UTS10BI with UPS question

[Anonymous user]

I Installed the UTS last weekend and added a UPS last night.  Everything is working great, but I want to make sure I understand what the unit is doing.  After setting one circuit (#4) to "uninterruptible" I noticed that the circuit status showed the load on circuit 1 increased.  I think this makes sense as I believe the entire load of any circuits set to uninterruptible will go through the UPS all the time and the Ups is powered by circuit 1.  However, the load on circuit 4 (which was changed to uninterruptible) stayed at its original level.   If you check the system status total load, it also increased.  It appears this creates a "double counting" of the watts by continuing to report them on the individual circuits as well as adding the load to circuit 1.  So my questions are:

1) after changing #4 to uninterruptible, the load on that circuit stayed around 400 watts, and circuit 1 went up by around 400 watts.   Is this right?  Doesn't this over report power usage?

2) if all circuits set to uninterruptible draw their power through circuit 1, does that mean we must limit the total load to the capacity of the UPS?

3) does load shedding work the same way for uninterruptible circuits?  In other words, what happens when the total load across all uninterruptible circuits spikes above the capacity limit set for the UPS? 

4) when setting the power rating for backup2 (the UPS), I assume you set the rated wattage correct?   I have a 1350VA / 810 watt UPS, so I set the power rating to 810.  

5) what is the recommended settings for Surge Overload times for a ups?   I understand this determines how long the system will allow a spike above the power rating to continue before shedding loads, but I don't know what is appropriate for a UPS and I don't see anything to help in the UPS documentation.

6) last but not least, a non-UPS question:  what is the appropriate power level to enter for the generator?  The continuous power rating or the surge rating?  My generator is rated at 7000 continuous and 8750 peak. 

I thought I'd tap into the collective wisdom here before I drive my family nuts as I keep switching power on and off all over the house...

thank you!

jason

[BillP]

Hi Jason,

Please see my response in Blue;

1) after changing #4 to uninterruptible, the load on that circuit stayed around 400 watts, and circuit 1 went up by around 400 watts.   Is this right?  Doesn't this over report power usage?

I can understand your concern with the reporting. I would expect the load ON the circuit set to Uninterruptible to be present as it is refelcting the load being drawn through that specific circuit, even though the source of this power is coming through circuit 1. I agree, it does seem as if it may be caluculated twice. I will have to perform some testing to confirm.

2) if all circuits set to uninterruptible draw their power through circuit 1, does that mean we must limit the total load to the capacity of the UPS?

Any circuit set to uninterruptible should be limited to the overall capacity of the UPS.

3) does load shedding work the same way for uninterruptible circuits?  In other words, what happens when the total load across all uninterruptible circuits spikes above the capacity limit set for the UPS?

Load shedding would result in the UPS going to battery during this circuit downtime, continuing to power the uninterruptible load until power returns or the internal battery of the UPS is exhausted. If the load exceeds the UPS's capability, the UPS will enter an Overload conditon resulting in the uninterruptible load being turned off.

4) when setting the power rating for backup2 (the UPS), I assume you set the rated wattage correct?   I have a 1350VA / 810 watt UPS, so I set the power rating to 810. 

Correct

5) what is the recommended settings for Surge Overload times for a ups?   I understand this determines how long the system will allow a spike above the power rating to continue before shedding loads, but I don't know what is appropriate for a UPS and I don't see anything to help in the UPS documentation.

This should be set to ), as the UPS will respond as designed. This option is present incase the user would like to add a second single phase generator to the UPS inlet, 1-2k for example.

6) last but not least, a non-UPS question:  what is the appropriate power level to enter for the generator?  The continuous power rating or the surge rating?  My generator is rated at 7000 continuous and 8750 peak.

This is an interesting question. Considering the UTS has the ability to shed load as necessary to avoid overloading the generator, you could (in principle) set the generator rating to the peak. To be on the safe side however, I would recommend setting for the 7k continuous and allow the UTS to cycle power to the circuits as necessary.

[Anonymous user · Accepted solution]

Thanks for the responses!

The answer to #3 is interesting if i am understading your reponse correctly - so unlike when a generator is the source, the UTS does not attempt to "protect" the UPS by shedding uninteruptible circuits if the total load exceeds the UPS power rating.  Instead, it will let the UPS handle the overload.

Thanks again.

Jason