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Fuses are a vital piece of safety equipment in any electrical system. Fuses protect the wire from an overcurrent event such as an electrical short or from trying to push too much power through too small of a wire. This blog post will teach you what type of fuse you need for your DIY camper electrical install.
Cheap vs Expensive Fuses
In the past, I’ve recommended very inexpensive fuses. They worked for a while and many people had good luck with them. Recently (since February 2020), both myself and the tech support team at Battle Born Batteries who I work closely with have seen an increasing number of quality control issues on these non-name-brand fuses that are so common on Amazon. These problems revolve largely around the fuse getting too hot under normal use. This would cause the fuse holder to melt, loosen, and cause the system to stop working.
So… if you wish to save some money and test your luck with these inexpensive fuses and fuse holders; that is your prerogative; but I can no longer recommend “no-name” fuses and fuse holders on EXPLORIST.life. So, the following list will include only fuses and holders from Blue Sea, Littelfuse, Bussman, Eaton, Spartan Power or similar that have, at least some kind of testing agency certification or code compliancy recognition (UL, ABYC, ROhS, etc).
How Big of a Fuse do I Need for [My Device]
This blog post is more about the various TYPES of fuses and not necessarily how to choose the sizes. If you want a more in-depth blog post & video that will teach you how to size a fuse, you can click here for the specific blog post on that topic: https://www.explorist.life/what-size-fuses-to-use-for-a-diy-camper-electrical-setup/
Best Fuses & Fuse Holders for a DIY Camper Electrical Install
This list will show you the various types of fuses you will encounter during your DIY camper electrical install and teach you which ones are right for what purposes.
ANL fuses come in various sizes from 40A to 750A and have a max voltage of 32V (DC voltage only). These are good for any bigger loads such as Inverters, charge controllers, power distribution panels, or even as the main battery fuse. These fuses mount inside of an ANL Fuse Holder.
Use these fuses:
- ANL Fuses are recommended by the Manufacturer.
- Between the Battery Bank & main DC Distribution (Lynx Distributor or Busbars)
- To protect the DC wire going to an inverter
- To protect the DC wire going to a solar charge controller from the battery bank/busbars/distribution.
- To protect the DC wire going to your fuse block for branch circuits.
Do NOT use these fuses:
- Circuits with AC voltage
- Circuits with DC voltage exceeding the max voltage of the fuse.
MEGA fuses come in various sizes from 60A to 500A and have a max voltage of 32V - 70V (DC voltage only) depending on the model. These are good for any bigger loads such as Inverters, charge controllers or power distribution panels. These fuses mount inside of an MEGA fuse holder.
Use these fuses:
- When MEGA Fuses are recommended by the Manufacturer.
- Inside of a Victron Lynx Distributor
- To protect the DC wire going to an inverter
- To protect the DC wire going to a solar charge controller from the battery bank/busbars/distribution.
- To protect the DC wire going to your fuse block for branch circuits.
Do NOT use these fuses:
- Circuits with AC voltage
- Circuits with DC voltage exceeding the max voltage of the fuse.
The Victron Lynx Distributor is 4x MEGA fuse holder in one. This is a PERFECT solution for dividing up and protecting your circuits for your high amperage drawing devices such as an Inverter/Charger, Charge Controller, DC power distribution panel for branch circuits, alternator charging, etc.
This device is essentially a positive and negative busbar with 4 fuse holders all contained in one nice and neat package.
Class T fuses are recommended by certain Inverter manufacturers. If the Inverter you have chosen to use requires this type of fuse, this is the fuse you are looking for. These fuses are rated up to 125V DC.
Use these fuses:
- If the manufacturer of a specific component suggests it.
Do NOT use these fuses:
- Circuits with AC voltage
- Circuits with DC voltage exceeding the max voltage of the fuse.
If you have a device that requires use of a Class T Fuse, this holder is where you will mount the Class T Fuse.
These fuses mount into a fuse holder that is designed to mount directly to a positive battery terminal. Unlike many of the other fuses which require a wire to go between the battery terminal and the fuse holder, this is a nice space saving option if it will fit in your particular battery space. These have a max voltage of 58V and come in various sizes from 40A to 300A.
Use these fuses:
- When you need to connect a fuse directly to a positive battery terminal.
- To protect the wire going from the starting battery to a DC DC charger or Isolator
Do NOT use these fuses:
- Circuits with AC voltage
- Circuits with DC voltage exceeding the max voltage of the fuse.
- Circuits requiring a fuse larger or smaller than the max parameters of the fuse.
Blade fuses are common for protecting the wires going to the low-amperage branch circuits in your camper like lights, fans, usb outlets, refrigerators, etc; and are contained in a fuse block or DC distribution panel.
Use these fuses:
- When Blade Fuses are recommended by the Manufacturer.
- In 12V distribution panels or fuse blocks
Do NOT use these fuses:
- Circuits with AC voltage
- Circuits with DC voltage exceeding the max voltage of the fuse.
- Circuits where the fuse size required exceeds the max ampacity of the fuse.
This Power Distribution Panel houses both AC breakers for 120V circuits as well as Blade Fuses as shown above for all of the 12V DC devices in your camper (lights, fans, usb outlets, etc).
What would you charge me to design my wiring system? If I provide the requirements and components.
I am currently not offering custom wiring diagrams. Sorry about that! But, from the wiring diagram request form you filled out, this diagram should get you 80% of the way to what you are trying to accomplish it seems: https://www.explorist.life/30a-camper-inverter-with-solar-and-alternator-charging-wiring-diagram/
This is why I try to stay away from anything Chinese, not just fuses but inverters, charge controllers and batteries!
Obviously you can do whatever you like, but avoiding products for a specific country of manufacturer is not a good metric for determining if a product is good or poor quality. For example, which of the following would be a more quality item?
A product that is designed in the USA; carries a UL listing, but manufactured in China.
or…
A product that does not carry any kind of UL listing or certifications but is made in Indonesia.
The product with the UL listing that is manufactured in China will likely be a higher quality product.
But if the only metric of finding high quality products was ‘avoiding chinese products’ would say that the non-UL listed product would be higher quality simply because it was not made in China.
Love your content and easy instructions.. question. If I’m running a DC appliance to my WFCO WF-8930 distribution panel, do I need to bring the negative wire from my DC appliance back to my distribution panel, can I just ground the negative wire to metal (sheet metal) somewhere close to save on copper wire? assuming the Lithium batts are already chassis grounded and assuming I sand off any paint so that I have a good ground?
Ideally, yes. You should bring the negative wire back to the fuse block. This is the proper way to do it.