Originally posted by Yoda
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Disconnect switch between solar panels and solar charge controller
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2017 Ford F-350 DRW, '19 315RLTSPlus
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Originally posted by Yoda View PostAM solar responded
Keith,
There’s actually no code regarding mobile solar systems.
"...shall simultaneously disconnect the PV system conductors that are not solidly grounded."
Even I know grounding in RV systems isn't always the best so I would think trying to address this by disconnecting the negative makes sense. Then again, I'm not an electrical engineer like Garret at AMSolar. I suspect there are more Blue Sea switches used for disconnects than dual pole higher voltage breakers so in practical use, it must not matter very much. I still feel good about my choice though. Overkill has always served me well.
Brian & Kellie
2020 Grand Design Solitude 310GK-R, FBP, MORryde IS, 1,460w solar and 540ah BBGC3
2020 Ford F-350 Platinum SRW PSD Tremor, 60g TF fuel tank, Hensley BD3-F air bag hitch
Previous setups:
2019 Grand Design Solitude 373FB-R, 2019 Ford F-350 Platinum DRW Powerstroke, Hensley BD5 air bag hitch
2016 Grand Design Reflection 318RST, 2016 GMC 3500 Denali SRW Duramax, Hensley BD3 air bag hitch
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In the event you choose to break both lines coming from the PV system. https://www.amazon.com/Jonsson-Isola...6637627&sr=8-5 Double pole disconnect switch rated for 50 amps at 750 volts, 30 amps at 1000 volts.
https://jonsson-tech.com product website.Joseph
Tow Vehicle: 2024 GMC K3500 Denali Ultimate Diesel
Coach: 303RLS Delivered March 5, 2021
South of Houston Texas
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Originally posted by Jlawles2 View PostIn the event you choose to break both lines coming from the PV system. https://www.amazon.com/Jonsson-Isola...6637627&sr=8-5 Double pole disconnect switch rated for 50 amps at 750 volts, 30 amps at 1000 volts.
https://jonsson-tech.com product website.
It is amazing that even when we folks here disagree, Safety comes first. This is a great discussion. I will admit I am at a bit of a quandary. With my space limitations, simple switch installation, or the more compact/complex breaker box. I think I need to mock this up on the fit. Both solutions work - What could go wrong???????????
Great discussion folks....you know I just had a chuckle - how would this thread have pan out at the other place???.......probably not good
Back to my corner now for a nap
Keith2018 Reflection 150 Series 220RK 5th whee, Star White 2022 F350 King Ranch CC Long bed (HAL) (CCC 4062lbs), B&W 25K OEM Companion,. SteadyFast system, Trailer reverse lights, rear receiver spare tire holder, storage tube, sumo springs, Victron MultiPlus 12/120/3000, Solar, Custom 6K axles upgrade, and other modifications.
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Yoda Ouch on price is right, but it's safety. Dad was a utility worker dealing with high voltage. I do a lot of "live" electrical work around the house, but DC voltage is nothing to play with. Breakers between the disconnect and the PV would be a good thing in case something happens at the switch.Joseph
Tow Vehicle: 2024 GMC K3500 Denali Ultimate Diesel
Coach: 303RLS Delivered March 5, 2021
South of Houston Texas
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Yoda
I have given this topic much thought over the last several days (been out camping again). As I often caution, I don't know everything--so the 48V limit on the Blue Sea caught me by surprise. I'd focused on amperage and glossed over the voltage limitation.
I checked the open voltage rating on the Renogy RNG-100MB panel I'm using and it's 21.2V. Since I run two in series, the maximum the Blue Sea switch I use will "see" is 42.4, so I'm luckily within spec.
If I was running a higher voltage (or amperage) system, I'd use a Solid State Relay like I've done in other applications on my trailer. Not the cheapest route, but no mechanical contacts to worry about once installed.
For example, if I had four of my Renogy's in series the maximum it would "see" is 21.2v x 4, or 84.8v. Three of these quad-series setups in parallel could generate a maximum of 6.1A * 3 = 18.3A (for my 1200W system).
So what relay would I use for a 1200W system consisting of 12ea 100W panels that has 3 sets of 4 series panels wired in parallel? We already know the maximum voltage is 84.8V and amperage is 18.3A.
