Blue Sea Add a Battery

[jeremyjohnolson]

I made this plan of how I am going to set up the Blue Sea add a battery in my Tige 2004 20v Switch. Can someone please look at it and tell me if they think everything looks good or of there is anything wrong in my plan? Thanks!

 

[alldodge]

It looks ok
Your setting it up to charge the house Bats first

 

[jeremyjohnolson]

It looks ok
Your setting it up to charge the house Bats first

Yes, I was told by Blue Sea tech support that it's best to charge the house battery first because it will be the battery that drains more often. The start battery will only be used once when starting.

Is it OK to go without the two 150 amp fuses between the batteries and ARC? I read in another forum a guy said he was going to do that because the ARC as protections built in where it will fry in the event of a short to ground and then you just replace the ARC in the unlikely event that happens instead of fusing it. Given the likelihood of that happening (low) and the cost of the 150 amp fuses, I am thinking I might just forego the fuses.

 

[alldodge]

I have only one installed on one side. If something happens it will blow, and I'm using a breaker

I also charge the start bat first because the house is not used that much. Would rather make sure its charged over the house. That said if I used the house side more, and had more then one house bat I would do it your way.

 

[Bob Sander]

Is it OK to go without the two 150 amp fuses between the batteries and ARC?

Not really, no.

Contrary to popular belief, fuses are actually included in circuits not to protect the device(s) you may have connected, but rather the wiring which makes those connections. In the case of a short you want the fuse to blow instead of turning the wiring into a large heating element and causing a fire.

Further, All (main) fuses should be located as closely as possible to the power source (the battery or starter as example) since any wiring between the battery and the fuse is unprotected.

Any wiring used must have an amp rating of at least as large as the fuse you are using. In other words (as an extreme example) there is no sense connecting 18 gauge wiring to a 150 amp fuse. The wiring would burn and possibly set fire to something up before the fuse ever pops.

 

[sam am I]

Not really, no.

Contrary to popular belief, fuses are actually included in circuits not to protect the device(s) you may have connected, but rather the wiring which makes those connections.

Well, have to disagree with ya in some respects as it can depend..........

A jammed motor (although not electrically "connected") not turning the windings heat up and the enamel can cook shorting the windings together, if current is limited/stopped by a fuse opening, the motor(the device) is potentially kept from being destroyed.

What if in the above case the jam is caused by a *person being caught in the motor? Like an electric window/door and such..... The fuse/breaker opening due to over current AND stopping the motor before perhaps more severe injuries could occur.

If *puppy is chewing on the live extension cord, when he chews the two conductors together, the short's point of contact only makes a "smaller" more controlled limited current arc in his mouth instead of a GIANT exploding sustained 3000A welding arc, thus saving puppy's (the device) life from the more severe injuries/burns.......

Happens for people too(the device!!), esp. so with GFI interrupts, if a body gets between hot and ground(or puppy laying on concrete floor[gnd] and chews on hot) , only uA of current are allowed flow for mS through the person's body,

And breakers and GFI are by all rights, a **fuse as well.

In above cases, sure, the wire didn't melt and catch fire, BUT the devices were also better protected/saved, yes?

*NO animals or people were harmed in the making of this example, the examples were of and for demonstration purposes only.

**The definition of a fuse is an electrical safety device that can stop current from flowing if it becomes overloaded.

 

[Bob Sander]

Well, have to disagree with ya in some respects as it can depend..........

A jammed motor not turning the windings heat up and the enamel can cook shorting the windings together, if current is limited/stopped by a fuse opening, the motor(the device) is potentially kept from being destroyed.

Well, small and mid sized motors have their own internal thermal overload protection. With larger motors you are SUPPOSED to wire in a combo motor contactor/breaker. Of course a lot of people don't include those in their circuits and instead rely on the (false idea) of a breaker as a form of device protection.
Every device is supposed to have its own protection devices built in, or at least wired to some protection device regardless of the fuse/breaker which is there to protect the wiring. Any store bought device... microwave, tv, stove... etc, will have its own protective fuse built in somewhere. The fact that some people wire in motors and rely on the branch circuit breaker as protection for that motor doesn't make it proper, or change the main function of that circuit breaker.

Look at it this way, when you plug something into your home outlet do you run downstairs and change the breaker out to a more appropriate size to fit the device in question? Of course not, because the breaker is sized for the wiring being used because it is there to protect that wiring, not the device. The device is SUPPOSED to have its own protection.

 

[sam am I]

The device is SUPPOSED to have its own protection.

