rate of change issues causes battery discharge on smt1500

[BillP]

I have been having weird issues for the last few weeks.

The outlet my UPS was plugged into (also has a brother laser printer plugged into it) has been having issues where the UPS would making clicking and buzzing like it was handling small power change and the printer would reboot (the printer was not connected to the UPS).

This has been happening since i got the printer a few weeks ago.

Last night the UPS turned itself off because th batter was drained.  The 4 lights were going in sequence.  I have an NMC.

I let the battery charge, and connected the printer to the UPS.  All was well.

This morning all equipment was off again, battery was drained, UPS was flashing in sequence the 4 lights.  The UPS was going through restart loops every 60 seconds, batter did not appear to have charged.  I cancelled the restart, batter is now charging.

I have a Brultech GEM electricity monitor it indicated voltage varies between 119.6 and 122.6, it only polls once a minute, variance seems low.

I am going to take the printer offline the in case that is affect this.  

1. why does the battery not recharge itself before the UPS attempts to turn on?
2. what could be causing this?
3. why did it log nothing to my syslog server (test works)

help!?

--edit-- event.txt attached - why is the darn log so small?

[BillP]

Hi,

Sounds like the laser printer is drawing enough energy to cause the UPS to see a drop in voltage and causing the UPS to switch to battery. When a print is sent to a laser printer the printer must warm up. During this warm up process inherently the printer draws a grater than average amount of energy called inrush. Your description indicates the inrush is great enough to case the UPS to switch to battery.

I am assuming the printer and UPS are plugged into a standard 15 amp circuit? You should check the printer specifications to see if it requires something greater. You should also check to see what the inrush (initial draw) of the printer is. Even if rated for 15 amps if it is drawing close to max 80 percent of the 15 amps (12 amps) it could be over loading the circuit and causing the systems to power down.  

[BillP]

Thanks Bill, the issue occurs s when it is sitting at 'ready' it draws 70W according to the spec.

Yes this is on normal household circuit, luckily i have an energy monitoring solution, that monitors and aggregates the light and power circuits. I have attached the last 4 weeks of watts over time, some things to note:

• the regular looking daily bump is lights being turned on by home automation
• the printer has been on network since 10/12 or there about - with no change to what it is doing (sits idle most of the time)
• the spikes in week 3 and week 4 getting increasing in frequency with no uptick in printing or new equipment
• I was out in EMEA for last week of oct / first two weeks of November
• the spikes to 900 watts IMO occurred at same time as the UPS (without printer in it) would make noises and at the same time the printer we would reboot and re-initialize
• as such i think the spike might be the printer initializing after each weird event (its why i put the printer on the UPS i assumed that the outlet was having issue) i assumed the printer initializing was symptom not cause....

Amps never exceeded about 5 to 6 amps over that time.

edit--- i guess what i am saying is the printer and ups was in steady state and then issue started with no obvious change i can put my finger on.... i am going to leave the printer unplugged for 48 hours and see if the issue disappears, then i will try bringing it back on a different circuit in the house, then a different socket on the study power circuit.

For reference:

http://support.brother.com/g/b/spec.aspx?c=eu_ot〈=en∏=mfcl8900cdw_all

[BillP · Accepted solution]

To close the thread.  I moved the printer to a different wall socket on the same circuit and the issue has gone away (no impact to the UPS) the printer is still randomly rebooting, so i will go talk to them next.

Thanks for folks help!