@yahoo.com> - 2017-06-02 07:21 +0000
Re: Medical devices and US 220V electrics krw@notreal.com - 2017-06-01 18:59 -0400
Re: Medical devices and US 220V electrics David Lesher <wb8foz@panix.com> - 2017-06-03 14:00 +0000
Re: Medical devices and US 220V electrics krw@notreal.com - 2017-06-03 11:19 -0400
Re: Medical devices and US 220V electrics upsidedown@downunder.com - 2017-05-30 01:16 +0300
Re: Medical devices and US 220V electrics tabbypurr@gmail.com - 2017-05-29 22:31 -0700
Re: Medical devices and US 220V electrics Phil Allison <pallison49@gmail.com> - 2017-05-29 23:06 -0700
Re: Medical devices and US 220V electrics tabbypurr@gmail.com - 2017-05-29 23:25 -0700
Re: Medical devices and US 220V electrics Phil Allison <pallison49@gmail.com> - 2017-05-29 23:39 -0700
Re: Medical devices and US 220V electrics tabbypurr@gmail.com - 2017-05-30 00:19 -0700
Re: Medical devices and US 220V electrics rickman <gnuarm@gmail.com> - 2017-05-30 10:40 -0400
Re: Medical devices and US 220V electrics rickman <gnuarm@gmail.com> - 2017-05-30 10:37 -0400
Re: Medical devices and US 220V electrics Jim Thompson <To-Email-Use-The-Envelope-Icon@On-My-Web-Site.com> - 2017-05-30 16:58 -0700
Re: Medical devices and US 220V electrics Don Y <blockedofcourse@foo.invalid> - 2017-05-30 22:15 -0700
Re: Medical devices and US 220V electrics Jim Thompson <To-Email-Use-The-Envelope-Icon@On-My-Web-Site.com> - 2017-05-31 07:38 -0700
Re: Medical devices and US 220V electrics Don Kuenz <g@crcomp.net> - 2017-05-31 14:05 +0000
Re: Medical devices and US 220V electrics Jim Thompson <To-Email-Use-The-Envelope-Icon@On-My-Web-Site.com> - 2017-05-31 07:40 -0700
Re: Medical devices and US 220V electrics Don Y <blockedofcourse@foo.invalid> - 2017-05-31 09:37 -0700
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| From | "Tom Del Rosso" <fizzbintuesday@that-google-mail-domain.com> |
|---|---|
| Date | 2017-05-27 00:33 -0400 |
| Message-ID | <ogavie$105a$1@gioia.aioe.org> |
| In reply to | #461941 |
krw@notreal.com wrote: > On Fri, 26 May 2017 20:32:30 -0400, "Tom Del Rosso" > <fizzbintuesday@that-google-mail-domain.com> wrote: > >> krw@notreal.com wrote: >>> On Fri, 26 May 2017 11:55:33 -0400, "Tom Del Rosso" >>> <fizzbintuesday@that-google-mail-domain.com> wrote: >>> >>>> 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. >>>> >>>> When installing a new oven in an old kitchen it's not unusual to >>>> install a new circuit. Surely hospitals buying very big expensive >>>> equipment can have a new circuit installed. >>> >>> Huh? In a *very* old kitchen, maybe. In a house that old, likely >>> the entire house needs to be rewired. >> >> No. If the house is only a few decades old it probably wouldn't have >> enough in the kitchen for a fridge and a self-cleaning gas oven. >> > Fridges run on 120V. Self-cleaning *GAS* ovens don't take much > electricity at all (electric ones don't either). If you're switching > from gas to electricity, sure, but what nut does that? The self-cleaning gas ovens I've seen use electric elements for cleaning and modern codes around here require a separate circuit for it. A microwave adds another 10 amps, so kitchen renovations often require adding a couple of circuits. Just changing the oven could require one new circuit and the OP's product is probably a lot more expensive than a range.
