Fuse Identification

SwiftRaven · 03-18-2021, 06:30 PM

I am hoping someone can identify the fuse that is between the battery bank and the inverter. It is a Blue Sea Systems fuse but lacks another I.D. I tried to pull the cover but it will not budge.

Scalf77 · 03-18-2021, 07:09 PM

It is a Class T fuse, they are generally large current rated. I suspect you have an inverter. The cover is a little tricky but will come off.

-greg

BrianW · 03-19-2021, 11:52 PM

My fuse cover looks a little different, but it slides off. Give that a try if you haven’t already.

Kibo · 03-20-2021, 10:58 AM

Try squeezing in the middle near the base and lifting:

SwiftRaven · 03-20-2021, 07:19 PM

Thanks to all. If or when the fuse needs replacing what tools do you use? Nut driver and fuse puller. There is a lot of juice flowing through and those studs are close enough to be a hazard!

Scalf77 · 03-20-2021, 08:00 PM

Just a nut driver, and then you can remove it. If you can disconnect battery before great, at a minimal you would like to make sure there are not any high current devices running at the time you pull it. You wouldn't remove it while running the inverter or charger.

Chances are you will never have to replace, they are generally sized large enough for the current asked of them. It is always good to check the tightness now and then, maximum torque is 190 in-lb. (21.47 Nm). I generally check all the major bus connection once a year. Another good thing to do is get one of those infrared thermometer guns, and measure the temperature with things off and start turning things on and measure any change. Keep that data for when you have a problem, and then you will have good data to compare to. Most connections that are loose will show a temperature increase.

-greg

SwiftRaven · 03-21-2021, 06:02 AM

Thanks again for the great suggestions. In the MagnaSine installation manual they specifically state that the only connection in the path between the battery bank and the inverter should be the fuse block. I would like to have a switch between the fuse block and the inverter (2000 watt). I have a switch rated at 275 amp continuous and 455 amp intermittent. Is this a bad idea?

Also, related to fuses, my 2015 Sprinter build does not have any fuses in the solar panel path. Zamp recommends 40A fuse at the panel and at the battery bank. Do other SMB owners observe the same with their rigs?

Scalf77 · 03-22-2021, 06:27 AM

From their perspective, they don't want their device running a high amp conversion and then have the battery disconnected. So the switch should in a position that it is not easy to use, at least not accidentally. Your switch would cover the maximum continuous load of the unit (267 amps), but you wouldn't have much room for other 12 volt loads. I also expect that the fuse is for 300 amps, so I wouldn't want a switch that was lower.

For the solar, I would fuse at the panel if possible,. or especially before the power wire go through the body. The general rule of thumb is to fuse close to the power source. That would also mean that the fuse from the controller should go closer to the controller than the battery.

Thinking of the last SMB I worked on I don't think there was any fusing on the output of the controller.

-greg