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Battery Disconnect Switch Recommendations

dsp

dsp

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Jan 10, 2020
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I'm looking for suggestions for a switch between the positive terminal of my battery bank and my inverter.

I have a 200 Amp 48v system configuration running into an MPP Solar LV5048 inverter/controller

Thanks
Don
 
mrdavvv said:
That swith looks a little bit craptacular and i dont see any 48V rating, itll probably work but with that energy i wouldnt trust it.

This are much better and completely trustable:

Click to expand...
Well! I see you're an expert in the field of product marketing...didn't happen to notice that description on the product site

Product spec says the following:
  • Extra Heavy Duty - Rated: 1250 Amps Intermittent, 275 Amps continuous at 12V DC. 2-Position: ON and OFF positions
  • Can be used with 8V up to 60V DC systems to isolate and secure the electrical system
It's a sturdy product and works great. Installed it over the weekend.
 
I have two them, they only handle 60amps without heating up. At 130amps continuous charging from my lv5048 they are getting ready to melt. I will have to replace with another switch, thinking the bluesea..
 

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Mtour said:
I have two them, they only handle 60amps without heating up. At 130amps continuous charging from my lv5048 they are getting ready to melt. I will have to replace with another switch, thinking the bluesea..
Click to expand...
Yeah, I hate it when ads state exorbitant high “intermittent” specs... then go on to say a more realistic amperage but limit to 12V, and give an operating range low to high, but not into the HVDC range...
jumps out as a red herring to me fast.
 
Supervstech said:
Yeah, I hate it when ads state exorbitant high “intermittent” specs... then go on to say a more realistic amperage but limit to 12V, and give an operating range low to high, but not into the HVDC range...
jumps out as a red herring to me fast.
Click to expand...
Yeah I saw that too...but no actual datasheet for either of them, which is what I look for. I figured at sub $25 dollars each, it's a no-brainer to get a different one.

Thks
 
dsp said:
Well! I see you're an expert in the field of product marketing...didn't happen to notice that description on the product site

Product spec says the following:
  • Extra Heavy Duty - Rated: 1250 Amps Intermittent, 275 Amps continuous at 12V DC. 2-Position: ON and OFF positions
  • Can be used with 8V up to 60V DC systems to isolate and secure the electrical system
It's a sturdy product and works great. Installed it over the weekend.
Click to expand...

Lol thats a new one, battery switch shill..., i have been called worse ;).

You are free to purchase any of them, in fact when i was building my own system i happen to consider that same switch between my options... but knowing my limitations and a healthy fear for high amps made me choose the Bluesea option.

I have been dealing with chinese vendors & products for a long time, so i learned to distrust their specs, specially with cheap products (An more when they look that cheaply made in the photos!). I dont have any relation with bluesea, but they been around for decades and their products have UL listings, also they design for one of the worst conditions on earth (the sea!), so i have the bad habit of recomending them for security, against cheap chinese counterparts.

Amazon: $15 USD
Blue sea $25 USD - UL Listed, real specs, very sturdy construction and great quality.

So you are willing to burn your installation for only 10 bucks?. If you were talking about 12V and 50A it will be probably fine, but 48V @200A its a lot more dangerous.

It's a sturdy product and works great. Installed it over the weekend.
Click to expand...

Mtour said:
I have two them, they only handle 60amps without heating up. At 130amps continuous charging from my lv5048 they are getting ready to melt. I will have to replace with another switch, thinking the bluesea..
Click to expand...

I rest my case ??
 
dsp said:
Yeesh you're so full of yourself. Get over it dude

I'm not charging / discharging anywhere near that kind of current. Don't assume you're smarter than everyone around you...I wouldn't blindly connect a switch without considering the spec's

I chose the switch not b/c it was cheap but because it was the only one I could find that supported 60v. I appreciated the tip you gave and would have considered returning it for bluesea but I wasn't able to find one that supported 60v connections.

The one you suggested says:
View attachment 14157


But hey thanks to narcissist know-it-all's like you we're all a little smarter! smh...
Click to expand...

Is the 60VDC rated switch certified by UL, CSA or similar?
 
I've used MANY switches over the decades for DC switching. There are good one and seriously crappy ones and ironically, some of the crappies actually look really good but poor quality materials ruin them.

Over the years I have become pretty dedicated to Blue Sea Switches which are severely tested & abused in every way prior to being made available for sale. Sure they cost more than cheapo's but it' is piece of mind which is priceless.

