MCCB? I have a NOARK 250A MCCB and have to try to create my own mounting bracket for it... hence the reason I am always interested in any of these breakers AND how people are actually getting them mounted.
Blue Sea Battery Switch for 48v Systems?
- Thread starter KalebTheMaker
- Start date
Hedges
I See Electromagnetic Fields!
- Joined
- Mar 28, 2020
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- 20,688
This document, for 600A switch, says Voltage Max Operating 32V (so I think it is meant for 24V system)
This 300A switch, Maximum Voltage Rating 48V
It can isolate, but not interrupt current (of course not, isn't spring-loaded snap action)
"Operation
• Turn all appliances off before turning the battery switch to OFF.
• Do not switch to OFF while engine is running."
I don't see any reason why either would not hold off 60VDC just fine, insulation would not break down and it wouldn't arc (below Paschen voltage for any gas.)
But maybe greater distance is desired for "creepage" in dirty environment.
Why one is 32V and other is 48V, when not rated for load-break, I don't know. Maybe it can successfully break load a limited number of times.
Higher voltage would be considered human safety risk. But standing in salt water, I wouldn't want to touch 48V either.
timselectric
If I can do it, you can do it.
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- Feb 5, 2022
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Nader breakers are MCB's (Miniature Circuit Breaker).
They mount on a standard din rail. Or in a standard din rail enclosure.
KalebTheMaker
New Member
Hi all, thanks for the conversation!
I just got off the phone with a BlueSea and asked if he could explain this to me. He was very helpful and here is what he told me:
These M-Series switches are designed for 12-36v systems, the sweep style contacts have about 2mm of distance between them, and at 48v (closer to 56v in charge state) it can easily create an arc, and the arc has been known to stay. He stressed that it may not break the circuit 100% of the time (which we need in a battery cut-off switch) as the arc will pass the voltage.
They are working on a switch that is rated for 48v systems, but it is not available yet. They are also considering changing the labeling on these products to say something like 46v so people are not confused and use them on a 48v system.
From that information, and the information provided by you all, I will not be using these even though it is going to delay my startup date while I try to figure out what the correct switches are.
Thanks all,
-Kaleb
I just got off the phone with a BlueSea and asked if he could explain this to me. He was very helpful and here is what he told me:
These M-Series switches are designed for 12-36v systems, the sweep style contacts have about 2mm of distance between them, and at 48v (closer to 56v in charge state) it can easily create an arc, and the arc has been known to stay. He stressed that it may not break the circuit 100% of the time (which we need in a battery cut-off switch) as the arc will pass the voltage.
They are working on a switch that is rated for 48v systems, but it is not available yet. They are also considering changing the labeling on these products to say something like 46v so people are not confused and use them on a 48v system.
From that information, and the information provided by you all, I will not be using these even though it is going to delay my startup date while I try to figure out what the correct switches are.
Thanks all,
-Kaleb
Thanks for the followup! Very informative. Does make me wonder how many of these switches are really rated for 48V nominal systems. The BEP one was mentioned as okay to use but wonder if the design is really that different or is also unsafe to use even though someone has mentioned they said it was. I think it is safer to go by what the actual publicized ratings are. The Nader breakers @timselectric is using seems like they may be good option if you are staying below that amperage level.. Can order 100A and 125A directly from them: https://www.sourceasi.com/product-c...reakers/ul1077-high-current-circuit-breakers/
KalebTheMaker
New Member
The final solution to this was to use the Victron switches. I was told they are *actually* rated for 48v systems. Much more affordable solution, I was looking at 250A Midnight breakers that were $110/each and they want about that much for the enclosure for them as well. To go the Midnight Breaker route for the three breakers and two enclosures was over $600. Victron switches are ~$36.00/each.
I will also make sure that my shutdown procedure includes hitting the main AC breaker to disconnect any loads before I go for the battery switches. They are in close proximity, so in an emergency, it should not be a problem.
Getting close, I should be able to fire up my system as soon as the switches arrive!
I will also make sure that my shutdown procedure includes hitting the main AC breaker to disconnect any loads before I go for the battery switches. They are in close proximity, so in an emergency, it should not be a problem.
Getting close, I should be able to fire up my system as soon as the switches arrive!
Who told you that? Everything I see related to it still states "48V" without actually specifying what that means.. especially when even a 48V "nominal" system differs in how high voltage goes depending on if you are using LiFePO4 or Pb so you technically really need this spec precisely defined (which Victron does not). I realize even Victron shows using those switches in their schematics but I don't see anything that provides arc suppression. Without that you can easily create an arc if you don't turn that rotary switch fast enough. That is why in the Midnite breaker for instance there is a very quick spring loaded flip to break the connection once you push the lever far enough. The IMO PV disconnect switches also have that very fast disconnection that happens irregardless how slowly you turn the knob (not for use with batteries but showing that other manufacturers know what is required to break the DC connection especially under load).
Also interesting to note that Victron DOES specify the maximum voltage on their busbars https://www.victronenergy.com/upload/documents/Datasheet-Busbar-600-A-EN.pdf
So I think they are purposely not specifying that for the switches because it really isn't rated for breaking a 48V system under load and they have the backup of anyone that does have issues that it is not specified anywhere to be rated for anything above 48V.
So I think they are purposely not specifying that for the switches because it really isn't rated for breaking a 48V system under load and they have the backup of anyone that does have issues that it is not specified anywhere to be rated for anything above 48V.
KalebTheMaker
New Member
My sales rep, he told me he spoke to Victron to confirm. So, I guess I am going off of that. I do not have a spec sheet that shows me for sure. I am leaning toward trusting him because ill get the Victron switches essentially free once the blue sea switches are returned. Getting into the Midnight switches is around $600 which I just can't do right now. I purchased this equipment several months ago and am now just getting to installing it. If I would have known during the spec, I *probably* could have afforded that set of breakers.
Also, I have been off-grid since September with no refrigeration, and I am seriously in need of having fresh foods, being able to meal prep, and store food. So I am very anxious to get this running.
So far, the only other option I have seen is the Midnight solution for 48+v, 250A. And it's just too expensive. Maybe once I get this done, shop built and can work again, I can afford the midnight breakers. But until then, I will just have to be very careful when I do full disconnects. Hopefully, that will not be very often. And from what I understand, the only issue with the blue sea switches is during the actuation of the switch. In either position itself, it can handle the voltage and the load.
DIYrich
Solar Wizard
I gave up on a switch. I use the bms to turn the battery on and off.
DIYrich
Solar Wizard
Yes, class t.
Blues sea senior tech Kevin ( a smart guy) told me when buying 6 of their 350 amp switches they were Not to be operated under load … and if you somehow get a signifigant arc flash when using them. to replace it ASAP .it’s contacts get damaged and will be worse next time.. that was for the big 100.00 dollar Grey one that’s the size of a small pound cake.
I use IMO…. It’s good ….it’s fast….only about a hundred bucks ….about 4ms contact break time.?
I had a boat years ago and I went through several disconnect switches for my inverter e which could peak at 400 amps. This was a marine environment but every switch I tried (including Blue Sea) had too much resistance. I simply ran it through a 400 amp T class fuse and hung a wrench near by for leisure disconnect and a cable cutter for emergencys. Now Watts247 sells a breaker that I use and trust in my house.
davedigerati
New Member
Guys, at least as of today Victron sells a switch for 48V systems rated to switching under load 60V, check out my full post here: https://diysolarforum.com/threads/battery-disconnect-for-nominal-48v-systems.32915/post-1006489