Resettable Circuit Breaker - Voltage Drop

[cwilken]

I use Bussmann Hi-Amp. Amazon has them.

I have a "48 volt" battery that really goes up to 58 volts. All of the higher quality breaker switches go up to 44v or 48 volts in the self ratings. I prefer one that goes to 60 volts. Some people say they like AC like breakers but I don't know how they mount them without a box and using minimal space. Ive decided to have a separate fuse and battery isolator switch.

 

[time2roll]

I have a "48 volt" battery that really goes up to 58 volts. All of the higher quality breaker switches go up to 44v or 48 volts in the self ratings. I prefer one that goes to 60 volts. Some people say they like AC like breakers but I don't know how they mount them without a box and using minimal space. Ive decided to have a separate fuse and battery isolator switch.

Yes my mind was on the OP 24/3000 victron.

 

[cwilken]

My current favorite surface mount marine grade breaker is Stinger breakers. They are fantastic, and can handle higher voltage than Bussman.

They look pretty well made but I would be very happy to see a video with one of these that is heated up with a 50% amp load for 10 minutes then subjected to a 75% capacity and then a 100% capacity spike. I predict that when they are hot they will throw much lower than advertised!!! Im not really sure these are designed to respond well to constant load situations and still have any accuracy. I just removed my 80 amp breaker switch for a HD battery switch and fuse as my breaker kept going off at low values when it was hot!
Also when I looked at these Stinger breakers I think they only went up to 48 amp. A lot of us who use 48 amp systems are really using 55-60 amp systems so we cant be sure of what can go wrong outside of the called out parameters.

 

[Will Prowse]

They look pretty well made but I would be very happy to see a video with one of these that is heated up with a 50% amp load for 10 minutes then subjected to a 75% capacity and then a 100% capacity spike. I predict that when they are hot they will throw much lower than advertised!!! Im not really sure these are designed to respond well to constant load situations and still have any accuracy. I just removed my 80 amp breaker switch for a HD battery switch and fuse as my breaker kept going off at low values when it was hot!
Also when I looked at these Stinger breakers I think they only went up to 48 amp. A lot of us who use 48 amp systems are really using 55-60 amp systems so we cant be sure of what can go wrong outside of the called out parameters.

No, Stinger has higher amperage models. I am using a 150A model right now. They do not fall apart in high moisture environments unlike other "marine grade" breakers that fail miserably.

Yes, I will test them. I use them on my packs right now 24/7, and they are fine. I will try to pull some certificates and see what their listings are when I get home. I do not understand why people would like a bussman more than a tocas. I think they have the same certificates. I would trust a third party laboratory test more than any personal experience.

 

[Tecnodave]

The one thing that i worry about with Lithium batteries is the available short circuit capacity. The amps are huge at dead short circuit. Really good breakers have a A.I.C. rating....That is not the trip amps, the A.I.C. rating is the Amp Interrupt capability. When that massive dead short happens the current can be very massive, way beyond the trip capability. With a 200 a.h. battery it can be in the thousands of amps. The A.I.C. rating of the breaker must be greater than the maximum amps available. When that unsuspected short happens the entire breaker welds. It is catastrophic. The breaker almost always welds closed.

Do chinese breakers even have a A.I.C. rating? I have never seen a Chinese one that does. They may have one but it is not in the published specs. Well the CBI breakers (Soweto, South Africa) do have a published A.I.C. rating as well as the Schneider and Seimens, (Germany) do but these are industrial rated breakers. It is required in industry as well as breakers for household use, normally 10,000 amps for branch breakers and up to 70,000 amps for main breakers.

It is not required for “car stereo breakers”

 

[Brett V]

The one thing that i worry about with Lithium batteries is the available short circuit capacity. The amps are huge at dead short circuit. Really good breakers have a A.I.C. rating....That is not the trip amps, the A.I.C. rating is the Amp Interrupt capability. When that massive dead short happens the current can be very massive, way beyond the trip capability. With a 200 a.h. battery it can be in the thousands of amps. The A.I.C. rating of the breaker must be greater than the maximum amps available. When that unsuspected short happens the entire breaker welds. It is catastrophic. The breaker almost always welds closed.

Do chinese breakers even have a A.I.C. rating? I have never seen a Chinese one that does. They may have one but it is not in the published specs. Well the CBI breakers (Soweto, South Africa) do have a published A.I.C. rating as well as the Schneider and Seimens, (Germany) do but these are industrial rated breakers. It is required in industry as well as breakers for household use, normally 10,000 amps for branch breakers and up to 70,000 amps for main breakers.

It is not required for “car stereo breakers”

I share your concerns. That's why I put a 300 amp class T fuse just a few inches from the battery and the 200 amp Toca up near the inverter as the first line of defense.

 

[Will Prowse]

Yes, typically AIC for marine breaker is 1500A. Which is fine for a small lithium pack, especially at 12V. That's why they work so well for small systems. Large packs at higher voltage needs T class fuse.

