UPS voltage settings

[Anonymous user]

Hi,

I have two SURT6000XLI ups with the following voltage configurations:

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- Output Voltage: 230vac

- Upper Bypass limit: 253vac

- Lower Bypass limit: 161vac

- Allowable Frequency range for UPS bypass: Auto sensing

- Power Quality Sensitivity: Automatic

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I can see that in the PowerChute Business Edition application that ihe input line voltage vary from 210vac to 228vac.

Since I am a total newbie to UPS power configuration, I need assistance to validate is this configuration (I assume factory default) is good enough to keep, or if it should be changed. The UPS's are currently supporting a bunch of Cisco networking equipment, HP storage and few HP servers.

Here is an example of what I have in my mind concerning a new configuration:

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- Output Voltage: 220vac

- Upper Bypass limit: 264vac

- Lower Bypass limit: 154vac

- Allowable Frequency range for UPS bypass: Auto sensing

- Power Quality Sensitivity: Automatic

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Can anyone see any issues or risks if going with this configuration?

Should I stick to the default configuration?

Any assistance will be much appreciated.

Kind regards,

Janko

[Anonymous user]

Hello, need some additional info before suggesting anything firm:

1. Are you having a problem with any transfers to battery caused by the input voltage swings ?   (... if not there isn't much reason to tweak the factory settings, really, as you aren't subjecting the UPS to unnecessary wear and tear and all your devices are in the protected range ).

2. Is the nominal UPS supply (Input) voltage supposed to be 230 volts ?   ( I see you are in Denmark so I am guessing the answer is yes... 230 V @ 50 Hz)

3. What is the input voltage range rating of the power supplies for your Cisco and HP hardware ?

....here in Canada our Cisco power supplies are usually able to accept  100 to 240 VAC range, for example, so if this is the same for your hardware I would not recommend changing your upper bypass setting any higher (eg to 264 volts) you risk blowing up the power supplies if  your UPS has a fault and goes into bypass.

[Anonymous user]

Hello Battman, many thanks for your input.

Here is some additional info.

1. There are no problem with trasfers to batteries and yes, I would prefer not to tweak with factory setting.

2. I am located in Angola where the nominal input voltage here is 220V@50Hz.

The challenge in this respect is that the local power lines are not reliable. There are daily outages.

Thus I have been thinking if it make sense to tweak 'Lower & Upper Voltage Bypass' limits.

3. All IT equipment have been until now connected to one of SURT6000XLI that delivers output voltage 230V@50Hz.

Which one of the following configurations makes most sense and are there any risks associated?

Tweek the factory settings according to the nominal power line conditions in Angola:

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- Nominal Input Voltage: 220vac

- UPS Output Voltage: 220vac

- Upper Bypass limit: 264vac

- Lower Bypass limit: 154vac

- Allowable Frequency range for UPS bypass: Auto sensing

- Power Quality Sensitivity: Automatic

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or keep the factory settings:

--------------------------------------------------------

- Nominal Input Voltage: 220vac

- UPS Output Voltage: 230vac

- Upper Bypass limit: 253vac

- Lower Bypass limit: 161vac

- Allowable Frequency range for UPS bypass: Auto sensing

- Power Quality Sensitivity: Automatic

--------------------------------------------------------

Thanks.

Regards,

Janko

[Anonymous user · Accepted solution]

The way it looks to me, I don't think there is a need to change the factory settings... you will not really have anything to gain by it. The upper and lower bypass settings don't come into play in power outage situations where the UPS is deciding whether to go to battery, but rather they apply in cases where the UPS has an internal fault or is overloaded and needs to go to bypass - in that situation based on the current settings if the incoming voltage is above 253 it will drop the loads instead of going to bypass to avoid damaging the loads. Changing the upper bypass to a higher value is in fact risky, as I mentioned before because the UPS will pass an even higher voltage ( IE higher than 253 ) to the loads if it has a fault and goes to bypass. Your current output voltage setting of 230 should be ok as your networking and server hardware should be good on inputs of up to 240 volts. If you have the option of lowering the output voltage to 220 to match the input that would be ok too.