In-line fuses

[Hokkey]

Hey guys,
I'm working on wiring my control panel and I had a question about fuses.  I'm splitting a 12v line from my pc's power supply to wire up some spectralite buttons into an LED Wiz.  It was recommended to use an in-line fuse to protect the system.  This is where I'm lost.  I'm trying to figure out which product I need and which size.  I'll have 30 LEDs wired into the system, all 12v.  I was told they run at 20mA. 
I'm hoping someone has some electrical experience to help me out. 
I've seen a few different types of fuses (fast blow, slow blow, AGC, ATM, ceramic, glass) and I just have no clue on which is best.  I've searched around and I see equations for putting fuses into houses that run on 120v or 240v, but that doesn't seem to work for my project. 
I really appreciate any help out there. 

Thanks,
~Hokkey

[PL1]

Hey guys,
I'm working on wiring my control panel and I had a question about fuses.  I'm splitting a 12v line from my pc's power supply to wire up some spectralite buttons into an LED Wiz.  It was recommended to use an in-line fuse to protect the system.  This is where I'm lost.  I'm trying to figure out which product I need and which size.  I'll have 30 LEDs wired into the system, all 12v.  I was told they run at 20mA. 
I'm hoping someone has some electrical experience to help me out. 
I've seen a few different types of fuses (fast blow, slow blow, AGC, ATM, ceramic, glass) and I just have no clue on which is best.

Here are four basic considerations when selecting a fuse:

1. Voltage
Must be rated equal to or higher than the voltage on the line.

It's OK to use a 250VAC fuse on a 120VAC line, but not OK to use a 125VAC fuse on a 240VAC line.

The VAC and VDC ratings will be different.

Fuses rated for 32VDC will work for your setup.

2. Amperage
30 LEDs * 20mA = 600mA

A 1A fuse gives you wiggle room while still providing protection in case of a short.

3. Blow speed
A normal blow speed should work fine for this application.

Since you are using an LED controller, having all of the LEDs switching on and off might cause momentary power spikes that could trigger a fast blow fuse. (2nd choice if you can't find a normal blow)

You don't need a slow blow since LEDs don't have a large inrush current like a CRT when they first power up.

4. Physical size/form
The fuse needs to properly fit in the holder.


Scott

[Hokkey]

Scott, you're awesome. 
This really helps me out.  Thanks!