Hello all,
I have just connected the MNSPD 300 to my solar panel distribution box, red wire to PV+ ,Black to PV- and green to ground,the PV voltage is around 60 volts the leds are not on.
It is normal with this voltage that the LEDs are off or there is a problem on the device?
many thanks for your help
Fabio
Do you have the rest of your system on and hooked up to battery ?
I am guessing that needs to be on since my spd stays lit up all night on the combiner box. So it must get power from controller .
Larry
Hello,
the output of the combiner box PV+ and PV- is going to the PV inputs of the classic.
Fabio
Just to add some info my MNSPD is an old version at least 8 year old that I have just installed now for the first time
thanks in advance for your help
Fabio
https://www.midniteftp.com/support/kb/faq.php?id=96
SPD - How do I test the SPD?
Last Updated 6 years ago
We need to verify the SPD is compromised and not something else in the System.
PROCEDURE ONE
TESTING procedure for the SPD300-DC and SPD600 and SPD115
Using a simple (good) 9 volt battery.
Connect the RED WIRE to the battery POS and the BLACK WIRE to the battery NEG.
Both LEDs should light.
PROCEDURE TWO
TESTING the SPD300-AC, SPD300-AC/DC and some older version SPD115.
Connect the RED WIRE to the battery POS and the GREEN WIRE to the battery NEG.
A single BLUE LED should light.
Connect the BLACK WIRE to battery NEG and the GREEN WIRE to battery POS.
The other BLUE LED should light.
Is your system grounded ?
I was putting an SPD on combiner box once and had no LEDs, but then I touched the metal combiner box and the LEDs lit up. It was awhile ago but I guess that I had a grounding problem.
Older AC/DC MNSPD300's require a BATTERY NEG to GROUND BOND usually through a Ground Fault Protection device AKA GFPD. We make these devices and our Classic charge controllers have the GFPD built-in. Hard-Bonding is allowed by code but you need to follow those code rules for hard-bond.
Hello thanks for the replay and suggestion,
I will test the device with the 9 Volt battery as suggested, in my system the groud and negative are not connected together and I have not activated the GFP on the Midnite charge controller, the question is if the test with 9 volt battery are showing that the device i working living the connection as they are now
Red to PV+ Black to PV- and green to ground will still give a protection even too the leds are not ON?
Many thanks for your help
Fabio
Years ago, there were certain SPDs that had to be changed to NOT light the LEDs with voltage between the GND and HOT1 or HOT2. This was because PV inverters would trip their internal GFPs or internal PV leakage tests just from lighting up the LED through GROUND (green wire.) Lighting the LED between HOT1 and HOT2 only fixed this problem.
I do not remember which SPD models are which in this case but that lighting of the LED method was the only difference. The internal SPD MOVs of course will conduct to GND from HOT1 and/or HOT2 of course.
Anyway, that is the rhyme and reason for that difference.
boB
Thanks Bob,
yes my device is a device of the year 2012 could be one of those you mentioned, in this case even too the led are off the device is still protecting if I understand well.
have good day
Fabio