Not all motors have them and if this is the case and the fuse doesn't limited current, the overheating device (the motor) can be the cause of fire, not the wires.

Yes and that supposed protection is typically a fuse, by which, can and will protect the device from catching fire/dying, not the wiring..........

So this is the point, not all fuses/breakers(current limting devices) are of the sole purpose to protect the wiring (although it can) as not all wiring is gauged in designs and load failures are such that the given gauged wiring will be overheating catching fire, some devices themself can be the cause of the fire/be injured (consider intrinsically safe designs as one example), as THOSE fuses (internal or external) "included in circuits" can ALSO serve the purpose to protect the device(person, motor, radio, microwave) from being the causation.

Your statement of "fuses are actually included in circuits not to protect the device(s) you may have connected" isn't entirely accurate.

 

[Bob Sander]

Not all motors have them and if this is the case and the fuse doesn't limited current, the overheating device (the motor) can be the cause of fire, not the wires.

Yes and that supposed protection is typically a fuse, by which, can and will protect the device from catching fire/dying, not the wiring..........

Most if not all motors you will find in your house, including hair dryers, heating pumps, sump pumps, a/c compressors... etc, are already thermally protected. They shut down in case of overheating. There is thermal protection woven right into the coils


Of the motors that don't (mostly the bigger multi phase) you are SUPPOSED to be including it in your wiring configuration. Now that's not to say that all do, but because people are trying to save money doesn't change the theory behind branch circuit breakers.

And yes... wiring is SUPPOSED to be sized according to the breaker. NEC regulation as example, you can't place 14/2 cable on a 20 amp breaker. 14/2 cable works on a 15 amp breaker. Inspector will red tag you if he sees 14/2 on a 20 amp breaker.

Now with low voltage wiring all bets are off. It's like the wild west of wiring because there is really no universal set rule or standard... which is why threads like this come to life!

 

[sam am I]

thermally protected. They shut down in case of overheating. There is thermal protection woven right into the coils

By "shut down" you mean their internal fuse opened? And they are over thermaling because of too much load current, and too much load current is being limited/stopped by said thermal cutoff, and a thermal cutoff is by definition is a fuse?

So, these fuses are ALSO protecting the motor from perhaps catching fire, not the wiring.......My point and again, your statement of "fuses are actually included in circuits not to protect the device(s) you may have connected" isn't entirely accurate.

Now with low voltage wiring all bets are off. It's like the wild west of wiring because there is really no universal set rule or standard... which is why threads like this come to life!

You've focused primarily on residential AC (and motors which you yourself have shown have thermal fuses that can also, and are primarily used/intended to protect the motor, not the wiring).

Yes, you're neglecting an entire other realm of issues and designs both AC and DC, low and high voltage that exist in the real world. I've listed only but a few examples above where fuses(all types) are designed and intended to ALSO protect the device, not JUST the wiring contrary to your original statement in post #5 and re-quoted in post #8.

I believe this has been exhausted several posts ago....

 

[poconojoe]

Well, have to disagree with ya in some respects as it can depend..........

A jammed motor (although not electrically "connected") not turning the windings heat up and the enamel can cook shorting the windings together, if current is limited/stopped by a fuse opening, the motor(the device) is potentially kept from being destroyed.

What if in the above case the jam is caused by a *person being caught in the motor? Like an electric window/door and such..... The fuse/breaker opening due to over current AND stopping the motor before perhaps more severe injuries could occur.

If *puppy is chewing on the live extension cord, when he chews the two conductors together, the short's point of contact only makes a "smaller" more controlled limited current arc in his mouth instead of a GIANT exploding sustained 3000A welding arc, thus saving puppy's (the device) life from the more severe injuries/burns.......

Happens for people too(the device!!), esp. so with GFI interrupts, if a body gets between hot and ground(or puppy laying on concrete floor[gnd] and chews on hot) , only uA of current are allowed flow for mS through the person's body,

And breakers and GFI are by all rights, a **fuse as well.

In above cases, sure, the wire didn't melt and catch fire, BUT the devices were also better protected/saved, yes?

*NO animals or people were harmed in the making of this example, the examples were of and for demonstration purposes only.

**The definition of a fuse is an electrical safety device that can stop current from flowing if it becomes overloaded.

You are missing the point that the wire feeding the device is supposed to be sized correctly for the load of the device. The fuse or breaker, if properly sized, not only protects the wiring for overloads or shorts, but also the device.