None of these circuit breakers are appropriate when using large current handling conductors with lithium packs. T class is required when using large supply conductors and lithium batteries. Massive current can flow very easily here.

You can also argue that the resistance across the bank of fets will ensure that nothing over 500A will go through it. Even if you short a FET and it doesn't disconnect, a single shorted fet would never allow 1500A through it. So the AIC of the breaker would never be exceeded. Max limit ocp on most bms of a certain time duration that would trip long before a thermal breaker would as well.

I've read that typically the resistance of the cables in a 12V system will ensure that 1500A won't make it to the breaker. Depends on the application though! If you have a massive inverter of any voltage, a t class fuse seems ideal. ANL fuse is fine for 12V inverters as well. But not for 48V inverters.

 

[Will Prowse]

Hi all

Thought I would just share this in case it helps save a little time for anyone else!

I have had problems recently with my Victron Multiplus 24/3000 repeatedly going into low voltage shutdown when driven fairly hard - circa 80 Amps for 2-3 minutes while the washing machine heater is running. Less than 2000 watts, so well within its capabilities.

After much checking and tearing out of non existent hair, it turned out to be the 200A resettable Circuit breaker - 26V input, 16V output, and it wasn't even getting very hot! Once the Multiplus shut down, voltage was restored, washing machine restarted, and the cycle begins again.

I have now replaced the breaker with a 200A mega fuse - problem solved.

I have read before that these cheap circuit breakers are not very good, and I can now agree! Throw them away and get a decent fuse instead ?

Here's the offending article

View attachment 61280

Now replaced with this

View attachment 61281

Max voltage of mega fuse is 32V. Works great for your application, but it would not work for 48V system. Would need t class fuse instead.

AIC of mega fuse is 2000A so you should be good to go for your voltage and if your bank has a BMS. Should interrupt just fine.

 

[Will Prowse]

Stinger Breaker AIC is 5000A at 14VDC, and 3000A at 28VDC!!

• Applications :Typically used in DC power systems in marine applications (as a main or branch circuit breaker), truck and bus systems, RV systems, add-on protection for accessories, lift gates, etc. This unit is external ignition protected and weatherproof.
• Rating : 25-150A, 48Vdc
• Interrupt Rating: Main Breaker Protection Interrupt Rating (5kA@ 14Vdc, 3kA@28Vdc and 1.5kA@ 48Vdc).
• Operating Temperature Rating: –40°F (–40°C) to 185°F (85°C)
• Storage Temperature Rating: –40°F (–40°C) to 260°F (125°C)
• Materials: Black UL-rated 94V0 thermoset plastic body. Cover and lever are UL-rated 94V0 thermoplastic
• Marking: Standard marking includes amp/volt ratings. Custom markings also available

So the circuit breaker I recommended earlier is actually better than a megafuse when it comes to AIC for a 24V system. And it can handle higher voltages. 1500A is typical for 48V breakers as well. In these instances, a main t class fuse would be advisable.

 

[Will Prowse]

Finally found information on the Toca's circuit breaker, but no official data sheet:

Operating Temperature: -32ºC (-25ºF) to 82ºC (180ºF)
Interrupt Capacity:

2,500A @ 14Vdc (25-200A)
1,500A @ 72Vdc (25-200A)
1,500A @ 14Vdc (225A-300A)

Regulatory Specification: SAE J1625; SAE J1171; UL 1500; ABYC E-11; CE; IP67
Termination: 3/8" Stainless Steel Studs
Body: UL-rated 94V0 thermoset plastic
Storage Temperature:-34ºC (-30ºF) to 149ºC (300ºF)

Very typical figures. I like seeing the abyc code, I need to find out what that section means.

 

[JoeHam]

Finally found information on the Toca's circuit breaker, but no official data sheet:



Very typical figures. I like seeing the abyc code, I need to find out what one means.

I had not seen the Toca's information before, thanks for posting.

I think around page 24 starts the pertinent portion of the ABYC stuff here :

http://www.elettronavigare.it/files/E-11%20norme%20americane.pdf

 

[Tecnodave]

On code sets.....

The big standard for buildings in the US there is the NEC.....National Electric Code.. this is written by the NFPA, the National Fire Prevention Association, this is not a government agency ....thus isolated from politics. It goes into many details of the safe way to wire buildings, there are many subsections in there that deal with different areas of electrical use.

The ABYC, The American Boat and Yacht Code, written by the boating industry for the boat and yacht industry but it is not for ships, a very tight code written specifically for pleasure boats, fishing boats, etc. again not a government agency, but solely focused on marine safety not hampered by politics. The AC part of the ABYC closely follows the NEC

And there is the SAE, The Society of Automotive engineers, not a government agency but sponsored by the automotive industry. It relates to that part of a vehicle that moves it down the road including the engine, running lights, charging system

BUT.....Not the coach part of a motorhome or bus conversion!

