Japanese mains voltage minimum and maximum?

[treez]

Hello
Japan uses 100VAC mains, but do you know the min and max...is it +/-10%?

Wiki or google doesnt tell
https://en.wikipedia.org/wiki/Mains_electricity_by_country#Table_of_mains_voltages_and_frequencies

 

[treez]

Hello,
Is it possible that Japanese mains could be at 85VAC for extended periods of a few hours per day?

 

[D.A.(Tony)Stewart]

Hello,
Is it possible that Japanese mains could be at 85VAC for extended periods of a few hours per day?

The design must be compliant to 85Vac all day but may be at reduced output.

 

[FvM]

The Legrand Power Guide says the tolerance is +/- 6%.

 

[D.A.(Tony)Stewart]

iec 60064-1 gives guidelines but if seeking approval for export to,Japan JIC standards apply for no damage down to 85Vac which might be short term.

If you are concerned about oversaturation of core, from constant power load then LV protection is needed.

local regulations overide national which override international.

 

[treez]

The Legrand Power Guide says the tolerance is +/- 6%

Thanks, so this power supply, which can only support 92.5% of max load at 94VAC , is not suitable for 600W loads in Japan?, because it can only drive 0.925*624 = 577W?

PSU datasheet HRPG-600-48:
**broken link removed**

..And I would think that since the curve shown for dropout load vs VAC is at 60Hz, then dropout is even worse for 50Hz? (Japan has both 60Hz and 50Hz mains regions)

 

[D.A.(Tony)Stewart]

the load derates for this supply below 100Vac input by a linear amount

a drop of 15% input, results in a 20% drop in load limit
a drop of 6% input, results in 8% drop in load limit from 600W or a drop of 48W =552W @60Hz

and as you surmised worse @ 50Hz +\-10%

Check with supplier.

You mean well, there is no headroom or margin? Pun intended.

 

[treez]

thanks, so you're saying that the 50Hz Japanese mains has a worse tolerance (+/-10%) than the 60Hz Japanese mains (+/-6%)?

The document from FvM on page 21 just states 101V +/-6v, it doesn't state that the tolerance is worse at 50Hz than at 60Hz.?

Do you mean that the dropout of the HRPG-600-46 PSU will be worse at 50Hz, and you're saying that it will be down 10% from the 600W maximum? (I admit its actually 624W maximum)

 

[treez]

I am sure all would agree that the output power capability of an offline PSU would be worse at 50Hz mains than at 60Hz mains?

 

[FvM]

I am sure all would agree that the output power capability of an offline PSU would be worse at 50Hz mains than at 60Hz mains?

Possible but not certain. I would rely on manufacturer specifications rather than guesses.

 

[treez]

sorry ,my mistake, I was for some reason thinking of mains transformer (50hz) based supplies...of course, with an smps, it will have an up front pfc stage which wont care particularly whether its 50 or 60hz

 

[chuckey]

Well it will of course because the ripple across the main reservoir capacitor will increase by 20%. This could have some effect on the output voltage.
Frank

 

[FvM]

The "reservoir capacitor" is placed after the boost PFC stage, and it's voltage is kept constant independant of the mains input.

The ripple voltage does in fact increase from 60 to 50 Hz, but doesn't depend on the input voltage level. The PFC current limitation enforces however a power reduction with lower input voltage, as shown in Meanwell datasheet.

 

[treez]

Hello,
FvM's kindly supplied document tells that the Japanese mains is 101VAC +/-6v, the following document , on page A-9 says that its 100vac +/-10v
http://www.hyvac.com/tech_support/electrical_sources_worldwide.pdf
...and our senior engineer tells us that its 100vac +/-5v......


who do we believe?

If our PSU drops out at 90VAC but is ok at 94vac, then is it ok for use in Japan.?