Using Crydom's chart at http://www.crydom.com/en/products/pa...erplus-series/ I'd probably choose the DC100D40 or DC100DC40C (not sure what the difference is at this point since this is all theoretical). The rating for output of the relay is 100VDC and 40A. To trigger the relay I'd use a simple on/off switch tied to battery power (12vDC).
So what I *thought* was a simple topic turned out into a learning event for yours truly.
Hope this helps (as someone I know likes to say).
HowardLast edited by howson; 03-27-2021, 01:39 PM.Forum moderators are not GD employees--we are volunteers and owners presumably just like yourself. Unless specifically mentioned otherwise, we have nothing to gain should you choose to purchase a product or engage a service we discuss on this forum.
2017 Ford F-350 DRW, '19 315RLTSPlus
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Originally posted by howson View PostYoda
I have given this topic much thought over the last several days (been out camping again). As I often caution, I don't know everything--so the 48V limit on the Blue Sea caught me by surprise. I'd focused on amperage and glossed over the voltage limitation.
I checked the open voltage rating on the Renogy RNG-100MB panel I'm using and it's 21.2V. Since I run two in series, the maximum the Blue Sea switch I use will "see" is 42.4, so I'm luckily within spec.
If I was running a higher amperage system, I'd use a Solid State Relay like I've done in other applications on my trailer. Not the cheapest route, but no mechanical contacts to worry about once installed.
For example, if I had four of my Renogy's in series the maximum it would "see" is 21.2v x 4, or 84.8v. Three of these quad-series setups in parallel could generate a maximum of 6.1A * 3 = 18.3A (for my 1200W system).
So what relay would I use for a 1200W system consisting of 12ea 100W panels that has 3 sets of 4 series panels wired in parallel? We already know the maximum voltage is 84.8V and amperage is 18.3A.
Using Crydom's chart at http://www.crydom.com/en/products/pa...erplus-series/ I'd probably choose the DC100D40 or DC100DC40C (not sure what the difference is at this point since this is all theoretical). The rating for output of the relay is 100VDC and 40A. To trigger the relay I'd use a simple on/off switch tied to battery power (12vDC).
So what I *thought* was a simple topic turned out into a learning event for yours truly.
Hope this helps (as someone I know likes to say).
Howard
I am going to over engineering this.Yep no surprise there
I am choosing to use the DIN breaker box. https://www.amazon.com/gp/product/B0...?ie=UTF8&psc=1
and miniature DIN rail mount circuit breakers (50a/400V) Brian bertschb recommended https://www.amazon.com/gp/product/B0...?ie=UTF8&psc=1
In my layout this takes up less space overall and is cleaner on the wiring (I think). Yes is costs a bit more, I got to thinking of how close I was to the rated capacity of the switch and the fact that the connections are open on the sides. There is a chance (probably slim) that something could get into the switch and possibly short to ground. Stuff shifts around in the front compartment, and knowing me I would get my finger in their too. I don't need the few hairs I have up top curled. And yes I have the same issue with the other Blue sea switches, or any brand of battery disconnect switches. I have a bunch of spare plastic storage box dividers I may try to use to solve this.
If I ever go with additional panels the PV switches would possibly be overloaded and changing breakers is cheaper. One other advantage I can think of, using the breakers allows you to easily change wire gauges if you have long runs and want to minimize voltage losses. Mount them close to the panels and up size your wire to the solar controller.
A few things I learned in my research. It made my head spin There is no shortage of opinions. You can actually learn a lot if you filter the BS on some sites. And everyone is an expert - well almost.
I learned about the use and properly sizing and the cable glands for my PV wire (provide strain relief) to enter/exit the box. They come in PG designations. I chose the PG21 which takes wire diameters of 13mm to 18mm. Two of my PV cables side by side is 5/8 inch or 15.88mm. I plan to fill the rest of the hole with silicone.
I also learned that one should use DIN rail terminal stopper blocks to keep the miniature breakers from shifting on the DIN rail.
