Minor Rant

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itasca_mn

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Location
Minnesota
Yes, if. Clarification from the OP would be helpful.

I find this to be an issue with both single and 3-phase equipment. Every building on campus is fed with 3-phase, 4160 volts, and stepped down to 120/208, and in a few buildings, also 277/480. All have 3-phase panelboards and switchgear. The last piece of equipment installed with this issue, the Autoclave, requires 230-240 volts, single phase. The manufacturer insisted that the boost transformer be used for warranty issues.



I guess I can buy the fact that in the world market, the USA makes up just a fraction of their customers.
 

Besoeker3

Senior Member
Location
UK
Occupation
Retired Electrical Engineer
I find this to be an issue with both single and 3-phase equipment. Every building on campus is fed with 3-phase, 4160 volts, and stepped down to 120/208, and in a few buildings, also 277/480. All have 3-phase panelboards and switchgear. The last piece of equipment installed with this issue, the Autoclave, requires 230-240 volts, single phase. The manufacturer insisted that the boost transformer be used for warranty issues.



I guess I can buy the fact that in the world market, the USA makes up just a fraction of their customers.
Not a huge percentage of the entire world population but, as a capitalist country, a significant proportion of the world market.
Is the frequency (50/60 Hz) an issue for your Autoclave?
 

itasca_mn

Member
Location
Minnesota
Due to those doing the ordering/ specifying don't have a clue to what power is needed or available; then we do what we do to make it work. They rarely realize the steps they may or may not cause; if only they would ask before ordering.
That can be a large part of it, but in the case of this Autoclave, a 208 volt model that suited the science department's needs, could not be identified.
 

itasca_mn

Member
Location
Minnesota
Why do people keep ordering machines that don't match the supply voltage available?

With a quick search you can find equipment designed to operate on 3-phase 208V. It's not like they stopped manufacturing it.

You'd be surprised how much equipment out there has no 208 volt option available. Even some tools use 3-phase motors that are not listed for use on 208 volts. Jet is one manufacturer where this has been an issue in the past, and when talking to the distributor, warranty coverage can be questionable if operated on 208 volts.
 

kwired

Electron manager
Location
NE Nebraska
Interesting. Not many countries are 230V 60Hz. And no major economies that I'm aware of so why manufacture kit designed to run on that?
I would assume the majority of load is heating elements and won't care about frequency. Whatever other controls are present may not care about frequency as well. Which also leaves me wondering what it would hurt to run it on 208 volts other than a strict warranty policy or controls that for some reason won't operate correctly on 208? You get about 25% less watts from the heat elements, but have to presume they are oversized to some extent and won't really impact overall operation, just needs a little longer warm up time. As far as warranty goes, depends on value of the item and what it may need for repairs. If you are willing to eat cost in that first year or two if needed you possibly could still come out ahead compared to adding transformation to go from 208-240 or vice versa. After that warranty runs out you are eating repair cost anyway.
 

Besoeker3

Senior Member
Location
UK
Occupation
Retired Electrical Engineer
I would assume the majority of load is heating elements and won't care about frequency. Whatever other controls are present may not care about frequency as well. Which also leaves me wondering what it would hurt to run it on 208 volts other than a strict warranty policy or controls that for some reason won't operate correctly on 208? You get about 25% less watts from the heat elements, but have to presume they are oversized to some extent and won't really impact overall operation, just needs a little longer warm up time. As far as warranty goes, depends on value of the item and what it may need for repairs. If you are willing to eat cost in that first year or two if needed you possibly could still come out ahead compared to adding transformation to go from 208-240 or vice versa. After that warranty runs out you are eating repair cost anyway.
Yes, I get all that.
My point was why rate it for a system that is used hardly anywhere?
Doesn't seem to make sense.
What am I missing?
 

Besoeker3

Senior Member
Location
UK
Occupation
Retired Electrical Engineer
230 is the same as 240 for the world market.

Many 60Hz products made in America are labeled for the worldwide nominal of 230V.
But many are 50Hz.
EU, middle east, India, China, most of the African countries.....Australia..........
230V/60Hz is not that common.
 

itasca_mn

Member
Location
Minnesota
Yes, I get all that.
My point was why rate it for a system that is used hardly anywhere?
Doesn't seem to make sense.
What am I missing?