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| From | krw@notreal.com |
|---|---|
| Date | 2017-05-27 09:37 -0400 |
| Message-ID | <940jicl5ten9rleniu9h06pomafs8l4j30@4ax.com> |
| In reply to | #461954 |
On Sat, 27 May 2017 00:33:18 -0400, "Tom Del Rosso" <fizzbintuesday@that-google-mail-domain.com> wrote: >krw@notreal.com wrote: >> On Fri, 26 May 2017 20:32:30 -0400, "Tom Del Rosso" >> <fizzbintuesday@that-google-mail-domain.com> wrote: >> >>> krw@notreal.com wrote: >>>> On Fri, 26 May 2017 11:55:33 -0400, "Tom Del Rosso" >>>> <fizzbintuesday@that-google-mail-domain.com> wrote: >>>> >>>>> 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. >>>>> >>>>> When installing a new oven in an old kitchen it's not unusual to >>>>> install a new circuit. Surely hospitals buying very big expensive >>>>> equipment can have a new circuit installed. >>>> >>>> Huh? In a *very* old kitchen, maybe. In a house that old, likely >>>> the entire house needs to be rewired. >>> >>> No. If the house is only a few decades old it probably wouldn't have >>> enough in the kitchen for a fridge and a self-cleaning gas oven. >>> >> Fridges run on 120V. Self-cleaning *GAS* ovens don't take much >> electricity at all (electric ones don't either). If you're switching >> from gas to electricity, sure, but what nut does that? > >The self-cleaning gas ovens I've seen use electric elements for cleaning >and modern codes around here require a separate circuit for it. A >microwave adds another 10 amps, so kitchen renovations often require >adding a couple of circuits. Just changing the oven could require one >new circuit and the OP's product is probably a lot more expensive than a >range. The point is that adding new circuits to existing homes is usually a *big* deal (tearing up many walls to run wiring) and is rarely done, unless the entire kitchen is being remodeled. Then, all circuits must be brought up to current code. Replacing an electric range with another electric range is no big deal. New ones, even self-cleaning, don't take any more power than those from fifty years ago.
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| From | legg <legg@nospam.magma.ca> |
|---|---|
| Date | 2017-05-25 12:07 -0400 |
| Message-ID | <m7vdichtn4d8039urkung7btpvo0377u3j@4ax.com> |
| In reply to | #461639 |
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........
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| From | krw@notreal.com |
|---|---|
| Date | 2017-05-25 12:49 -0400 |
| Message-ID | <ca2eicti29v41v6dl8td40e2cn5125bkgq@4ax.com> |
| In reply to | #461674 |
On Thu, 25 May 2017 12:07:59 -0400, legg <legg@nospam.magma.ca> wrote: >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. You're describing split-phase 240V; two 120V circuits split from a 240V circuit (by the center tap of a transformer). 208V is the voltage across two phases of a three phase 120V circuit, often used in commercial lighting but not used in residential settings at all. >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........
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| From | Neon John <no@never.com> |
|---|---|
| Date | 2017-05-28 15:56 -0400 |
| Message-ID | <miamichid098rv9v60stf9q0mskhb60tlf@4ax.com> |
| In reply to | #461682 |
On Thu, 25 May 2017 12:49:40 -0400, krw@notreal.com wrote: >>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. 120/208 is common only in large apartment building in places like NYC. IT is the bane of the residents who frequently have to resort to 208/240 boost autotransformers to get appliances like ACs and stoves to work properly. > >You're describing split-phase 240V; two 120V circuits split from a >240V circuit (by the center tap of a transformer). 208V is the >voltage across two phases of a three phase 120V circuit, often used in >commercial lighting but not used in residential settings at all. Sure it is. His device should be able to function from about 200 volts to 250 volts. >>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. Ever seen a portable X-ray machine? John John DeArmond http://www.neon-john.com http://www.tnduction.com Tellico Plains, Occupied TN See website for email address
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| From | krw@notreal.com |
|---|---|
| Date | 2017-05-28 16:59 -0400 |
| Message-ID | <peemic1ejn14q68c3r47m57cdj1ikgfsr5@4ax.com> |
| In reply to | #462107 |
On Sun, 28 May 2017 15:56:47 -0400, Neon John <no@never.com> wrote: >On Thu, 25 May 2017 12:49:40 -0400, krw@notreal.com wrote: > > >>>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. > >120/208 is common only in large apartment building in places like NYC. >IT is the bane of the residents who frequently have to resort to >208/240 boost autotransformers to get appliances like ACs and stoves >to work properly. > >> >>You're describing split-phase 240V; two 120V circuits split from a >>240V circuit (by the center tap of a transformer). 208V is the >>voltage across two phases of a three phase 120V circuit, often used in >>commercial lighting but not used in residential settings at all. > >Sure it is. His device should be able to function from about 200 >volts to 250 volts. No it is certainly *not*. Don't be an ass. >>>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. > >Ever seen a portable X-ray machine? As I said...
