Delta oH1 fault code meaning

Delta / oH1

Series: AFE2000

IGBT module overheat

active front end

Meaning:

Possible causes

Source: AFE2000 (DELTA_IA-PQ_AFE2000_UM_SC_20110729) P60

Series: C2000-R, VFD-ED

IGBT overtemperature

AC motor drive

Meaning:

Possible causes

Source: C2000-R User Manual P217; VFD-ED Series User Manual (DELTA_IA-MDS_VFD-ED_UM_SC_20170315) P179

Series: CT2000, MS300-HS, VFD-E, VFD-EL-W, VFD-VE

IGBT overheat

AC motor drive

Meaning:

Possible causes

Source: CT2000 Series User Manual (DELTA_IA-MDS_CT2000_UM_SC_20250522) P247; MS300 (High-speed Models) (DELTA_IA-MDS_VFD MS300_high_UM_TC_20170306) P141; Delta VFD-E Manual P52; VFD-EL-W Series User Manual P57; Delta VFD-VE Manual P65

Series: HES-C

IGBT overheat

hydraulic servo drive

Meaning:

Possible causes

Source: HES-C Technical Manual (DELTA_IA-MDS_VFD-HES_UM_TC_20250715) P100

Series: MS300

IGBT overheat warning

AC motor drive

Meaning: The AC motor drive detects that the IGBT temperature is too high and exceeds the oH1 warning protection threshold (when parameter 06-15 is higher than the IGBT overheat threshold, no oH1 warning is issued; the drive trips directly with a oH1 error).

Possible causes

Check whether the ambient temperature at the site or inside the control cabinet is too
High; are the cabinet ventilation openings blocked by foreign objects?
1.
2.
Inspect the ventilation openings in the control cabinet regularly
3.
If a heat source such as a braking resistor is nearby, change its installation position
4.
Check the heatsink for foreign matter and check whether the fan rotates. Remove foreign matter or replace the cooling fan.
Insufficient ventilation space for the AC motor drive
Check whether the load matches the AC motor drive
1.

Source: MS300 Series User Manual (DELTA_IA-MDS_MS300_UM_TC_20260417_v2) P246

Series: REG2000

Power module overheat

regenerative unit

Meaning:

Possible causes

Source: REG2000 Series User Manual (DELTA_IA-MDS_REG2000_UM_SC_20251117) P92

Series: VFD-DD, VFD-VL

IGBT heatsink overheat

AC motor drive

Meaning:

Possible causes

Source: VFD-DD (Ver. F, S, T & V ) (DELTA_IA-MDS_VFD-DD_UM_TC_20170609) P36; Delta VFD-VL Manual P61