Hi guys, when i first fitted my solar set up, which is very basic : panel, MPPT control, wired ( with fuse ) direct to battery, My blue box showed a blue light, Bulk. I’ve just noticed, my box now isn’t displaying anything, even with sunshine. I’ve checked voltage at the 3 pairs of terminals at the bottom with my volt meter, as expected Batt is showing 14.25v (probably because I’m on EHU), Load to showing 14.25v, but the PV terminals show varying voltage for a split second ( 16v-20v) then 1.
What should my blue controller be showing even on a dull day ?
PV connections are sound, PV connections on the panel were wired in when it was supplied. IE panel was supplied with a length cable fitted.
Can any-one shed any light on this? No pun intended.
on a dull day, usually the blue bulk light should be on.
When dark, with Vpv being < Vbat then the blue led should be flashing.
Blue bulk goes on steady when Vpv > Vbat+5.
As the load has the same volt as bat, then the internal fuse is good, and the unit load control is working.
Disconnect the PV and measure the PV open circuit voltage, and if possible the short circuit current.
Also do check the voltage on the pv terminals with the PV disconnected.
If you have a VE - direct - usb lead then use that and VE connect to connect to the controller and diagnose the unit.
pv terminals showed 1.5v dropping to zero with meter held on them.
PV wiring flashed various 16-19v, then 1
But when i reconnected PV to terminals, the terminals showed steady 19.78v
Short circuit current is slightly above my pay grade ( I’m a mechanical engineer for my sins )
But still no display lights on controller unit.
Having done some research i know the controller needs the PV to be 5v above battery voltage, but i also thought the blue light should still flash even when there is not 5v more than battery voltage.
Don’t really follow this: Measure voltage on PV input to MPPT Without the PV wires connected, and measure the PV voltage om the module wires without connecting them to the MPPT.
Yes, the BLue LED should flash without the PV connected. If it doesn’t then you need the VE-direct cable to “talk” to the internal controller to see if it is alive.
Otherwise, if the unit is <5 years old, you can return it for warranty, else replace as it is faulty.