SMT2200i Trim voltage

[BillP]

This question was originally posted by Gareth on APC forums on 2/2/2016

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Bringing this up as I am in the UK with the UPS at a fixed voltage of 240v, I cannot change this in the dropdown.

I have high mains input between 243-250v, I have trim set to kick in at 255v, 2 volts above 10% of the 230v that is now the UK standard.

 If trim kicks in it does so at 220 volts.

Can I change this to the correct preset input voltage of 240v?

And to those who would like to point me to the various web pages with console commands this series post dates the ability to login by Hyperterminal, it doesn't respond like the older units 😞

I  still  find  it hard to believe a £800 UPS thinks it is OK to drop the voltage by 35v when using trim?

Thanks.

[voidstar_apc · Accepted solution]

This was originally posted on APC forums on 2/3/2016

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Hi Gareth,

The technical specs for the SMT2200i says it supports 220, 230, and 240V. You probably need to turn the output off before you can change the output voltage (this is different from previous SmartUPSes).

If I understand you correctly, you've set the output upper limit to 255V. When the input voltage goes above this limit, the UPS trims the output down to 220V? 220 is within the UK standard of 230 +10% / -6%. Pragmatically power supplies aren't particularly picky about getting a little less voltage.

The reason you're not seeing 230V during trim is because the UPS' internal transformer trims in discrete steps (ie, 10%, 20%). Much more expensive and less energy efficient UPSes offer double-conversion which gives you exactly 230V independent of the input voltage.

If your input regularly exceeds 253V and needs trimming, I would contact your electricity supplier.

[BillP]

This reply was originally posted by Gareth on APC forums on 2/3/2016

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Thanks, I think it is time to log a fault with my supplier 🙂