BE550G failing during power outage

[Anonymous user]

Hi,

I have two big screen Plasma TVs, and I recently purchased a BE550G UPS to go with each.  However, when the power snapped off last night, one of them shut off immediately.  The other unit functioned as expected, keeping the power to that television set without interruption.

Some details about the problem unit:

1. The unit seemed to be functioning normally before the outage, with only the green power light illuminated.
2. It stopped providing power and the power light went out.  However, the built-in alarm continued to sound.

At this point, I'm not claiming the UPS is defective.  I'm simply trying to figure out what could cause it to power off that way.

A little history as well... I have long known it's best to protect sensitive devices with a UPS, and purchasing units for my TVs was something I was eventually going to get around to.  However, the need became more immediate recently because the circuit both of these TVs are connected to has been tripping somewhat frequently.  I have been in touch with my contractor, and I'm waiting for him to come out with his electrician.  In the meantime, this seemed like a good time to get those UPS units I kept talking about.

However, last night's incident has me wondering if the problem is not with the circuit or breaker, but with one of my devices... most likely the TV.  But, I don't understand what that problem could be.  As an IT professional, I work with UPS units regularly.  The most common problem I've seen with them is ineffectiveness due to battery age.  But, I've never seen a power problem cause the power backup to fail instantaneously that way.  I consulted the documentation that came with the UPS, but there was no troubleshooting info that matched theses symptoms.

One last note... as a final test, I shut the circuit down manually.  Both UPS units functioned as expected.  So, that only lends credence to the idea that the problem is coming from the demand side of the equation.

Any thoughts anyone has would be greatly appreciated.

[BillP]

hi Sir,

did you connect both plasma TVs to UPS battery backup + surge protection outlet or surge protection outlet only? you said that built-in alarm continued to sound, is it continues tone or beep 4 times and looping every 30 seconds?

Thanks

Sam

[Anonymous user]

Sam,

First of all, thanks for responding.

Each TV is plugged into the backup+surge protection side of its respective UPS.  I didn't note the frequency of the beeping, but it was not a continuous tone.

Thanks,

Rich

[BillP]

Rich,

If the TV was plugged into a Battery/Surge outlet and the UPS remained on after the outage the most likely cause is the TV does not accept a stepped-approximated sine wave. Back-UPS products output a step approximation of a sine wave when the unit is On Battery. While this kind of waveform is ideal for computers and computer-related equipment, it may not be compatible with the TV.

We have Kbase FA158811 the discusses all of the possible reasons for the system to drop. 

[Anonymous user · Accepted solution]

Bill,

Sorry to be so late responding.  The email alerting me to your response somehow slipped past me.

I checked the Kbase article you referenced, but nothing seems to match up with what I'm seeing.  The stepped-approximated sine wave problem specifically says: "Investigation: This would be the case if only one of the pieces of equipment plugged into the battery backup outlets dropped while the other equipment in the battery backup outlets stay on when the unit transferred o battery power."

In my case, all equipment plugged into the UPS drops.  This seems to happen because the UPS itself turns off.

On top of that, I had a different set of symptoms occur the other night.  Something caused the UPS to trigger, and the red and green lights started alternating while the audible alert sounded.  Power to all equipment on the backup side of the UPS stayed on.

According to the information provided with the unit, the alternating green and red lights indicate the unit is in sleep mode, which is a condition it should be able to reach when the PowerChute shutdown software puts it in that state.  In my case, the unit is not connected to a computer and it is not being managed by PowerChute.

Unfortunately, the only way I could come up with to get the unit back to normal operation was to shut it off and turn it back on.  This defeats the purpose of having the UPS to begin with.

I guess it's starting to look like some piece of equipment I have connected to the UPS is messing with it.  I had assumed that was the case from the beginning, but I was hoping some of the symptoms would provide a clue as to what could be wrong.

Thanks,

Rich