Replace Internal String Fuse - Delta M125HV 113 Operation And Installation Manual

5.3 Replace Internal String Fuse

The combiner box utilize standard 60mm x 196mm PV fuses and associated at
both positive and negative side.
Because of the TL design, both strings are floating and not connected to ground.
Standard fuse of M125HV_113 is 250A, the specifications for the required fuse
and fuse brands used in the factory are listed below.
Rated current
Rated voltage
Operating Class
Fuse Type
Check the fuses if the power generation of inverter is abnormal using following
procedure:
1. Check to determine if the input current measurement is zero, which will most
probably indicate a blown fuse.
2. Follow Section 5.1.1 to disconnect M125HV_113 from Voltage Sources.
3. Follow Section 5.1.2 to open the cover of combiner box.
4. Use multimeter to measure if the fuse got blown.
5. Replace the fuse if necessary.
6. Follow Section 5.1.3 to put the cover back to the combiner box and follow the
torque to tighten the cover.
- Ensure DC and AC cables are always de-energized during the maintenance to
avoid the shock hazard risk!
Table 5-2: Combiner Fuse Specification
250 A
1500 V
Solar PV
60 mm x 196 mm
DANGER : ELECTRICAL HAZARD!!
IEC listed
Typical Mfr
Mfr P/N
63
Maintenance
IEC 60269-6
Littelfuse
SPNH250.X2XLDE