Unintentionally shutdown of both outlet groups

[BillP]

Hi forum,

yesterday some of our technicians completely destroyed a customers database because of a hard shutdown of his server, caused by APC UPC (Model 1500). What they did was to remote switch off one of the so called outlet groups of the UPS (Model 1500) through the APC GUI. It was the group where the Switch is connected to, which was not accessible anymore. To the other outlet group there is connected a database system. What happened was that without warning and for no apparent reason the second outlet group switched off either. Up to now the database system did not survive the crash, all the attempts to repair the damage have failed. Our client calculates the damage with > 100K $. 

You'll guess, what questions we have: How can such a severe malfunction happen? Could this even be intentional behaviour? Although both outlet groups have own and distinctive on and off switches in the GUI?

Thanks a lot for a clarification!

Stefano

[BillP]

Stefano,

If the Smart-UPS is a SMT1500 then unit has 2 outlet groups. A switched outlet group and a main outlet group. As with a circuit breaker panel when the main is switched off all circuits are powered off. If the main was commended to power down it will tell the switched to power down. The switched will wait any power off delay that has been configured and then power down. The main will wait for the switched to power off and then wait any power off delay it has been configured with and power down. Example switched group has 5 minute power off delay and main has 3 minute power off delay. The main is commanded down. The switched will wait for 5 minutes and power off. 3 minutes after the switched has power off the main will power off. I have to assume the technician commanded the main down which then powered down everything. 

Using the GUI if an outlet group has been commanded down a user can cancel the command by going to control - outlet groups 

Hope this helps.

[BillP]

Hi Bill,

thanks a lot for input. That explains the behaviour. Then it's our fault.

I wonder how it can be that the manufacturer doesn't point that out. Or is this association between the two rows of power sockets so obvious? 

Thanks again and regards,
Stefano.

[BillP]

Hi,

The NMC help file list the outlet group actions as

Controlled Outlet Groups

For UPSs that support a main outlet group, the main outlet group controls the distribution of power to all switched outlet groups:

• If the main outlet group is off, the switched outlet groups cannot be turned on.
• If you turn off the main outlet group, the UPS turns off the switched outlet groups first, then turns off the main outlet group.
• To turn on a switched outlet group, the UPS must turn on the main outlet group first, and then turn on the switched outlet group.

The UPS user's guide list 

Note: The Main Outlet Group functions as a master switch. It will turn on first when power is applied, and shut off last when there is a power outage and battery run-time has been exhausted. The Main Outlet Group must be turned on for the Controlled Outlet Group to turn on.

[voidstar_apc · Accepted solution]

The relationship is displayed on the NMC's web UI, although it seems to have gotten less prominent in recent firmwares. I don't know if that would've helped here.

SUMX517:

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SUMX654:

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[BillP]

Hi Voidstar,

indeed, the graphics in the older version gives a hint, that there is a dependency. But you really would have to be quite concentrated to realize that. The text in the newer Firmware I simply did not understand. "The Outlet Group will turn off immediately... will wait for the switched outlets to turn off..." doesn't make sense to me. May be because I'm no native speaker.

Thanks,
Stefano