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| From | upsidedown@downunder.com |
|---|---|
| Date | 2017-05-30 12:37 +0300 |
| Message-ID | <a9eqiclvahn8aqlpjm4ts7hfmqufmkqqes@4ax.com> |
| In reply to | #461682 |
On Thu, 25 May 2017 12:49:40 -0400, krw@notreal.com wrote: >On Thu, 25 May 2017 12:07:59 -0400, legg <legg@nospam.magma.ca> wrote: > >>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. > >You're describing split-phase 240V; two 120V circuits split from a >240V circuit (by the center tap of a transformer). 208V is the >voltage across two phases of a three phase 120V circuit, often used in >commercial lighting but not used in residential settings at all. If you have 208 V, there must be a full 120/208 V three phase feed nearby. To the OP, when 3 phase is available, why not use a full 3 phase (6 pulse) rectifier. It just requires two extra diodes compared to a full wave single phase rectifier. When split phase 240 V is available, only 4 rectifiers work, but with three phase 120/208 V all 6 rectifiers are working. The rectified DC voltage is similar. In Europe with 230 V 16 A would give similar DC voltages. A 3x16 A 230/400 V feed would give considerably higher DC voltages. Thus, the device power supply should be built as an ordinary three phase 6 pulse rectifier with a storage capacitor (for single phase). A 3-phase mains connector on the device and all you need to wire the mains cable for 120/208 V, 2x120 V, 230 V (or possibly 230/400 V) with no switching needed in the device.
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| From | krw@notreal.com |
|---|---|
| Date | 2017-05-30 17:41 -0400 |
| Message-ID | <fkpricdtvsqr55ame6227gfpra970rbsfj@4ax.com> |
| In reply to | #462276 |
On Tue, 30 May 2017 12:37:41 +0300, upsidedown@downunder.com wrote: >On Thu, 25 May 2017 12:49:40 -0400, krw@notreal.com wrote: > >>On Thu, 25 May 2017 12:07:59 -0400, legg <legg@nospam.magma.ca> wrote: >> >>>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. >> >>You're describing split-phase 240V; two 120V circuits split from a >>240V circuit (by the center tap of a transformer). 208V is the >>voltage across two phases of a three phase 120V circuit, often used in >>commercial lighting but not used in residential settings at all. > >If you have 208 V, there must be a full 120/208 V three phase feed >nearby. If you have 240V (or 120V) you also have three phase feed nearby. There is nothing that says you have all three (of the phases), in any of the above cases.
