E-stop wiring appears to be oddand as Ger pointed out you aren't supposed to send 24vdc to UB1/X103.
1. It looks like the E-stop is an NO switch, not a standard NC switch.
2. If the E-stop is activated, it kills 24vdc to UB1, as well as the CM3 contacts, as well as UB1-X103
3. Not sure what the point of S3 is, unless you want a separate switch to turn off the drive and VFD bus power. Or were you attempting a 'reset' type switch?
If this is correct, then there is no point signaling X103 as you've just turned off the UB1 completely.
I think you might want to consider the following scheme:
1. Momentary NO - "ON"
2. Momentary NC - "OFF"
3. Momentary NO - "RESET"
4. Latching NC w/2 sets contacts - "ESTOP"
5. DPDT Relay - "R1" (additional relay #1)
6. DPDT Relay - "R2" (additional relay #2)
R1 is wired as a holding relay using "ON" and "OFF" - this prevents unintended restarts after a power interruption.
R1 Input contacts: 24VDC from breaker/fuse
R1 Output contacts: to R2 input contacts and anything else you want to feed 24VDC when in an E-stop condition (red light, VFD logic, ect)
R2 is wired as a holding relay with "RESET" (set #1 NC contacts) and "ESTOP" to the relay coil.
R2 Input contacts: 24VDC from R1 output
R2 Output contacts: 24VDC to UB1/NO3
UB1/CM3 to contactor coil.
"ESTOP" (set #2 NC contacts) UB1/X103 and UB1/0V for signaling UB1 safety circuit (UB1/X104 to /X109) and UCCNC.
In this scheme when you press the ON button, the UB1 is powered up, but the drives do not power up and if the e-stop is engaged UB1/UCCNC knows there is an e-stop condition.
To power the drives, you unlatch (close contacts) ESTOP, and then press RESET. This energizes coil of C1 and powers the drive/VFD bus.
The fundamental idea with this scheme is that:
1. User and UCCNC/UB1 can assert an e-stop event, but
2. UCCNC/UB1 cannot reset from an e-stop event without human intervention via mechanical relay and the RESET button.