Forum Discussion

Aspirant

Jun 19, 2020

Solved

RN214 NAS not shutting down with UPS power is low or zero

My UPS seems to have started having problems but it shown up a more serious challenge with my RN214 (on latest firmware) - it's not shutting down when the UPS level drops below the threshold. I've had repeated logged messages over the last few days:

System: UPS UPS (Back-UPS ES 550G) battery is low. System will shut down soon.

But it has never shut down even though the UPS is now showing at 0% battery level in the Performance tab.

The shutdown threshold is set to auto.

Any ideas what is going wrong? I see a few messages over the years reporting a similar problem with other NAS models.

StephenB
Jun 21, 2020
Sandshark wrote:

StephenB wrote:

https://networkupstools.org/docs/user-manual.pdf wrote:
The exact behavior depends on the specific device, and is related to:
• battery.charge and battery.charge.low
• battery.runtime and battery.runtime.low

It doesn't sound like it triggered by a particular UPS command (at least not in all cases).

Those are the things you can normally select to determine when the UPS will send the shut-down command.

Well, as I said the manual isn't very clear on tnis point. But my impression from the code is that the NUT software is first translating the UPS messages into it's own set of generic state parameters, and then monitoring that state. I think it then issues it's own shutdown command based on the state changes - at least for some UPS. But I decided against spending the time to figure out exactly what is was doing. There is quite a bit of vendor-specific code in it.

7 Replies

StephenB
Guru
Jun 19, 2020
Maybe try a test - connect the NAS to main power, but still monitor the UPS. Then put another load on the UPS so the battery will drain. A fan, hair dryer, vacuum cleaner - anything that uses a fair amount of power.

Then unplug the UPS from the power, and let it completely drain (until the load shuts down). Note the time when this happens. See if the NAS also shuts down, and if it does, what time that happened.
- richard-york
  Aspirant
  Jun 19, 2020
  Hi Stephen, yes I'll give that a go, thanks. I've tried to work out from the documentation what the "auto" level means in practice, very roughly, but there's no indication at all.
  
  Richard.
  - Sandshark
    Sensei
    Jun 20, 2020
    richard-york wrote:
    I've tried to work out from the documentation what the "auto" level means in practice, very roughly, but there's no indication at all.
    
    I think that "auto" means the point at which the UPS sends a shut-down command. On some NAS, that can be set using the manufacturer's proprietary software. It's normally retained after power-down, so you can set it using the software and a PC and then move the UPS to the NAS.
- richard-york
  Aspirant
  Jun 20, 2020
  Hi Stephen, tests done and everything seems to be working. The NAS shuts down correctly at the right point. The underlying problem is now diagnosed, the battery in the NAS was failing so I was seeing the messages triggered as it was failing to hold charge, rather than becuase of power interruptions.
  
  Thanks for your prompt help and advice, much appreciated.
  
  - Richard.