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| From | gregz <zekor@comcast.net> |
|---|---|
| Date | 2017-05-30 06:58 +0000 |
| Message-ID | <261373338517820847.943037zekor-comcast.net@news.eternal-september.org> |
| In reply to | #461674 |
legg <legg@nospam.magma.ca> wrote: > 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........ 208 might be more common in hospitals. 240 in homes. Greg
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| From | rickman <gnuarm@gmail.com> |
|---|---|
| Date | 2017-05-25 12:15 -0400 |
| Message-ID | <og6vpb$nad$1@dont-email.me> |
| In reply to | #461639 |
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
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| From | Jon Elson <jmelson@wustl.edu> |
|---|---|
| Date | 2017-05-25 15:07 -0500 |
| Message-ID | <vJKdnRqqH4lTpbrEnZ2dnUU7-cXNnZ2d@giganews.com> |
| In reply to | #461675 |
rickman wrote: > No, 220 VAC is not common in the US, at least not in homes or offices. > I don't know what hospitals might have. Actually, 120/208 Wye service is quite common in larger offices. Might not have it in the typical storefront-type building, but almost any multi-level office building will likely have that system. It gives lots of 120 V single-phase outlets, and 208 V between any two hots. Smaller air conditioners would have 3-phase compressors off the 208 mains. The building I work in has 120/208 Wye in the offices, 120/208 Wye PLUS 230 Delta in the lab space and 480 in the mechanical areas. 3 Phase is VERY rare in single-family homes, but common in apartment buildings. And, certainly, any hospital will have 3-phase panels throughout the building. Jon
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| From | John Larkin <jjlarkin@highland_snip_technology.com> |
|---|---|
| Date | 2017-05-25 13:14 -0700 |
| Message-ID | <4geeicda411uf4rh5vu8b2hb8k65uk7ufa@4ax.com> |
| In reply to | #461718 |
On Thu, 25 May 2017 15:07:13 -0500, Jon Elson <jmelson@wustl.edu> wrote: >rickman wrote: > >> No, 220 VAC is not common in the US, at least not in homes or offices. >> I don't know what hospitals might have. > >Actually, 120/208 Wye service is quite common in larger offices. We have 120/240 3-phase, which is called a "stinger" service. That's 3-phase 240 line-to-line, with neutral being the center tap of one side of the triangle. https://en.wikipedia.org/wiki/High-leg_delta I suspect that any hospital could furnish 220 or 240 if equipment needs it. -- John Larkin Highland Technology, Inc picosecond timing precision measurement jlarkin att highlandtechnology dott com http://www.highlandtechnology.com
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| From | Jon Elson <jmelson@wustl.edu> |
|---|---|
| Date | 2017-05-25 16:34 -0500 |
| Message-ID | <SM-dnXiPysrZ0LrEnZ2dnUU7-KfNnZ2d@giganews.com> |
| In reply to | #461720 |
John Larkin wrote: > On Thu, 25 May 2017 15:07:13 -0500, Jon Elson <jmelson@wustl.edu> > wrote: > >>rickman wrote: >> >>> No, 220 VAC is not common in the US, at least not in homes or offices. >>> I don't know what hospitals might have. >> >>Actually, 120/208 Wye service is quite common in larger offices. > > We have 120/240 3-phase, which is called a "stinger" service. That's > 3-phase 240 line-to-line, with neutral being the center tap of one > side of the triangle. > Yes, there are legacy corner-grounded Delta and center-grounded Delta systems. These are not balanced around the center of the 3-phase system. Corner-grounded Delta systems generally use 2-pole breakers, as the 3rd leg of the 3-phases is at ground. What Rick refers to above is a center- grounded Delta, which allows you to have both 120 and 240 just like in residential service in the US, but also 3-phase 240 V power, all in one breaker panel, if you like. Commonly used in shops year ago, so you could supply all typical loads from one service. I'm pretty sure you can't get either of these types of service installed today. Jon
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| From | krw@notreal.com |
|---|---|
| Date | 2017-05-25 18:47 -0400 |
| Message-ID | <mkneic5tm98fgqulm9lg6euvg98q8g3987@4ax.com> |
| In reply to | #461718 |
On Thu, 25 May 2017 15:07:13 -0500, Jon Elson <jmelson@wustl.edu> wrote: >rickman wrote: > >> No, 220 VAC is not common in the US, at least not in homes or offices. >> I don't know what hospitals might have. > >Actually, 120/208 Wye service is quite common in larger offices. Might not >have it in the typical storefront-type building, but almost any multi-level >office building will likely have that system. It gives lots of 120 V >single-phase outlets, and 208 V between any two hots. Smaller air >conditioners would have 3-phase compressors off the 208 mains. The building >I work in has 120/208 Wye in the offices, 120/208 Wye PLUS 230 Delta in the >lab space and 480 in the mechanical areas. > >3 Phase is VERY rare in single-family homes, but common in apartment >buildings. And, certainly, any hospital will have 3-phase panels throughout >the building. 3-Phase will certainly be common in large apartment buildings but it'll never be found inside a single apartment. Think of the building as a neighborhood. ;-)