I would never feed a 100 watt light fixture with a 500 mcm cable that is protected by a 400 amp breaker. Just as much as I wouldn't feed a 200 amp house service with 14 gauge wire and a 15 amp breaker.

Also:
A GFCI is not an over current protection device. It's not the same as a fuse or circuit breaker.

Stick to your own profession, whatever that may be.

 

[Bob Sander]

By "shut down" you mean their internal fuse opened? And they are over thermaling because of too much load current, and too much load current is being limited/stopped by said thermal cutoff, and a thermal cutoff is by definition is a fuse?

They are double acting bimetallic switches. They can be triggered by BOTH too much current or heat generated by the coil. So yes... they are both a fuse and thermal protector. Some are self resetting and some are one time beasts which must be replaced when they go.

So, these fuses are ALSO protecting the motor from perhaps catching fire, not the wiring.......My point and again, your statement of "fuses are actually included in circuits not to protect the device(s) you may have connected" isn't entirely accurate.

You are now taking what I have said out of context... but I think you knopw that. The BRANCH FUSE/BREAKER is to protect the wiring. How one chooses to internally protect their product... internal fuse, internal breaker... etc, can be of many different designs... including fuses. What you have neglected to see or read apparently is that I said just EXACTLY that in post #7:

Every device is supposed to have its own protection devices built in, or at least wired to some protection device regardless of the fuse/breaker which is there to protect the wiring. Any store bought device... microwave, tv, stove... etc, will have its own protective fuse built in somewhere. The fact that some people wire in motors and rely on the branch circuit breaker as protection for that motor doesn't make it proper, or change the main function of that circuit breaker.

You then went on to say in post 8 that not all motors have them. That logically suggests that you are back talking about the branch breaker as a device protector.

Forgive me but it appears you're now kind of spinning your wheels and changing your story with every other post. Either that or you can't read... either way though, I have lost interest in trying to hammer the idea through.

 

[sam am I]

Stick to your own profession, whatever that may be.

LOL, got ya and now I know where your limits were exhausted as well, this is fine......Stating that "fuses are actually included in circuits not to protect the device(s) you may have connected"(which is what the point if you're following and not being sidelined by a baffling back peddling amount of incoherent info) is quite ignorant to say the least, in which we all now that this isn't always the case, but we're all entitled to our opinion and if that's yours as well, so be it.

 

[alldodge]

Come on guys, lets let this one go to bed

 

[poconojoe]

.....Stating that "fuses are actually included in circuits not to protect the device(s) you may have connected"

You have mistaken me for someone else. I did not state that.

Over current devices are meant to protect both the wiring AND the load. But....the wiring must be sized according to the load and that is all engineered by the manufacturer.

The over current device protects the load device as much as the wiring, that's all I'm saying. It's not there to only protect the wiring.

If you had a load drawing 10 amps, you could feed it with 10 gauge 30 amp rated wire, but you had better fuse it according to the load of 10 amps, not according to the 30 amp rating of the wire.

 

[sam am I]

You have mistaken me for someone else. I did not state that.

Fair enough and my mistake as my impression initially was you were of the volition that "fuses are actually included in circuits not to protect the device(s) you may have connected, but rather the wiring which makes those connections"

Over current devices are meant to protect both the wiring AND the load.

There are cases/designs where main feed fuse rating(total current) can be larger than say a circuits components limit (wattage) to where in a failure mode, the current(not the main feed) in the device is such that it can flame up, BUT the main fuse still conducts.....THIS fuse is protect the device, not wires.

Again, consider intrinsic safety designs where the fuse is protecting the components from causation

The over current device protects the load device as much as the wiring, that's all I'm saying.

Agreed

It's not there to only protect the wiring.

Agreed

 

[poconojoe]

Fair enough and my mistake as my impression intially was you were of the volition that "fuses were only included not to protect devices but to protect wires"



There are cases/designs where main feed fuse rating(total current) can be larger than say a circuits components limit (wattage) to where in a failure mode, the current(not the main feed) in the device is such that it can flame up, BUT the main fuse still conducts.....THIS fuse is protect the device, not wires.

Again, consider intrinsic safety designs where the fuse is protecting the components from causation



Agreed


Agreed

No problem.
Thanks for clearing that up.
You are indeed the knowledgeable gentleman I always thought you were!

 

[Bob Sander]

More info on the subject for the nay sayers. If you still have problem wrapping your head around this then there is nothing more I can do for ya.

