Delta STL1 fault code meaning
Delta / STL1
Series: C2000 Plus, CFP2000, CH2000, CP2000, DPD-K
STO missing 1
AC motor drive
Meaning: STO1~SCM1 Internal circuit diagnostics detected an error.
Possible causes
- The jumper between STO1 and SCM1 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, ME300, MS300
STO missing 1
AC motor drive
Meaning:
Possible causes
Source: C2000-R User Manual P218; ME300 Series User Manual (DELTA_IA-MDS_ME300_UM_SC_20250407) P181; MS300 Series User Manual (DELTA_IA-MDS_MS300_UM_TC_20260417_v2) P247
Series: MH300-HS, MH300
S1 Internal circuit diagnostics detected an error.
AC motor drive
Meaning:
Possible causes
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
Series: MS300-HS
Channel 1 (S1~DCM) safety circuit error
AC motor drive
Meaning:
Possible causes
Source: MS300 (High-speed Models) (DELTA_IA-MDS_VFD MS300_high_UM_TC_20170306) P141
Series: MX300, VP3000-E, VP3000
Safe torque loss 1
AC motor drive
Meaning: STO1~SCM1 Internal circuit diagnostics detected an error.
Possible causes
- The jumper between STO1 and SCM1 is not connected.
- Hardware fault
Source: MX300 Series User Manual (DELTA_IA-MDS_MX300_UM_TC_20260226) P139; VP3000-E & VP3000-EHS User Manual (DELTA_IA-MDS_VP3000-E-VP3000-EHS_UM_SC_20260306) P402; VP3000 Series User Manual (DELTA_IA-MDS_VP3000_UM_TC_20250523) P437
Series: VFD-ED
Safe torque loss 1
AC motor drive
Meaning:
Possible causes
Source: VFD-ED Series User Manual (DELTA_IA-MDS_VFD-ED_UM_SC_20170315) P126