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| From | Sjouke Burry <burrynulnulfour@ppllaanneett.nnll> |
|---|---|
| Date | 2017-05-27 01:46 +0200 |
| Message-ID | <5928bed3$0$1714$e4fe514c@textnews.kpn.nl> |
| In reply to | #461738 |
On 26.05.17 0:47, krw@notreal.com wrote: > On Thu, 25 May 2017 15:07:13 -0500, Jon Elson <jmelson@wustl.edu> > wrote: > >> rickman wrote: >> >>> No, 220 VAC is not common in the US, at least not in homes or offices. >>> I don't know what hospitals might have. >> >> Actually, 120/208 Wye service is quite common in larger offices. Might not >> have it in the typical storefront-type building, but almost any multi-level >> office building will likely have that system. It gives lots of 120 V >> single-phase outlets, and 208 V between any two hots. Smaller air >> conditioners would have 3-phase compressors off the 208 mains. The building >> I work in has 120/208 Wye in the offices, 120/208 Wye PLUS 230 Delta in the >> lab space and 480 in the mechanical areas. >> >> 3 Phase is VERY rare in single-family homes, but common in apartment >> buildings. And, certainly, any hospital will have 3-phase panels throughout >> the building. > > 3-Phase will certainly be common in large apartment buildings but > it'll never be found inside a single apartment. Think of the building > as a neighborhood. ;-) > Hmm... I have a 220/380 3 phase cable feeding into my house, although I use only one of them.(In the dim past each house got current from 1 of those 3 wires)
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| From | krw@notreal.com |
|---|---|
| Date | 2017-05-26 19:53 -0400 |
| Message-ID | <0ufhicllg893ue3gqsgf13q31p92ark592@4ax.com> |
| In reply to | #461913 |
On Sat, 27 May 2017 01:46:41 +0200, Sjouke Burry <burrynulnulfour@ppllaanneett.nnll> wrote: >On 26.05.17 0:47, krw@notreal.com wrote: >> On Thu, 25 May 2017 15:07:13 -0500, Jon Elson <jmelson@wustl.edu> >> wrote: >> >>> rickman wrote: >>> >>>> No, 220 VAC is not common in the US, at least not in homes or offices. >>>> I don't know what hospitals might have. >>> >>> Actually, 120/208 Wye service is quite common in larger offices. Might not >>> have it in the typical storefront-type building, but almost any multi-level >>> office building will likely have that system. It gives lots of 120 V >>> single-phase outlets, and 208 V between any two hots. Smaller air >>> conditioners would have 3-phase compressors off the 208 mains. The building >>> I work in has 120/208 Wye in the offices, 120/208 Wye PLUS 230 Delta in the >>> lab space and 480 in the mechanical areas. >>> >>> 3 Phase is VERY rare in single-family homes, but common in apartment >>> buildings. And, certainly, any hospital will have 3-phase panels throughout >>> the building. >> >> 3-Phase will certainly be common in large apartment buildings but >> it'll never be found inside a single apartment. Think of the building >> as a neighborhood. ;-) >> >Hmm... I have a 220/380 3 phase cable feeding into my house, although I >use only one of them.(In the dim past each house got current from >1 of those 3 wires) My house? Each house? Please explain.
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| From | Sjouke Burry <burrynulnulfour@ppllaanneett.nnll> |
|---|---|
| Date | 2017-05-27 02:05 +0200 |
| Message-ID | <5928c337$0$1802$e4fe514c@textnews.kpn.nl> |
| In reply to | #461914 |
On 27.05.17 1:53, krw@notreal.com wrote: > On Sat, 27 May 2017 01:46:41 +0200, Sjouke Burry > <burrynulnulfour@ppllaanneett.nnll> wrote: > >> On 26.05.17 0:47, krw@notreal.com wrote: >>> On Thu, 25 May 2017 15:07:13 -0500, Jon Elson <jmelson@wustl.edu> >>> wrote: >>> >>>> rickman wrote: >>>> >>>>> No, 220 VAC is not common in the US, at least not in homes or offices. >>>>> I don't know what hospitals might have. >>>> >>>> Actually, 120/208 Wye service is quite common in larger offices. Might not >>>> have it in the typical storefront-type building, but almost any multi-level >>>> office building will likely have that system. It gives lots of 120 V >>>> single-phase outlets, and 208 V between any two hots. Smaller air >>>> conditioners would have 3-phase compressors off the 208 mains. The building >>>> I work in has 120/208 Wye in the offices, 120/208 Wye PLUS 230 Delta in the >>>> lab space and 480 in the mechanical areas. >>>> >>>> 3 Phase is VERY rare in single-family homes, but common in apartment >>>> buildings. And, certainly, any hospital will have 3-phase panels throughout >>>> the building. >>> >>> 3-Phase will certainly be common in large apartment buildings but >>> it'll never be found inside a single apartment. Think of the building >>> as a neighborhood. ;-) >>> >> Hmm... I have a 220/380 3 phase cable feeding into my house, although I >> use only one of them.(In the dim past each house got current from >> 1 of those 3 wires) > > My house? Each house? Please explain. > 3 houses, mine is the middle one, and each phase feeding 1 house. That way, I end up with a 3phase power cable.
