Smart-UPS 3000 RM (1st generation) doesn't know its max load!

[Anonymous user]

I have a 1st generation Smart-UPS 3000 that is running its fan continuously. I understand that, unless on-line or charging, this means it thinks it is hot, or at or above 75% of full load, which for the 3000, would be 2,250 watts.

The case and batteries are cool to the touch. (It used to get noticeably warm, without the fan coming on.)

The UPS is currently plugged into a "Watts Up?" power meter, which shows the UPS and its total load is between 550 and 650 watts.

The UPS five-LED load meter is pegged — all five LEDs are on, which means it thinks it is running at least 85% of full load, or at least 2,550 watts! It didn't used to do this!

All five LEDs on the battery charge bar graph are flashing. It was doing this for months before the fan started going non-stop. The manual says nothing about this condition.

I am using four each Group 27 marine deep-discharge batteries in series, and they were being charged at 0.7 to 0.9 amps (trickle charge), and all but one was at 13.8 VDC. One was at 15 VDC, so I replaced that one (hot replacement), but no symptoms changed. It is now "equalized" and all batteries read 13.8 VDC.

I have performed the "braindead" procedure detailed elsewhere in this forum; it does not change the symptoms. Should I repeat it?

It seems to me that the UPS has somehow "forgotten" its capacity, perhaps thinking it's the 900 watt model.

How can I convince this UPS that it is operating well below capacity, so the fan will shut up? A "factory reset" will do!

It has a AP9606 Web/SNMP card, but I have not been able to communicate with it, using the "arp" command, as mentioned elsewhere on this forum. I do not have the proper cable to connect to the non-standard serial port.

Thanks in advance for any help offered!

[Brad_C]

You really need to make up or obtain a serial cable. Plenty of pinouts floating around on the web and you only need 3 wires (TX, RX & Gnd). You could even get a standard 9 pin serial cable and chop it in two, twisting the relevant wires together if you don't have a soldering iron handy.

The load measuring circuitry in the SmartUPS is actually scaled mostly in hardware, so the voltage presented to the ADC at max load is roughly the same across every model in the range. So it can't really actually get that wrong. Having said that, if it has lost its marbles it may have lost the calibration constants that are used to adjust those values and *that* can have a significnant affect on what the UPS thinks it is doing. But, you need a serial cable to really see what is going on.I have a couple of AP9606 here (just had to replace the RTC batteries in both of them as they were losing their time/event log every time there was a power fart). If you get a serial cable, you can use that to set the network parameters on the card too.

[Anonymous user]

Wow, thanks so much for your speedy response, Brad!

Yea, I've been putting off the serial cable thing. I'm an old "solder jockey," and probably have the parts around that I need. I've downloaded the diagram.

Now I have to borrow a Windows/Linux box and a USB —> Serial adaptor. We're a Mac shop here.

Can you confirm the drawing below as what I need?

Thanks again for your rapid response! I'll check back in when I something showing in Terminal.app.

[Brad_C · Accepted solution]

That diagram matches the hacked up job on my desk, so that'd do it. I can't see why you'd need a Windows or Linux box though. Surely there's a decent terminal for the Mac.

I'm running Linux here (on a Mac oddly enough), but anything with a serial terminal will do. Is it really a 1st Generation SmartUPS? That must be ancient?

(edit) So to find out what you have there, unplug the AP9606 plug the serial cable in, get a terminal at 2400/8/n/1 and type 'Y'. The UPS should respond with "SM".

The UPS accepts single character commands and you should get an instant response to a command if it works.

Try Ctrl-A, 'b' and 'V'.

As an example on the much newer 3.5G SU1400RMI2U I have on the desk in front of me :

YSM
^ASmart-UPS 1400 RM
b162.4.I
VKWI

My old SU2200I says :

YSM
^ASMART-UPS 2200
b80.11.I
VMWI

Let's see what yours responds with.

If you want to get in a bit deeper, this is from the apcupsd source and documents the protocol pretty well : smartprotocol.rst

Unfortunately I have very little info on the 1G & 2G units other than what is documented around the traps. The 3, 3.5 & 4G units I've spent a lot of time inside and have a much better understanding of how they work and how to diagnose them.

To configure up the AP9606, just put it in and press enter on the terminal prompt, and you should get a username/password prompt.

Check the serial numbers of the UPS and the AP9606. The first 2 numbers are the year of manufacture. If they are 99 or later you are safe to do a hot plug/unplug on that card. If not, then you really want to pull the mains, pull a battery connector and hit the power button to make sure it's really dead before removal/insertion. You'll need to plug the battery back in to get it to power back up after you connect the mains.

You can do the tests I put above with the AP9606 in the UPS, but if you hit the wrong command it comes out of passthrough mode and you have to log in and out again to get back to the raw UPS protocol. Additionally should it be required, the AP9606 blocks you from getting the UPS into program mode.

(edit2) All SmartUPS are rated in VA and the older units were rated for a pretty poor power factor, so in fact your 3000VA UPS is probably maxed out around 2250W, so 75% of that is about 1680W at unity power factor. Still a long way north of what you are actually loading it with.