Shutdown a UPS using a dry contact, but stay off until battery charged

[matlan_apc]

This was originally posted on APC forums on 5/29/2015

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I'm trying to get my SMX3000HV to be shutdown either by a dry contact or when battery is too low. In both cases i want the UPS to stay off, until the battery is charged to some level.

The shutdown shall be signalized to the connected PCs using snmp and powerchute (if there is another solution, i can write batch-files and receive smnp-traps)

This is my hardware

• SMX3000HV
• AP9631
• AP9810
• AP9630
• AP9613

First level support told me to buy the additional hardware AP9631 and AP9810 but this didnt help at all!

Any good ideas very appreciated, because i'm desperate and we really need to get this working!

I've tried a lot of combinations, but using the dry contact, the UPS either stays off on power return, or is turned on no matter of battery level.

Thanks in advance, i really hope there is one exerienced person out there, that knows a solution!

[matlan_apc]

This was originally posted on APC forums on 5/29/2015

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Hello Angela

Thanks for your reply!

I found those settings in the Webinterface. AFIK if I use the turn off and stay off setting, the UPS stays off. But this is not what i want.

We are using the UPS as a buffer. In case of a powerloss, the system should be operatable as usual, until the battery is empty or someone turns it off using a dry contact.

In an optimal case, turning off the system would also work when power is still there. But i think this is against the nature of the UPS 😃 So we cut the powerline with the same dry contact as well using a relay.

We need the UPS to charge its battery before turning on. When does the "Min return time" apply? What command do i need to use? I've tried many. Upon Shutdown from the dry contacts the UPS is not charging first. Same if I use Telnet and CLI.

Could Powerchute confuse the shutdown?

If you have another good idea, working with relays and UPS outputs, this is doable as well. We just need to get this behaviour.

[BillP]

This reply was originally posted by Angela on APC forums on 5/29/2015

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Hi Mathias,

Ok, I misunderstood on the turn off thing and read it wrong I think. So the turn off and stay off would not apply or work for what you want. I thought you said turn off and stay off OR wait to charge up to a particular charge level.

You can turn off the UPS output power when AC power is present even if the battery is charged but then you'll need to command it back on via some means (dry contact, web interface, etc). Minimum return runtime would not apply here since the battery would be charged up. You may want to do a separate input for on and off and then the only things at the outlet group level that should apply would be your power on/off delay. 

Minimum runtime is usually used for scenarios where you have a power outage, your UPS is discharged, and you want to avoid a situation where the power is trying to come back on but going on/off constantly while stabilizing. When AC power tries to come back, the UPS will try to turn back on (assuming it is set to 0 seconds) and you won't want that if the power goes off again and the UPS has no charge and turns everything off while it was trying to start up again.

In your situation, would shutting off the UPS and specifying a sleep time work for the scenarios where the UPS hasn't run out of battery? That would avoid you having to turn it back on and you could specify a sleep time for it to automatically come back on.

For the situation when the UPS runs out of battery, minimum return runtime setting on each outlet group should be the key to make the UPS wait before it turns right back on when it is discharged. When the UPS turns off, it takes a snapshot of the load percentage so that it knows what it will take to reach whatever you set it to for your particular load % (ex. 20 minutes).

[voidstar_apc · Accepted solution]

This was originally posted on APC forums on 5/29/2015

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In addition to what Angela said, I'll summarize a bit before discussing simple signaling.

- APC prefers to work in terms of runtime rather than % of charge. This is because as the battery ages, 20% charge may be less and less runtime.

- Outlet Turn Off Delay (lets call this X) - Set this to the amount of time loads need to turn off. PCNS will automatically set this for outlets its registered with.

- Minimum Return Runtime - Set this to X + whatever time loads need to start up. This ensures UPS can deliver this much runtime before it turns on the outlets after a power outage.

- Load Shedding or PCNS - either PCNS or the NMC can initiate UPS shutdown. From the NMC, this is done by enabling "Turn off outlet groups when... UPS runtime is less than Y seconds". Set this to at least X.

For the dry contact: If you can't make the AP9810 work, the UPS should have built in support for a mechanism called "Simple Signaling" where there's an input "lo_batt" on the RJ50 port. Shorting it to ground causes the UPS to tell PCNS to shut down. See pinout here:

http://pinoutsguide.com/UPS/apc_usb_cable_pinout.shtml