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| From | krw@notreal.com |
|---|---|
| Date | 2017-05-26 22:21 -0400 |
| Message-ID | <kkohict1m08d0orl48p52vh2akpj6l7nks@4ax.com> |
| In reply to | #461916 |
On Sat, 27 May 2017 02:05:24 +0200, Sjouke Burry <burrynulnulfour@ppllaanneett.nnll> wrote: >On 27.05.17 1:53, krw@notreal.com wrote: >> On Sat, 27 May 2017 01:46:41 +0200, Sjouke Burry >> <burrynulnulfour@ppllaanneett.nnll> wrote: >> >>> On 26.05.17 0:47, krw@notreal.com wrote: >>>> On Thu, 25 May 2017 15:07:13 -0500, Jon Elson <jmelson@wustl.edu> >>>> wrote: >>>> >>>>> rickman wrote: >>>>> >>>>>> No, 220 VAC is not common in the US, at least not in homes or offices. >>>>>> I don't know what hospitals might have. >>>>> >>>>> Actually, 120/208 Wye service is quite common in larger offices. Might not >>>>> have it in the typical storefront-type building, but almost any multi-level >>>>> office building will likely have that system. It gives lots of 120 V >>>>> single-phase outlets, and 208 V between any two hots. Smaller air >>>>> conditioners would have 3-phase compressors off the 208 mains. The building >>>>> I work in has 120/208 Wye in the offices, 120/208 Wye PLUS 230 Delta in the >>>>> lab space and 480 in the mechanical areas. >>>>> >>>>> 3 Phase is VERY rare in single-family homes, but common in apartment >>>>> buildings. And, certainly, any hospital will have 3-phase panels throughout >>>>> the building. >>>> >>>> 3-Phase will certainly be common in large apartment buildings but >>>> it'll never be found inside a single apartment. Think of the building >>>> as a neighborhood. ;-) >>>> >>> Hmm... I have a 220/380 3 phase cable feeding into my house, although I >>> use only one of them.(In the dim past each house got current from >>> 1 of those 3 wires) >> >> My house? Each house? Please explain. >> >3 houses, mine is the middle one, and each phase feeding 1 house. >That way, I end up with a 3phase power cable. Why does the cable for the other two houses enter yours? Row houses?