Last no matter what I do - it costs $$$$
Thanks everyone
Keith2018 Reflection 150 Series 220RK 5th whee, Star White 2022 F350 King Ranch CC Long bed (HAL) (CCC 4062lbs), B&W 25K OEM Companion,. SteadyFast system, Trailer reverse lights, rear receiver spare tire holder, storage tube, sumo springs, Victron MultiPlus 12/120/3000, Solar, Custom 6K axles upgrade, and other modifications.
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Yoda
Sounds good. I got a set of those cable glands of various sizes from Amazon for my project, they were handy and I’ve used them since for a few other cable runs. AMSolar’s panel wire they use is a round two conductor so it sits in the cable gland really nicely. No silicone needed.Forum moderators are not GD employees--we are volunteers and owners presumably just like yourself. Unless specifically mentioned otherwise, we have nothing to gain should you choose to purchase a product or engage a service we discuss on this forum.
Neil Citro
2018 Reflection 28BH Pepwave
2019 F350 6.7L Long Bed Crew Cab
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Originally posted by ncitro View PostYoda
Sounds good. I got a set of those cable glands of various sizes from Amazon for my project, they were handy and I’ve used them since for a few other cable runs. AMSolar’s panel wire they use is a round two conductor so it sits in the cable gland really nicely. No silicone needed.2018 Reflection 150 Series 220RK 5th whee, Star White 2022 F350 King Ranch CC Long bed (HAL) (CCC 4062lbs), B&W 25K OEM Companion,. SteadyFast system, Trailer reverse lights, rear receiver spare tire holder, storage tube, sumo springs, Victron MultiPlus 12/120/3000, Solar, Custom 6K axles upgrade, and other modifications.
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Originally posted by Yoda View Post
I wanted to use 8 awg PV cable so had to go separate. The AMsolar round cable is 10AWG and a bit more expensive. Yes overkill again
Forum moderators are not GD employees--we are volunteers and owners presumably just like yourself. Unless specifically mentioned otherwise, we have nothing to gain should you choose to purchase a product or engage a service we discuss on this forum.
Neil Citro
2018 Reflection 28BH Pepwave
2019 F350 6.7L Long Bed Crew Cab
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Originally posted by Yoda View Post
Howard - yes it did help
I am going to over engineering this.Yep no surprise there
I am choosing to use the DIN breaker box. https://www.amazon.com/gp/product/B0...?ie=UTF8&psc=1
and miniature DIN rail mount circuit breakers (50a/400V) Brian bertschb recommended https://www.amazon.com/gp/product/B0...?ie=UTF8&psc=1
In my layout this takes up less space overall and is cleaner on the wiring (I think). Yes is costs a bit more, I got to thinking of how close I was to the rated capacity of the switch and the fact that the connections are open on the sides. There is a chance (probably slim) that something could get into the switch and possibly short to ground. Stuff shifts around in the front compartment, and knowing me I would get my finger in their too. I don't need the few hairs I have up top curled. And yes I have the same issue with the other Blue sea switches, or any brand of battery disconnect switches. I have a bunch of spare plastic storage box dividers I may try to use to solve this.
If I ever go with additional panels the PV switches would possibly be overloaded and changing breakers is cheaper. One other advantage I can think of, using the breakers allows you to easily change wire gauges if you have long runs and want to minimize voltage losses. Mount them close to the panels and up size your wire to the solar controller.
A few things I learned in my research. It made my head spin There is no shortage of opinions. You can actually learn a lot if you filter the BS on some sites. And everyone is an expert - well almost.
I learned about the use and properly sizing and the cable glands for my PV wire (provide strain relief) to enter/exit the box. They come in PG designations. I chose the PG21 which takes wire diameters of 13mm to 18mm. Two of my PV cables side by side is 5/8 inch or 15.88mm. I plan to fill the rest of the hole with silicone.
I also learned that one should use DIN rail terminal stopper blocks to keep the miniature breakers from shifting on the DIN rail.
Last no matter what I do - it costs $$$$
Thanks everyone
Keith
I am in no way an electrical engineer so please take this with a grain of salt,but I would definitely double check the rating of the breaker that you linked to in your message in that the seller does not specify that it is VDC rated. Some reviewers do state that they are successfully using it in a DC/PV application but my pessimistic mind tends to think that everything is fine with their systems working correctly and have not been tested in a short circuit situation. This particular breaker may in fact be DC rated but the exact same breaker is being listed by a different seller as only being AC rated so I would only offer my caution to make sure that whatever breaker you end up using not only meets your Voltage and amperage needs but is also DC current rated.
