SMX2000 high battery temp fault

[MarkC_apc]

I recently purchased a new battery pack for this unit.  It started fine - I left it for an hour or so.  When checked back, it was alarming and had thrown a "high battery temperature" fault.  I shut it down, removed the new pack and removed the cover - the battery temperatures where all fine - none hot at all.  I put the old battery pack in and the fault is still set.  How can I clear this fault and what would cause it without an actual high battery temperature existing??

BTW, the new pack had an initial voltage of 123 VDC.  After removing, it had increased to 127+ VDC, so it was being charged (and was obviously low to begin with!).

More checking - All four "probes" (two per battery pack) appear to have 10-11K ohms resistance, so the temp probes are OK??

[MarkC_apc]

After reviewing the data log - the UPS temperature stays at ~75 oF, but infrequently drops to 32 oF and/or raises to 138 oF for no reason.  The fault did clear, but comes back on (likely when the false temperature is registered).  What gives?

[BillP]

You may have smacked the thermistor that takes the temps in the battery bay when you fitted the new one. Probably needs replacing now.

[MarkC_apc]

I tested the thermistor (TH900) on both the original battery pack and the "new" pack by removing the small metal plate at the back of the pack and then directing hot air directly on the thermistor.  Both respond in the same manner - the resistance drops dramatically between the two "connectors" on the Anderson connector - the ones closest to the "+" side.  The other set of connectors (these are on the "-" side), stay fairly constant around 10K ohms regardless of where the hot air is directed - seems they are not used?  I have also checked continuity from the SMX side of the Anderson to the red terminal plugs on the control board (inside the SMX) - all is OK.  I fear something is wrong in the SMX itself??  

The error messages on the NMC status are "critical" and relate to the high battery temperature fault.  If the unit is down for several hours, the error starts as a critical alarm, but eventually throws the fault code and disconnects the outlet power (and the battery charger circuit).

What is next?  A firmware upgrade in the SMX?  

[BillP]

Mark, 

Can you paste here the firmware of your UPS?

[MarkC_apc]

I've attached the NMC information about both UPS and NMC itself.  Note that I have checked the resistance on the thermisor (TH900) all the way to the red connectors at the control card (disconnected of course) and the readings on both "legs" are around 10k ohms (about 75 oF currently).  See above posts for previous testing.  My conclusion is that there is not anything wrong with the battery cages nor the connections all the way to the actual control board.  

[BillP]

I would advise first to upgrade the firmware on the unit. The procedure is outlined below on FA170679

[MarkC_apc]

I've already upgraded the NMC to 633f.  I'll upgrade the UPS firmware tomorrow.  The unit seems to run OK now, but continually beeps when the outlets are powered - and it does show a critical alarm of high battery temperature.  It seems to eventually throw the "fault" and shutdown the outlets - although it ran for over an hour today without "faulting".  I noticed that the battery temps did not vary from 54 oC on the NMC even though I had tested the thermistor and it was working.  Strange.

[MarkC_apc]

Jonathan;

I have two upgrade files available and not sure which is the one to use;

As stated, my NMC aos file is 633f

thanks,

Mark

[BillP]

The latest FW version for the NMC 2 is 6.4.6. With regards to what firmware you are going to use, can you help me get the ID version of your UPS? This would let us know which firmware we are going to upload on the UPS. On the NMC GUI, please choose About > UPS. Look for firmware revision.

[MarkC_apc]

Attached is the revised NMC output about files (using 6.3.3 - is that OK - or should I upgrade again?)

[MarkC_apc · Accepted solution]

Appears going from bad to worse!

Sequence of major events:

Two days ago - unit working fine in every respect

Replaced the battery pack with a new one recently purchased - unit threw a high battery temperature fault

Test both battery packs and all connections - thermistors in both battery packs working fine and all probe connections complete up to the internal control card

Yesterday upgraded the NMC to 6.3.3

Connected unit to batteries and 120 VAC this morning - battery high temp critical alarm still registering - appears no real reading of temperature as UPS temp stays constant at 59 o C

Turned on all outlets power using NMC - now have three critical alarms - high battery temperature, PFC fault and inverter fault.  Now I'm worried that I cannot upgrade the firmware as it appears the unit has cratered!  I've tried this before on a SMX3000 and the unit completely died.  As you can tell, it is out of warranty.

Any suggestions - or to the junk pile!