Bypass not in range; high voltage

[Anonymous user]

I have a Smart-UPS RT 5000 XL my network management card is omitting error:
1 Critical Alarm Present
Power Problem While In Hardware-Failure Bypass

UPS: Bypass not in range; high voltage

this just started earlier this morning...is this safe for my servers to run with this error and why could this be happening since nothing has changed in my power.

what should I check?

thanks,E

[Anonymous user]

the bypass has a configuration for high and low voltage you can check and reconfigure this range through the nmc card.
if the input voltage is high or low than the configured range you will received this message and the bypass will drop load to protect them from electrical damage.
the only thin g you will face is that the load will shut down and it will always be protected.

[BillP]

you probably need to look into this. it seems as though the UPS is in bypass due to a hardware failure. thus, passing utility voltage through to your equipment. then, during that time in bypass, it is seeing high voltage coming in.

to start, get the model and serial number off the back or bottom of your UPS. check the event log for any other critical or warning events. look at the front LED display of the UPS and make note of whatever LEDs are on there and you can let us know. though, this may require a hardware replacement so you may want to call tech support in your region.

[BillP]

You need to look at your data log to see what the high input voltage is and then address the problem with the utility power at your UPS's installation site. The UPS is trying to warn you about voltage that is too high so that the UPS cannot go to bypass if it needed to for various reasons (overload, fault, etc).

[Anonymous user]

HI, I am also receiving the same error message for my UPS. However, UPS shows no alarms or any hardware failure alert.

The Upper Voltage is set to 255 and in the logs i can see that it has not crossed 255.

Mq8KzUNoruhrdsmIWc0dag%3D%3D.png

Can anyone please suggest on this? 

Thanks

[BillP]

Hello,

A likely cause for the UPS to keep logging 'Bypass not in range', according to the above log snippet, is the approximately 20V difference between the configured output voltage, and the max input voltage. Looking at the logs, I believe your UPS is a Double Conversion On-line model? If so, these models allow configuring different output voltages for online operation. Changing the UPS output voltage from 230V to 240V (if this is acceptable to the load equipment) should eliminate, or at least reduce, the 'Bypass not in range' events. Please note the UPS output voltage can only be changed if the UPS output is turned off.

[Anonymous user]

Hi Szabi,

Thanks for your reply. Actually I am not much aware about the model. But after reading your post, seems like we can ignore these events? If so, i assume the UPS hardware is working fine.

[BillP]

Hi Nitin,

'Bypass not in range', logged when there is a 20V difference between output and bypass voltages, does indeed indicate normal operation. If the only event that is logged is 'Bypass not in range', then the only risk of the UPS output being affected is if the UPS must go to bypass. This only happens in the event of an overload (should not be the case, with the under 20% load that is shown in the log snippet), or a significant fault. 

[Anonymous user]

Thanks Szabi for the reply.

I have one more question.  the only risk of the UPS output being affected is if the UPS must go to bypass - Does this mean during this alert "Bypass not in range:high voltage", the UPS must change the output supply from Mains to Battery?

But we can see in the logs, the UPS is not going on battery during this, Could be a fault in UPS?

[BillP]

Hi Nitin,

Apologies for the confusion. The UPS would only switch to battery operation if the input voltage goes outside the acceptable values for mains operation, this is typically 160V - 275V (exact thresholds may differ slightly depending on UPS model).

During the 'Bypass not in range: high voltage' event, if the input voltage is around 250V, it is normal behavior for the UPS to not switch to battery operation, as the input is still acceptable for online operation - it is just not acceptable for bypass operation.

[Anonymous user]

Hi Szabi,

Thanks, This indeed makes sense now.

According to your previous replies, If there is a 20V difference between configured output voltage (230V in my case) and actual output voltage (which is hitting 250V some of the times, from the logs I can see), most likely causing these alerts (bypass not in range:high voltage). I apologize but still i am still trying to understand the cause for these alerts.

And, to suppress these alerts, Either we can increase the configured output voltage (from 230V to 240V depending on the equipments load) or we can increase the maximum voltage configuration (from 255V to 275V).

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[BillP]

Hi Nitin,

Apologies for the delayed response. The reason for this event, in our particular case, is the fact that the UPS deems the bypass voltage (250V) to be too high when compared to the configured output voltage (230V). Assuming the UPS would have to go on bypass in these conditions, the output voltage would immediately increase by 20V, and certain load devices may not handle a 10% increase in input voltage well. I believe that in this case it is the output voltage configuration (from 230V to 240V, if the load allows) that will eliminate the events. Increasing the Bypass Upper Voltage from 255V to 270V (maximum configurable upper threshold) could also reduce the number of 'bypass not in range' events, but may still leave a wide enough voltage difference between Vmax and Vout.

[Anonymous user]

Szabi,

Does a huge difference between Vmax and Vout reduce the power factor?What would be the consequences ? Also, i would like to know if i need to shut down the devices(load) before i make any changes in bypass upper voltage ?

[BillP]

Hi Ankit,

The power factor is a UPS specification and is related to UPS design rather than input voltage. The output power factor specifies the maximum active and apparent load the UPS can tolerate by design. For example, a 10kVA UPS with an output power factor of 1.0 can handle loads up to 10kW active power and 10kVA apparent power. On the other hand a 10kVA UPS with an output power factor of 0.8 can handle loads up to 8kW active power and 10kVA apparent power.

Bypass is deemed out of range if the difference between Vmax and Vout is too high due to the fact that some load equipment is not likely to handle an immediate 10% input voltage increase well, should the UPS need to go on bypass. 

Changing the bypass upper voltage while the UPS is on battery or online will not have any immediate effect on the UPS output, or load, as the bypass upper voltage setting is only taken into account when the UPS needs to transfer to bypass operation.

Changing the bypass upper voltage while the UPS is in bypass will cause an immediate change in the output voltage -if the load does not handle input voltage changes well, then it is best to turn the load off.

[Anonymous user]

Thank you Szabi. 

I have one more question. If my output voltage is 230 V then what should be the input voltage to declare it a high difference between Vmax and Vout ?

[BillP]

Hi Ankit,

Sorry for the late response. From what I've seen, it's usually +/- 20V relative to the output voltage, for Bypass not in range to be declared. With 230V out the, UPS could declare 'Bypass not in range; high voltage' at 250V input.

[Anonymous user]

Thanks Szabi. 

Could you also look for one more issue? Though i set my output voltage to 230 V, my UPS rated output voltage is different from output voltage. I don't think if my devices can bear such a change. Is it because of output lower voltage which is refraining UPS to go under bypass range ? Do i need to recalibrate from 208 to 160 or odd ? Or Do I have any internal failure/fault in my UPS ?

NR2PHmmFq4UAYw4DBb9taw%3D%3D.png

-Ankit Godiyal

[BillP · Accepted solution]

Hi Ankit,

The reason your actual output voltage is different than the rated output voltage is due to Green Mode being enabled. In Green Mode, the UPS operates at a higher efficiency, but as a trade-off, utilizes its AVR (automatic voltage regulator) to keep the output voltage within acceptable range of the input voltage.

If your application requires a constant 230V input, you can disable Green Mode in order for the UPS to start supplying a steady 230V to the load. The UPS outlets will need to be rebooted for the output voltage change to take effect. Hope this helps!