Delta STL3 fault code meaning
Delta / STL3
Series: C2000 Plus, CFP2000, CH2000, CP2000, DPD-K
STO missing 3
AC motor drive
Meaning: An error was detected by internal circuit diagnostics for STO1~SCM1 and STO2~SCM2.
Possible causes
- STO1 and SCM1, or STO2 and SCM2
- The short-circuit jumper is not connected.
- Hardware fault
- Poor contact on the IO plug-in card
- Version mismatch between the IO plug-in card and the control board
Source: C2000 Plus Series User Manual (DELTA_IA-MDS_C2000 Plus_UM_TC_20250522) P422; CFP2000 Series User Manual (DELTA_IA-MDS_CFP2000_UM_SC_20250731) P284; CH2000 Series User Manual (DELTA_IA-MDS_CH2000_UM_SC_20251030) P382; CP2000 Series User Manual (DELTA_IA-MDS_CP2000_UM_SC_20250704) P392; DPD-K Series User Manual (DPD-K user manual_20211224) P317
Series: C2000-R
STO missing 3
AC motor drive
Meaning:
Possible causes
Source: C2000-R User Manual P218
Series: MH300-HS, MH300, MS300
An error was detected by internal circuit diagnostics
AC motor drive
Meaning: An error was detected by internal circuit diagnostics
Possible causes
- STO1 and SCM1, or STO2 and SCM2
- The short-circuit jumper is not connected.
- Hardware fault
Source: MH300 Series (High-Speed Models) User Manual (DELTA_IA-MDS_MH300-HS_UM_SC_20241213_v3) P253; MH300 Series User Manual (DELTA_IA-MDS_MH300_UM_TC_20260505) P293; MS300 Series User Manual (DELTA_IA-MDS_MS300_UM_TC_20260417_v2) P247
Series: MS300-HS
Internal circuit error
AC motor drive
Meaning:
Possible causes
Source: MS300 (High-speed Models) (DELTA_IA-MDS_VFD MS300_high_UM_TC_20170306) P141
Series: VFD-ED
Safety torque loss 3
AC motor drive
Meaning:
Possible causes
Source: VFD-ED Series User Manual (DELTA_IA-MDS_VFD-ED_UM_SC_20170315) P126