SPD300DC to protect 120vac out only?

Started by SolarMusher, May 07, 2015, 10:32:29 AM

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SolarMusher

Hi Folks,
I currently have two inverters and have an unusual problem:
A Magnum 4448AE 240vac on epanel which is already protected in and out with 2x SPD300DC and an Outback vfx3648 epanel that I added recently to supply its own dedicated loads. Neutral is common on both inverters with a single neutral/ground bond in the system, DC negative is common on both inverters from shunt to shunt with a single neg/ground bond in the magnum 240vac epanel. All was fine until I added a new SPD300DC on the vfx3648 epanel to protect the 120vac output and connected it as usual. Both leds were blue and gave some voltage (3/10V) on the input side of each epanel with the gen off. In fact, it seems that these two spd's mounted on each epanel and protecting the same gen input are the problem. This input voltage makes me nervous, where does it come from? Is that a real problem. Any ideas how to solve this issue?
I tried to connect just one leg of the spd to the vfx 120vac epanel output but it didn't help, leds x2 are dim but still on with no more real voltage on the input gen side (gen off). I guess that to parallel the gen input on both epanels doesn't help and that I should think to give it up.
Thanks for any inputs,
Erik

Off Grid with 4kw PV | 2x Classic 200/WBjr | 2x Outback VFX3648 Epanel | 3x SPD300 + 1x Schneider HEPD80 | Hub + Mate + PSX-240 | Volthium 400Ah/51.2V LFP battery bank + Trimetric | 1500 watts AC water heater | Kubota 11kw GL diesel generator

Halfcrazy

So just to make sure the issue is the 3ish volts showing on the generator side? I suspect thats just the LED drive pulling that leg up a few volts
Changing the way wind turbines operate one smoke filled box at a time

SolarMusher

Ryan, I've connected both leads of the outback epanel spd to the output busbar only as the 240vac gen input is already protected in the 240vac magnum epanel. Now the leds are so dim that it's hard to say if the spd would still make its job.
One thing that I don't understand is where did it pull these few volts with the gen off? Anyway, output led should be off when no voltage on the gen input, that's how it was working with only one inverter?
Don't you think that I should add a second neutral/ground bond in the outback e-panel and use the vfx to invert only (no charging)?
Thanks,
Erik
Off Grid with 4kw PV | 2x Classic 200/WBjr | 2x Outback VFX3648 Epanel | 3x SPD300 + 1x Schneider HEPD80 | Hub + Mate + PSX-240 | Volthium 400Ah/51.2V LFP battery bank + Trimetric | 1500 watts AC water heater | Kubota 11kw GL diesel generator

Halfcrazy

So a 300 SPD DC on the 120 wont really want to lite LEDs like that. So What I would do is take the black on AC in and Red on Neutral and green to Ground

Ryan
Changing the way wind turbines operate one smoke filled box at a time

SolarMusher

Quote from: Halfcrazy on May 07, 2015, 03:30:19 PM
So a 300 SPD DC on the 120 wont really want to lite LEDs like that. So What I would do is take the black on AC in and Red on Neutral and green to Ground

Ryan
It's the AC out that I'd need to protect. Is that ok to wire it black on AC out and Red on Neutral and green to ground?
Erik
Off Grid with 4kw PV | 2x Classic 200/WBjr | 2x Outback VFX3648 Epanel | 3x SPD300 + 1x Schneider HEPD80 | Hub + Mate + PSX-240 | Volthium 400Ah/51.2V LFP battery bank + Trimetric | 1500 watts AC water heater | Kubota 11kw GL diesel generator

SolarMusher

Quote from: SolarMusher on May 07, 2015, 04:19:49 PM
Quote from: Halfcrazy on May 07, 2015, 03:30:19 PM
So a 300 SPD DC on the 120 wont really want to lite LEDs like that. So What I would do is take the black on AC in and Red on Neutral and green to Ground

Ryan
It's the AC out that I'd need to protect. Is that ok to wire it black on AC out and Red on Neutral and green to ground?
Erik
Ryan, I've wire it AC out, neutral and ground and it seems to be ok with both leds on. Great!
Thanks for your help, you make my day. It's too hot here since a few days in Qc and it won't be long to get a storm. These vfx are nice but also very sensitive to high voltage, I had to change the boards two times in the past years and I want to protect it as much as possible.
Thanks a lot,
Erik
Off Grid with 4kw PV | 2x Classic 200/WBjr | 2x Outback VFX3648 Epanel | 3x SPD300 + 1x Schneider HEPD80 | Hub + Mate + PSX-240 | Volthium 400Ah/51.2V LFP battery bank + Trimetric | 1500 watts AC water heater | Kubota 11kw GL diesel generator

SolarMusher

Ryan,
Could you explain what are the differences between 300AC and 300DC SPD's. I guess that if you build it now in both versions, there should be good reasons?
Thanks,
Erik
Off Grid with 4kw PV | 2x Classic 200/WBjr | 2x Outback VFX3648 Epanel | 3x SPD300 + 1x Schneider HEPD80 | Hub + Mate + PSX-240 | Volthium 400Ah/51.2V LFP battery bank + Trimetric | 1500 watts AC water heater | Kubota 11kw GL diesel generator

Halfcrazy

Yes the ONLY reason we made 2 models was because with the old SPD300 only one led would be on when installed on DC.

So with that said we now have 2 models that are physically identical and work on AC or DC just have a difference on there LED signals:

SPD300-AC this model Senses power between Red and Green for one LED and Black and Green for the other LED (Same as the old SPD300)
SPD300-DC this model senses power between Red and Black for one LED and Black and Red for the other LED this way on a DC system you still have 2 LEDs

Now all that said the model numbers are slightly misleading. I would have gone with:

SPD300-120VAC
SPD300-DC-120/240VAC

But thats Really confusing so we went AC and DC. If you only keep one on the shelf the AC is the one to keep as it works for anything but would only have one led on DC like the older ones

Changing the way wind turbines operate one smoke filled box at a time

SolarMusher

Ok, thanks Ryan to take the time to explain.
Anyway, AC or DC it's a great product!
Erik
Off Grid with 4kw PV | 2x Classic 200/WBjr | 2x Outback VFX3648 Epanel | 3x SPD300 + 1x Schneider HEPD80 | Hub + Mate + PSX-240 | Volthium 400Ah/51.2V LFP battery bank + Trimetric | 1500 watts AC water heater | Kubota 11kw GL diesel generator

vtmaps

Quote from: Halfcrazy on May 08, 2015, 03:11:14 PMthis model senses power between Red and Black for one LED and Black and Red for the other LED 

Perhaps I'm over-thinking this, but what's the difference between Red and Black, and Black and Red?  --vtMaps