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Is this Blue Sea Systems 6007 battery selector / disconnect a no go for a 48V LiFePO4 pack?

howardq99

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As I anxiously wait for my (32) EVE 280Ah cells from Amy, I am gathering equipment for the build-out. I'll have (2) 16S banks and I've purchased a Blue Sea Systems m-6007 Mini Selector Battery Switch (specs here: m-Series Mini Selector Battery Switch) to isolate the banks if needed and use as a disconnect. I'll have a 250A class T fuse protecting each bank but I just noticed that the Blue Sea Switch is only rated for 32V DC max. It's current rating has an intermittent rating of 500A for 5 min and 300A continuous.

I'm good on the current side as I'm not expecting to draw more than 200A max at any given time, but does the 32V rating have any wiggle room? Or is at absolute no go because of the 32V max rating? I'm thinking it's a no go, so what is everyone using for a selector switch at these higher voltages?
 
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I had this same dilemma as you, had been looking at the Blue Sea Systems switch initially for a disconnect/selector on a 48v system.

I instead decided to get an MNDC175-X2 for my 2 banks (16 cells each one, same like you).


I bought a copper flat bar (will bend 90 degree at each end, and make it telescoping in the middle) that I am going to put across the top connector of each 175a breaker to bridge them together (on inverter side), and they will each go to both LV6548 inverters, but turning off the breakers will disconnect them from the respective battery bank (connected off the bottom connector of each breaker). I also wanted this kind of box because it allows to add in two rows of other DC breakers to run other native DC 48v loads.
 
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Do remember that a 48V LiFePO4 battery means close to 57V at times. That's 178% of the switch's rated voltage. I wouldn't even consider it.
 
While I share your concern, the switches are also rated at 350A continuous @ 48v, which means they are built very well and will handle higher voltage at lower amperage (he mentioned only 200a draw, which split between the two batteries for most of the time would be 100A) to some extent.

In addition, there is no 4x12v battery system out there in the world that would only be 48v all the time. At minimum the company would have built it to withstand 55v for a 48v system, and probably 60v I would guess.

While this is speculation entirely, I think it's a pretty safe bet.

There are PLEANTY of battery switches out there that say they are rated for 60vdc that I wouldn't touch with a 10' pole. Blue Sea Systems switches are far superior to any of those.
 
I would contact Blue Sea Systems and ask. Then you'll know for sure. Post what you hear from them.

But I would think a 32V switch is only meant or 12V or 24V systems.

the switches are also rated at 350A continuous @ 48v
Where is this documented? I only see the specification stating the maximum voltage is 32VDC.
 
Most modern (larger) marine applications are 24 volts, 32 and 36 volt systems were used in the 1930’s thru the 1950’s but that is history. The Jacobs wind generators of the 1930’s thru the 1950’s were 32 or 36 volts DC. Nobody uses 32 & 36 volt systems anymore and there are no marine applications that are 48 volts DC. Schneider electric does make DC breakers in the 48 volt to 120 volt DC range, but mostly at their european factories. Schneider’s Square D division does market the QO line which is rated 48 volts DC but they are not suitable for 48 volt systems. There are old stock QO breakers around that were UL listed at 72 volts dc but Square D changed the standard some 20-25 years ago and no longer certifies their QO line at 72 volts.

Bottom line.....Square D QO line breakers are well suited for 24 volt systems and are safe to use in any 24 volt DC systems as the voltage “should not” go above 32 volts DC

Way less expensive than some others.

Personally Im using Midnight Solar MNDC Breakers which are manufactured by Carlingswitch (D-series) rated 150volts DC and 120 volts AC and Midnight MNEPV series which are rated 150 volts DC (U.S. ETL cert. ), manufactured by CBI, Circuit Breaker International , Sweto, South Africa 120 volts DC (Euro and africa cert)

boB Gudgel @ Midnight Solar had them recertified by ETL for the higher voltages

BTW......Boeing uses Carlingswitch in their aircraft........
 
Where is this documented? I only see the specification stating the maximum voltage is 32VDC.
I was talking about the switch I recommended, not the one he had. The 9003e is rated for 48v, not the m6007 he has. I entirely agree I wouldn't run the one rated for 32v on a 48v system. Sorry, I should have caught that when you said 178% of capacity.
 
I would contact Blue Sea Systems and ask. Then you'll know for sure. Post what you hear from them.

But I would think a 32V switch is only meant or 12V or 24V systems.


Where is this documented? I only see the specification stating the maximum voltage is 32VDC.
I have confirmed the Blue Seas rating for their breakers....it is 32 volts DC maximum
 
This thread:


makes it clear that the Blue Sea switch shouldn't be used for 48V systems. There are several other threads about this too.
 
BTW.......Blue Seas breakers are Carlingswitch and most are rated 120 or 150 volts DC, Blue Seas rebrands several Carlingswitch lines at least the “A, C, and D series which still carry the UL listings as they are not changed
 
Thanks for all the input!

I think I'll use 2 of those 9003e switches, not as elegant as just using 1 selector switch but it should work fine with the voltages on a 48V LiFePO4 battery. Just to be safe I'll call Blue Sea in the morning and ask them for their recommendation.

I've already got a Noark 250A 2P DC circuit breaker (EX9MD2-B) and this thing is HUGE! I am going to place it after a Victron Lynx Power In...
 
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So I reached out to Blue Sea Systems and here was their response...

Our battery switches have a 48-volt Maximum rating. So typically, 12, 24- & 36-volt systems that would never exceed 48 volts. Our switches are not rated for 48-volt systems that will reach near 60 volts in some cases. That would be well over the max we have been approved for by the UL Listing we have been certified for.

Whistle blown, red card comes out.... Blue Sea battery switch is ejected from the game!
 
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Our battery switches have a 48-volt Maximum rating. So typically, 12, 24- & 36-volt systems that would never exceed 48 volts. Our switches are not rated for 48-volt systems that will reach near 60 volts in some cases. That would be well over the max we have been approved for by the UL Listing we have been certified for. Are they just worried about legal liability when they say this? They may work, but are not certified, so they HAVE TO say that?
 
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