Bottom Line : IT IS YOUR SAFETY & PROTECTION which includes any Family & Friends which may be risked if you put together something cheap or half-baked. Some people do not want smoke alarms in their homes, others refuse to maintain & change their batteries and then there are others who dutifully maintain, update smoke detectors & their batteries.

BTW: Bashing others for their opinion is UNACCEPTABLE... anyone wanting to do that can feel free to go elsewhere. No one will miss the inputs.
 
I prefer using a heavy-duty UL listed circuit breaker as a manual disconnect switch if I need it.

I hate those large high current switches. Just another part that can fail. I had an expensive one melt in the past, and now I avoid using them entirely.

I have never seen the need for a large manual disconnect switch except for maintenance of system parts, or for grid-tie operation solar input kill switch (required in NEC) for emergency workers.

What is the purpose of these switches for you guys? Just curious.

I prefer most safety/switching functions to be autonomous. And maintenance is very rare in a well-designed system. So I cannot think of a single reason to have these large switches.
 
Will Prowse said:
What is the purpose of these switches for you guys? Just curious.
Click to expand...

Big Red button for when things go wrong.
I would put the switch just after the main battery fuse on the positive leg in places that exceed the capacity of a COTS=common off the shelf breaker.
The bussman breakers I have looked at only go to 200 amps.
Say I make a change to the system and notice that something has gone horribly wrong and my OCP doesn't trip for some reason.
Its my hope that I can open the switch under high current load.
I know thats not guaranteed, but that is the intent.

The other reason is isolation for maintainance.
 
smoothJoey said:
Big Red button for when things go wrong.
I would put the switch just after the main battery fuse on the positive leg in places that exceed the capacity of a COTS=common off the shelf breaker.
The bussman breakers I have looked at only go to 200 amps.
Say I make a change to the system and notice that something has gone horribly wrong and my OCP doesn't trip for some reason.
Its my hope that I can open the switch under high current load.
I know thats not guaranteed, but that is the intent.

The other reason is isolation for maintenance.
Click to expand...
When something goes wrong.. but are you going to be present? Usually solar systems run 24/7. Are you monitoring your system all day?

Right now, both of my systems are running without me monitoring them. If an inverter goes up in smoke, I would not be present. What use is a main switch for "safety" if we are not present for the majority of the time?

Why would your OCPD not trip?

Yes for maintenance, very true. But how often do you do maintenance on a solar power system? Solar input disconnect is very useful for maintenance but a main battery disconnect does not seem very useful. Could just disconnect negative terminal of battery for those instances, as most people do with starter batteries for internal combustion engines. Disconnect negative, then work on the car. I never see people use a main disconnect there.
 
Craig said:
I just use the appropriate circuit breaker as well.
Gladly so because I have many times found out that they work when I inadvertently criss a wire. Usually breakers are about 20 bucks
Click to expand...

Can you or @Will Prowse give examples of DC Breakers for a 48V nominal battery banks? 150A to 200A rating.

I'm also at a cross-road:

I started with an ANL fuse 200A + fuse holder:
aliexpress.com

0.77US $ 4% OFF|ANL/AML Bolt on Fuse/ Fusible Link Fuse/ Auto Fuse / Blade Fuse 30A 35A 40A 50A 60A 70A 80A 100A 125A 150A 175A 250A 400A 500A|Fuses| - AliExpress

Smarter Shopping, Better Living! Aliexpress.com
aliexpress.com aliexpress.com
It worked ok, but above 100A continuous, it got too hot for my liking.

So, I “upgraded” to this 200A Circuit Breaker Car Boat Auto Waterproof:
aliexpress.com

9.88US $ 28% OFF|30a 40a 50a 60a 70a 80a 100a 120a 150a 200a 250a 300a Amp Circuit Breaker Fuse Reset 12-48v Dc Car Boat Auto Waterproof - Fuses - AliExpress

Smarter Shopping, Better Living! Aliexpress.com
aliexpress.com aliexpress.com
Don’t know if it’s defective, or it wasn’t made to handle the ~52V of the battery, or it wasn’t made to withstand more than 50A continuous but, the fact is that it is breaking my DC connection 2 or 3 times a day.

So, what now?
1) Blue Sea 9100E battery switch + ANL 200A fuse, or
Question: the 9100E switch is spec'ed at a maximum 32VDC??

e-Series Selector Battery Switch - Blue Sea Systems

350 Amps continuous rating for inboard gasoline or diesel engines.
www.bluesea.com www.bluesea.com
But people are using them on 48V nominal (~ up to 54V in reality) banks, right?

2) DC Breaker. What make / model? I can only find super expensive ones.


Thanks!
 
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