In the end it all comes down to the fact there is no 230-240 volts available anywhere on campus without using an additional transformer. This autoclave is a fairly sophisticated model that in addition to resistive heating elements, it contains a small computer, a printer, water pumps, electronic/electric door lock, and a fan.
 

mbrooke

Batteries Included
Location
United States
Occupation
Technician
I would assume the majority of load is heating elements and won't care about frequency. Whatever other controls are present may not care about frequency as well. Which also leaves me wondering what it would hurt to run it on 208 volts other than a strict warranty policy or controls that for some reason won't operate correctly on 208? You get about 25% less watts from the heat elements, but have to presume they are oversized to some extent and won't really impact overall operation, just needs a little longer warm up time. As far as warranty goes, depends on value of the item and what it may need for repairs. If you are willing to eat cost in that first year or two if needed you possibly could still come out ahead compared to adding transformation to go from 208-240 or vice versa. After that warranty runs out you are eating repair cost anyway.

I believe the issue is not one of voltage, but rather one of bandwidth. It is possible for 230 volt equipment to function without difference on a 208 volt supply, but it is also possible to have problems. The governing factor are the actual minimum voltages experienced.


There is a blessing in a favorable lottery however. In the US 120/208Y volt supplies usually come from well regulated utilities (-5%+5%) and are on average found to be within the middle to upper end of the spectrum. This is why so many 230 volt motors run fine in the US despite being perpetually fed at the low end of the tolerance spectrum. At the same time a lot of 230 volt equipment is generally (though not always) designed around (-10%+10%):

1. possibility of going into nominal legacy 220 volt countries like Russia or mainland Europe where the low end of the spectrum can actually be 198 volts.

2. UK has a nominal legacy voltage of 240 volts, and the upper end of 260 can still be found in places.

3. Through out most of the world LV networks are very vast, often one transformer can feed hundreds if not a thousand customers. As such its not unheard of to have +8% of nominal at the bushings with the anticipation of having -8% of 230 at the last service- big drop. In the US this is rare, a steady 122 volts is usually measured through out the year.



So when all is said and done, in many cases it won't be an issue.
 

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Besoeker3

Senior Member
Location
UK
Occupation
Retired Electrical Engineer
In the end it all comes down to the fact there is no 230-240 volts available anywhere on campus without using an additional transformer. This autoclave is a fairly sophisticated model that in addition to resistive heating elements, it contains a small computer, a printer, water pumps, electronic/electric door lock, and a fan.
That was kinda my point. Why make it 230V/60Hz? Where is their market?
 

MAC702

Senior Member
Location
Clark County, NV
But many are 50Hz.
EU, middle east, India, China, most of the African countries.....Australia..........
230V/60Hz is not that common.

You missed my point, as I wasn't clear enough what it was. The 50/60Hz is critical (for most applications) so the machine will be made for one or the other and reflect it on the label.

The machine has nothing different about it for whether it is intended for a market that is 220V actual, 230V actual, or 240V actual. Worldwide nominal for all of these is usually "230V" these days, and that's on the label.

My greatest experience in this regard is with Miller/Hobart welding machines, as I've been active on their forums for decades, and have been a Beta tester for two of their products in the last ten years. So I'm constantly using them, the product labels, literature, and helping people hook them up.

They all say 230V 60Hz on the label.

For additional example, many products in an American house these days probably say 115V, not 120V, even if made in America, and the Americas are the only places to use that voltage range, with a few exceptions.
 
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Besoeker3

Senior Member
Location
UK
Occupation
Retired Electrical Engineer
You missed my point, as I wasn't clear enough what it was. The 50/60Hz is critical (for most applications) so the machine will be made for one or the other and reflect it on the label.
With utmost respect, I think you missed mine.
A 230V/60 Hz supply is not very common so why design/manufacture kit for that?
 

itasca_mn

Member
Location
Minnesota
From my standpoint its more about whether I have a warranty if these machines crap out. Documentation states a voltage range above what we can supply.
 

GoldDigger

Moderator
Staff member
Location
Placerville, CA, USA
Occupation
Retired PV System Designer
FWIW, if the autoclave is part of a process that is time sensitive, then taking longer to reach operating temperature has an economic cost. And if the operating procedures are written in terms of time from start of batch, then a longer heating time could make those numbers incorrect, with possible safety consequences.

Sent from my XT1585 using Tapatalk
 
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