The video link in this forum thread is what helped me get a better understanding of the bad things that will happen if we get these things wrong.
https://forum.solar-electric.com/dis...ment_396500amp
BrianBrian
2017 Silverado 2500 HD diesel
2018 Reflection 230RL
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Retgw2 -- great post, thank you.
What I get from the linked thread (the author is obviously very knowledgeable) is this takeaway:
If your solar battery bank is grounded to the van <or trailer in our case> frame, then you do not need to have a double pole breaker on the solar array (or the battery output). Just single pole breakers and fuses are fine.
Why? When you negative ground your battery bank, there are no, or almost no, solar charge controllers that have isolation from solar array to the battery bank. So, negative grounding, solar panels are not floating, but ground referenced.
I'd also never given much thought to the ratings of breakers and fuses (AC vs DC). His comment (and the linked video) are convincing!
A simple example of DC vs AC current and DC power to sustain arcs "very nicely" (and why you need to "respect" the DC rating of switches breakers, and fuses on DC circuits, and why AC only rated devices on DC can be dangerous--And why DC rated devices are usually bigger than similar rated AC devices. And why on AC+DC rated devices, the DC ratings for voltage and current are usually much lower than the AC version):
Once more, thanks for asking a "simple" question, Keith and starting this thread. I've learned a lot. ( Yoda ). For my specific system I think it's OK.Forum moderators are not GD employees--we are volunteers and owners presumably just like yourself. Unless specifically mentioned otherwise, we have nothing to gain should you choose to purchase a product or engage a service we discuss on this forum.
2017 Ford F-350 DRW, '19 315RLTSPlus
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Originally posted by Retgw2 View Post
Keith,
I am in no way an electrical engineer so please take this with a grain of salt,but I would definitely double check the rating of the breaker that you linked to in your message in that the seller does not specify that it is VDC rated. Some reviewers do state that they are successfully using it in a DC/PV application but my pessimistic mind tends to think that everything is fine with their systems working correctly and have not been tested in a short circuit situation. This particular breaker may in fact be DC rated but the exact same breaker is being listed by a different seller as only being AC rated so I would only offer my caution to make sure that whatever breaker you end up using not only meets your Voltage and amperage needs but is also DC current rated.
The video link in this forum thread is what helped me get a better understanding of the bad things that will happen if we get these things wrong.
https://forum.solar-electric.com/dis...ment_396500amp
Brian2018 Reflection 150 Series 220RK 5th whee, Star White 2022 F350 King Ranch CC Long bed (HAL) (CCC 4062lbs), B&W 25K OEM Companion,. SteadyFast system, Trailer reverse lights, rear receiver spare tire holder, storage tube, sumo springs, Victron MultiPlus 12/120/3000, Solar, Custom 6K axles upgrade, and other modifications.
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Originally posted by Yoda View Post
Dang it Brian - your correct. Unfortunately its too late to cancel the item - My bad. Now too order the correct ones. This time I will pay more attention to the specifications. If it does not say VDC rated don't get it correct?Brian
2017 Silverado 2500 HD diesel
2018 Reflection 230RL
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Originally posted by Retgw2 View Post
That is my understanding Keith. Make sure that it is DC rated to the voltage and amperage ratings of your system to be on the safe side.
https://www.amazon.com/Low-voltage-M...f_=as_li_ss_tl
https://www.amazon.com/Low-Voltage-M...6952536&sr=8-2
https://www.amazon.com/Low-voltage-M...6952536&sr=8-3
https://www.amazon.com/Miniature-Cir...productDetails
https://www.amazon.com/Low-voltage-M...6&sr=8-16&th=1
Thanks
Keith now back to my corner to sulk
2018 Reflection 150 Series 220RK 5th whee, Star White 2022 F350 King Ranch CC Long bed (HAL) (CCC 4062lbs), B&W 25K OEM Companion,. SteadyFast system, Trailer reverse lights, rear receiver spare tire holder, storage tube, sumo springs, Victron MultiPlus 12/120/3000, Solar, Custom 6K axles upgrade, and other modifications.
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