Steven J Greenfield
, Studying electricity and electronics from a young age. EET degree.
Updated 2 years ago · Author has 3.4K answers and 10.3M answer views


It is a common misconception that fuses and circuit breakers protect the equipment. But generally by the time a circuit breaker or fuse pops, it is blowing because the equipment or device has already failed.

Fuses and circuit breakers are there to open up the circuit when currents much higher than expected are flowing. The reason for this is to prevent a fire, and also to prevent injury to people. Devices that are not double-insulated must be grounded, so that if live electricity shorts to the exposed metal parts, the case will not go live and the fuse or breaker will blow, removing power.

A circuit breaker and the wire and outlets connected to it are rated to be perfectly safe when drawing the maximum current, with a safety margin. So for instance if the breaker is 15A, the wiring must be sized to not heat up excessively at 15A and up to some safety margin above that, and the outlet must also be built to be safe to some safety margin above 15A.

Then if something fails and draws more than 15A, the breaker opens up, preventing the wire in your walls and your outlet from getting hot and starting a fire.

Fuses are used inside electronic equipment so that they don’t have to design all wiring inside a TV, for instance, to be safe to 15A with a safety margin. Instead, it may have a 3A fuse and then the wiring is safe to 3A with a safety margin.

Also, something like a TV or stereo without a fuse might draw 5 to 10A when it fails and start burning, but the breaker would not open up.

But a TV that normally draws 1A that has a 3A fuse is not going to be saved by the fuse. Because in order to draw more than 3A, it must have already failed.

In motorized devices, fuses are not normally used because motors draw a lot more current on startup. In that case, a small-ish motor may have a built-in circuit breaker that could be manual reset or autoreset.

What is the purpose of fuses and circuit breakers?

Answer (1 of 29): Fuses and Circuit Breakers (CB) are used for the protection of power system. These along with other protective equipment like relays, isolater, switches, are collectively called as switchgear(switching equipment used in power systems). The basic function is to break the circuit...

www.quora.com

 

[bruceb58]

My 2017 Cobalt came with the Blue Sea ACR. The ACR is connected at the battery switch. The leads from the switch to the ACR are less than a foot each. No fuses. There is no ground metal near the switch or the ACR.

The battery cables that come up to the switch are 2/0. I will have to look to see what the size wires are that go to the ACR. No fuses on those either 2/0 battery cable obviously since they can be used to start the engine.

The reality of using this is that the ACR will never connect two batteries if one of the batteries is below 9.5V. Even if one battery is at that 9.5V and the other battery has the alternator voltage, a wire as little as 10AWG would not melt since you would have so much voltage drop occurring, that the current would naturally be limited.

 

[Bob Sander]

My 2017 Cobalt came with the Blue Sea ACR. The ACR is connected at the battery switch. The leads from the switch to the ACR are less than a foot each. No fuses. There is no ground metal near the switch or the ACR.

The battery cables that come up to the switch are 2/0. I will have to look to see what the size wires are that go to the ACR. No fuses on those either 2/0 battery cable obviously since they can be used to start the engine.

The reality of using this is that the ACR will never connect two batteries if one of the batteries is below 9.5V. Even if one battery is at that 9.5V and the other battery has the alternator voltage, a wire as little as 10AWG would not melt since you would have so much voltage drop occurring, that the current would naturally be limited.

Correct. There is some (low voltage) wire which is not fused/breakered, and that is a highly debated topic... and it's exactly what I mean when I say low voltage is the wild west of wiring.
I have a 10,500 lb winch on my jeep and the winch came with its own circuit breaker included in the box. If you get a winch made by Warn however, you will not be supplied with a breaker, or any other kind of protection, because they do not recommend use of a fuse or circuit breaker on their winches. Now one can argue whether their rule is better for you..... or for them. They don't have to field as many warranty calls because circuit breakers on larger amperage devices like starter motors or winches is a real pain in the azz and are almost always clicking out at the wrong time. On the other hand, it's an obvious increased fire hazard for you.... albeit at an added convenience in not having to deal with a breaker falsely popping on you all the time. It's like that smoke detector located near your shower on the second floor. It's an F'n p*iss-off most of the time... and hopefully.... that's all it will ever be to you.

You can bet though that if safety regulation came down the road on low voltage wiring the same way it is for household wiring, we along with Warn would no longer have the (convenient) choice of excluding the fuse/breaker in ANY circuit.

The point is though... fuses are safety devices built to protect the wiring. They were not built to increase efficiency, or be even noticeable in any other way. This of course means you can most certainly do without them in your circuit... but with that, you are automatically less protected in the case of failure.