SPD light stays on at night

arby · October 2016

Hello folks,
I just added more panels to my system and added a Midnite Solar SPD to the combiner box. The instructions say that the LED lights go out at night but mine stay on. Just did a test by shutting off the breakers at the charge controller and the lights went out. Soon as I turned the breakers on the lights came back on. Obviously the battery voltage is getting down to the combiner box 150 feet away.
Any idea what I have wired wrong or do i need to add some kind of diode?
TIA
. arby

BB. · October 2016

Measure the voltage across the array at night. It is probably he solar charge controller is feeding a little voltage vac to the array.

Leds will only take a few volts and very little current to light. And all is ok.

If you have near full battery bank voltage, then there may be a problem with the charge controller.

-Bill

arby · October 2016

Thanks Bill.
Since I have to leave today and won't be here at night for some time I just went down to the combiner box and shut off the array breakers and checked the voltage from the top bar + to the negative bar and got full battery voltage DC. Nothing AC. The voltmeter was dropping fairly quickly. After 5 minutes it was down to 14 volts from 55 volts.
-arby

BB. · October 2016

The LEDs do not take any energy... And the solar array may not take that much (if you can measure the current, that would tell you for sure)--Assuming your system is otherwise working correctly--You probably would be better off leaving the array connected and the MX60 charging the battery bank through the winter. The one drawback would be a snow covered array for weeks/months at a time--I don't have an answer for that (I do not know the leakage current of your solar array).

I would suggest calling Outback and finding out if this is "normal" or not.

-Bill

Dave Angelini · October 2016

If you leave the array off and the SPD is not wired correctly to the array side of the breaker it will not be protecting the equipment.
This also could be an issue with the MX-60 (-) array and (-) battery issue they have or a bad MX-60.

arby · October 2016

I wired the SPD to the bar at the top of the breakers. I didn't see how I could wire it to the array side because there are 4 breakers. Should I just pick one?
Thanks
arby

Dave Angelini · October 2016

I worded my reply for others but in your case the combiner is at the array, right?
If so then the output side of all the breakers is best and even if you shut the breakers off the a surge would pobably jump the breakers anyway.
Best to leave them on and disconnect down at the house, and preferably outside the house like the fire guys want.
The concept is you want the SPD to protect the equipment and keep the surge out of the house or equipment area. The same with your low voltage DC SPD. If you shut down the DC disco the SPD should be on the equipment side of the disco/breaker so that it is protecting the Battery side of the CC or other DC loads.

arby · October 2016

I'm lost. Not sure what an SPD does but it looks to me like it short circuits breakers and pops them. But it makes sense that a tremendous voltage spike would easily jump a breaker anyway.
Yes the combiner box I put on is at my panels which are 150 feet from my shed where the CC and the inverter are located. From there it is probably another 50 feet to my fuse panel in the cottage. I have that big 150 amp breaker in the shed by the CC and the inverter..
The inverter is wired into another box above it that feeds the fuse panel in the cottage and I added a breaker for the shed/ workshop as well.
Everything was working fairly well except I never had more than 25 amps at peak time for a 400 amp hour bank. Everything I have read has said that I need 40 amps so I doubled the size of my panels. This required a new combiner box and on and on ,,,,so,,, SPD was highly recommended by everything I read.
I wired in the SPD at the combiner box on the pole but the light stayed on at night which the instructions said would go out.
That is where I am at.
PS: before I left today I switched the wire to the panel side of one of the breakers. I will switch it back next time I'm up but it sounds like it will make little to no difference.
Very confused but learning,,
-arby

Dave Angelini · October 2016

The SPD takes any voltage over it clamping value and shorts it to ground. Hopefully!
It is a weird problem you have and I think it is your MX-60 that has negative array and negative battery connected internally.
Most controllers do not do this anymore.

mike95490 · October 2016

My midnight classic controller "leaks" battery power to the array at night and lights the SPD.
Morningstar does not have leakage and does not illuminate the LED.

Bad Classic. Bad Boy, no dinner tonight.

arby · October 2016

Dave Angelini said:

The SPD takes any voltage over it clamping value and shorts it to ground. Hopefully!
It is a weird problem you have and I think it is your MX-60 that has negative array and negative battery connected internally.
Most controllers do not do this anymore.

I think you are correct. While I tested the voltage at the combiner I also tested the positive terminal to ground and got the same voltage. That left me wondering where I had connected ground and negative but since this process has gone over the last 6 or 7 years assumed I just didn't remember.

-arby

arby · October 2016

mike95490 said:

My midnight classic controller "leaks" battery power to the array at night and lights the SPD.
Morningstar does not have leakage and does not illuminate the LED.
Bad Classic. Bad Boy, no dinner tonight.

LOL,,the blue light special is made by the same folks who make the Classic. Did they test it on a Morningstar?)))

Mountain Don · October 2016

My MN-SPD's blue LED's also illuminate at night. I have confirmed it is feedback from the CC, a MN Kid by disconnecting the breaker between The Kid and the battery bank.

Hill_Country · October 2016

I have two midnite solar SPDs (one on the DC side and one on the AC side). Both SPDs have their blue LEDs on 24/7 and I've got a Midnite Solar Classic 200 CC. Please note that both of my SPDs are mounted on our mini-magnum unit, which also has the CC attached, as well as the magnum inverter, so my SPDs are not out on our combiner box. There is some interesting behavior, however, as to how many of the blue LEDs on each SPD are actually lit based on when the SPD was made (see the midnite forum at: http://kb1uas.com/mnsforum/index.php?topic=2093.msg19593;topicseen#msg19593 ) and whether it's AC or DC.

And in terms of resting voltage at night for the Midnite Solar Classic CCs, please see http://kb1uas.com/mnsforum/index.php?topic=930.msg6269#msg6269 I typically see about 32 volts at night with my 48v system.

I know this is not your exact situation, but hopefully it will help folks understand some of the quirks associated with the equipment.

arby · October 2016

I just changed my MX60 to a Classic 200 and the blue lights are still on.

BB. · October 2016

What is the array voltage? If you have a current clamp meter, what is the leakage current?

-Bill

Dave Angelini · October 2016

Looks to me, and this is not a problem as many have said, that you have the same issue with common negatives. Maybe some help here from people who use this controller. Check the pix?

arby · October 2016

Hmmm, yes I have a negative DC out connected on mine. I guess I don't understand enough about electricity and wiring but since others seem to have the same thing going on with no problems I suppose I will just leave things as they are.
arby

arby · October 2016

Here's what I didn't read in the "Just the Facts" instructions--
<< On the blue terminal block from left to right are

connections for the battery (or battery bank)

positive, common negative for both the battery bank and input, and

DC input positive. You only need to bring a single negative conductor to the Classic if you have connected the

negative from the input source and negative for the battery (or battery bank)

on a separate buss block or a device

such as the Midnite Solar E

-

Panel.

Next time I am up at the cottage I will have a look at how the negatives are hooked up in the breaker Box.
Thanks, arby

mike95490 · October 2016

A classic WILL light the SPD on the PV array at night. Every classic does, even mine.

SPD light stays on at night

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