SAE also governs the trailer lights, brake system , and breakaway system but again NOT the living accommodations of the coach or trailer or camper

That being the case, the solar system including the battery which powers it is governed by the NEC, NOT by the SAE, so therefore the SAE is to be disregarded in the living accommodations of busses, motorhomes and trailers


In a one case comparison of the NEC vs the SAE:

14 gauge wire in the NEC can carry 15 amps
14 guage wire in the SAE can carry 45 amps

AND SAE wire guage is smaller in cross section area than NEC wire!


So obviously the NEC is way more conservative and safety minded than the SAE

Bottom line who wrote these codes...

NEC ...... the National Fire Protection Association
SAE ...... the Society of Automotive Engineers (the automotive Industry)

The NEC is way more conservative for a very good reason......(fire safety)

Personally i use the NEC and the ABYC and largely ignore the SAE directly due to my perceived looseness of the SAE

Here in California the State BAR...the Bureau of Automotive Repair governs only that part of a motorhome or trailer that concerns the running of the vechicle, including the exterior lights, engine, brakes, etc. but NOT the living accommodations, not the power system that is used solely for the living accommodation. You do not need a BAR license to repair the “coachworks” , its considered separately. That is governed by the State Housing Authority....again the electrical is considered housing, not vehicular.

So what i am saying......IGNORE the SAE, use the NEC and refine that on DC systems with input from the ABYC as it deals with DC systems better than the NEC.

 

[Will Prowse]

Yeah I like abyc because it pertains to low voltage DC. Lots of great information for Offgrid solar.

And typically I'm dealing with floating systems so I take only what I need from NEC. I like their max ampacity charts though.

 

[SupraSPL]

Yeap I just tested those cheap 300a breakers and they get hot at 60 to 70 amps with a 2 to 3% voltage drop. Lesson learned

 

[ohiomoto]

I'm using a 50a T Tocas on the output side of my 40 DC/DC charger and seeing a drop of nearly 1 volt at the breaker. So instead of charging at 14.4v, I'm seeing 13.5v. I assume I'll be having the same issue with my Victron 100/30 as it has a 40a Tosca breaker on it.

I assume this means I'll never reach a full charge on my battery (300Ah Enduro Power)?

Any suggestions?

 

[SupraSPL]

Will said Tocas was a decent breaker although they do look exactly the same as my hamolar breakers from Amazon. They have decent reviews too so I dont know whats up. Maybe people are willing to accept a drop like that but wow I hope not.

There definitely shouldn't be a voltage drop that high and it would get very hot (36 watts of heat inside the breaker). Could be a problem with the cable or connectors? If not, I'd return it.

 

[ohiomoto]

I created another thread for this issue but I think I figured out that I was confused by my readings and I don't actually have a problem. Please comment in that thread if you have anything to add.

Thanks.

Charging issue with thermal circuit breaker? SOLVED

I'm using a 50a T Tocas thermal circuit breaker on the output side of my 40 DC/DC charger. I am getting a drop of nearly 1 volt at the breaker. So instead of charging at 14.4v, I'm getting 13.5v max. (I assume I'll be having the same issue with my Victron 100/30 as it has a 40a Tosca breaker on...

diysolarforum.com

 

[Will Prowse]

Can you post a picture here of your meter and the voltage drop figures?

 

[Will Prowse]

I created another thread for this issue but I think I figured out that I was confused by my readings and I don't actually have a problem. Please comment in that thread if you have anything to add.

Thanks.

Charging issue with thermal circuit breaker? SOLVED

I'm using a 50a T Tocas thermal circuit breaker on the output side of my 40 DC/DC charger. I am getting a drop of nearly 1 volt at the breaker. So instead of charging at 14.4v, I'm getting 13.5v max. (I assume I'll be having the same issue with my Victron 100/30 as it has a 40a Tosca breaker on...

diysolarforum.com

Oh ok gotcha.

 

[AkheeBoss]

Yeah I like abyc because it pertains to low voltage DC. Lots of great information for Offgrid solar.

And typically I'm dealing with floating systems so I take only what I need from NEC. I like their max ampacity charts though.

Will Prowes I watched a ton of your videos before deciding to go out and buy a PZE Titan 4000 solar generator. I setup 4 solar panels in series; 2 Rich 200 W and 2 Nature Power 215 W. They generated @ 400 W while pushing a load of (2 friges, TV). After four days the Titan stopped accepting recharge energy from the solar panels (not over 145 V into the mppt ports.) Shipped it to PZE they "repaired" mppt ports, shipped it back to me but unfortunately it still does not accept recharge from the solar panels even though I'm getting 88.1 V directly from the panels. I think the issue is with the DC to DC converter system so I have to ship it back to PZE for another "repair." What do you think Will?

Yeah I like abyc because it pertains to low voltage DC. Lots of great information for Offgrid solar.

And typically I'm dealing with floating systems so I take only what I need from NEC. I like their max ampacity charts though.