How to place "Power On" indicator lights?
Your post is a little garbled and a block diagram of your setup (use the built-in schematic editor) would be a big help. I don't think your wiring scheme is correct.



Figure 1. UPS block diagram from AltechCorp.com.


The UPS + and - terminals are both 24 V DC input (while mains power is on) and output when mains power has failed.
The power supply shown in Figure 1 should be 24 V DC nominal.


Indicator lamps can be wired from the 'DC OK', 'BAT FAIL' AND 'BAT DISCHARGE' relay contacts.









simulate this circuit &ndash; Schematic created using CircuitLab

Figure 2. LED indicator schematic.

How it works

Let's assume that the mains power supply is giving out 24 V.


D1 provides a 0.5 V drop. (See BAS70 datasheet page 7).
When mains is on D2 lights with 24 V on the anode and about 24 - 0.7 (D4) - 2 (D2) = 21.3 V on the cathode. Because of the three two diodes in its circuit D3's anode voltage will be lower than D2's and will glow dimly if at all.
When mains fails D2 turns off and D3 will now light.
D4 is required to protect D2 from high-voltage reverse bias.
D5 is required to give the same voltage drop as D4.
D6 ensures that the voltage difference between the two LEDs is high enough to work as intended.


I haven't tested this.