Fuse between inverter and panel blew, what should that tell me?

[so_cal_burbs]

Had a 8kw system installed early this year. Has a SolarEdge 7600HDWave inverter connected to the electric panel with a disconnect box with a fuse (or maybe a fusible link?) between them. Yesterday afternoon the system stopped producing power and when I inspected it today I found the fuse box plastic insert deformed from the heat of that link failing. Breaker never tripped. I switched off the system at the breaker and contacted my installer.

Why would the fuse melt before the breaker tripped? What should the installer inspect while replacing the failed part to reduce the chance of it happening again?

Thanks.

[jflorey2]

Why would the fuse melt before the breaker tripped?

Fault between fuse and breaker.
Incorrectly rated fuse or breaker.
Faulty fuse.

[Mike90250]

When Fuses melt their holders:
Improper install
Cheap ass holder w/out enough spring tension to make solid contact to fuse, even milliohms of resistance, with enough amps, will generate a lot of heat.

8Kw @ 240Vac = 33A x .1V 3.3w of heat, with no heat sink other than the wires, it has 5 hours to heat up and get melty like a grill cheese sandwich.

[SunEagle]

I agree with Mike. If the fuse holder fails from heat that is usually a poor or loose wire connection.

Time to break out the IR camera. That will find a poor connection real fast.

[so_cal_burbs]

Thank you for the replies, I really have learned a ton from those that post here from initial research through today.

Glad to read the opinions that it is most likely a simple fix. Installer is coming out later this week to replace the whole fuse box. If it fails again I'll update this thread.