Sounds familiar, so here are some ideas to try.BTW, I viewed the images, and it appears that the Batteries are in the cabinet to the left, and all the control + inverter stuff is in the right side cabinet
[*] Verify that there is 120VDC at the Battery with the output leads,
[*] Verify the polarity is correct at the Inverter Assembly's DC Input,
[*] Verify that the UPS System control is set for "Normal Use", not in any type of test mode or override mode,
[*] Verify that the Transformer(s) connections are setup correctly - input and output wise,
[*] Check that all interlocking relays are functioning when the transfer takes place,
[*] Verify that the main system power Transfer contactor(s) are latching / unlatching as needed, and that any interlock contacts are functioning + wires are terminated properly,
[*] Verify that the input and output AC Power Circuitry is terminated properly, and that there is an output - independent of the input power supply - during normal mode operation,
[*] Verify the H.O.A. switch is in the Auto setting.
Try turning off the Circuit Breaker that feeds the UPS Inverter, and see if this test makes the device work properly.
Also, test the output voltage during the tests you have described, and verify the output is AC, not DC; and that the output voltage is correct.
The inverter should be supplying output power, even when the system is in normal operation (unless this inverting supply is not a "UPS" type).
If all field terminations + Battery terminations & jumpers are correct, along with proper input voltages & configurations, then the problem exists within the control logic and / or other hardware / devices; which would be a Manufacturer's issue.
A call to them should be made, and the word "Warantee" should be mentioned
If this is not a new UPS system, or there is no current warantee, then it's time to get specs and schematics for it and begin looking for which parts "lost their smoke"
Good luck with this.
Let us know how things turn out.
[This message has been edited by Scott35 (edited 09-28-2005).]