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| From | Sjouke Burry <burrynulnulfour@ppllaanneett.nnll> |
|---|---|
| Date | 2017-05-27 04:25 +0200 |
| Message-ID | <5928e3ff$0$1680$e4fe514c@textnews.kpn.nl> |
| In reply to | #461942 |
On 27.05.17 4:21, krw@notreal.com wrote: > On Sat, 27 May 2017 02:05:24 +0200, Sjouke Burry > <burrynulnulfour@ppllaanneett.nnll> wrote: > >> On 27.05.17 1:53, krw@notreal.com wrote: >>> On Sat, 27 May 2017 01:46:41 +0200, Sjouke Burry >>> <burrynulnulfour@ppllaanneett.nnll> wrote: >>> >>>> On 26.05.17 0:47, krw@notreal.com wrote: >>>>> On Thu, 25 May 2017 15:07:13 -0500, Jon Elson <jmelson@wustl.edu> >>>>> wrote: >>>>> >>>>>> rickman wrote: >>>>>> >>>>>>> No, 220 VAC is not common in the US, at least not in homes or offices. >>>>>>> I don't know what hospitals might have. >>>>>> >>>>>> Actually, 120/208 Wye service is quite common in larger offices. Might not >>>>>> have it in the typical storefront-type building, but almost any multi-level >>>>>> office building will likely have that system. It gives lots of 120 V >>>>>> single-phase outlets, and 208 V between any two hots. Smaller air >>>>>> conditioners would have 3-phase compressors off the 208 mains. The building >>>>>> I work in has 120/208 Wye in the offices, 120/208 Wye PLUS 230 Delta in the >>>>>> lab space and 480 in the mechanical areas. >>>>>> >>>>>> 3 Phase is VERY rare in single-family homes, but common in apartment >>>>>> buildings. And, certainly, any hospital will have 3-phase panels throughout >>>>>> the building. >>>>> >>>>> 3-Phase will certainly be common in large apartment buildings but >>>>> it'll never be found inside a single apartment. Think of the building >>>>> as a neighborhood. ;-) >>>>> >>>> Hmm... I have a 220/380 3 phase cable feeding into my house, although I >>>> use only one of them.(In the dim past each house got current from >>>> 1 of those 3 wires) >>> >>> My house? Each house? Please explain. >>> >> 3 houses, mine is the middle one, and each phase feeding 1 house. >> That way, I end up with a 3phase power cable. > > Why does the cable for the other two houses enter yours? Row houses? > A row of 3. And why only one feed cable? I have no idea.
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| From | krw@notreal.com |
|---|---|
| Date | 2017-05-26 22:33 -0400 |
| Message-ID | <4aphic5qgdcirqmq1o3gjsnqurlnpl2g7n@4ax.com> |
| In reply to | #461944 |
On Sat, 27 May 2017 04:25:17 +0200, Sjouke Burry <burrynulnulfour@ppllaanneett.nnll> wrote: >On 27.05.17 4:21, krw@notreal.com wrote: >> On Sat, 27 May 2017 02:05:24 +0200, Sjouke Burry >> <burrynulnulfour@ppllaanneett.nnll> wrote: >> >>> On 27.05.17 1:53, krw@notreal.com wrote: >>>> On Sat, 27 May 2017 01:46:41 +0200, Sjouke Burry >>>> <burrynulnulfour@ppllaanneett.nnll> wrote: >>>> >>>>> On 26.05.17 0:47, krw@notreal.com wrote: >>>>>> On Thu, 25 May 2017 15:07:13 -0500, Jon Elson <jmelson@wustl.edu> >>>>>> wrote: >>>>>> >>>>>>> rickman wrote: >>>>>>> >>>>>>>> No, 220 VAC is not common in the US, at least not in homes or offices. >>>>>>>> I don't know what hospitals might have. >>>>>>> >>>>>>> Actually, 120/208 Wye service is quite common in larger offices. Might not >>>>>>> have it in the typical storefront-type building, but almost any multi-level >>>>>>> office building will likely have that system. It gives lots of 120 V >>>>>>> single-phase outlets, and 208 V between any two hots. Smaller air >>>>>>> conditioners would have 3-phase compressors off the 208 mains. The building >>>>>>> I work in has 120/208 Wye in the offices, 120/208 Wye PLUS 230 Delta in the >>>>>>> lab space and 480 in the mechanical areas. >>>>>>> >>>>>>> 3 Phase is VERY rare in single-family homes, but common in apartment >>>>>>> buildings. And, certainly, any hospital will have 3-phase panels throughout >>>>>>> the building. >>>>>> >>>>>> 3-Phase will certainly be common in large apartment buildings but >>>>>> it'll never be found inside a single apartment. Think of the building >>>>>> as a neighborhood. ;-) >>>>>> >>>>> Hmm... I have a 220/380 3 phase cable feeding into my house, although I >>>>> use only one of them.(In the dim past each house got current from >>>>> 1 of those 3 wires) >>>> >>>> My house? Each house? Please explain. >>>> >>> 3 houses, mine is the middle one, and each phase feeding 1 house. >>> That way, I end up with a 3phase power cable. >> >> Why does the cable for the other two houses enter yours? Row houses? >> >A row of 3. And why only one feed cable? I have no idea. OK, makes sense. I can see why they feed only one. The meters for all three units are on your wall, too, I suppose?
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