what fuse to use?

[Finale]

I want to mod and add a fuse holder to my chinese projector. Like this ones:



They are panel mount fuse holders that the fuse is put inside.
How do I determine what fuse to put inside though?
I measured with a multimeter that my projector draws 330 Watts when displaying the ilda test pattern with all the modules at max output in a high ambient temperature. Do I get my number like this, then use the next max rated fuse like 500W or is there a different correct way for figuring this out?

[Finale]

Just saying I havent found an answer to this myself yet. If anyone reading this knows I still would like an answer. thank you.

[lasersbee]

Have no idea where you are from.
At what mains voltage is your Projector running on ??

Fuses are rated in Amperes not Watts.

At 330 Watts on 120VAc your projector draws ~2.750 Amps.
At 330 Watts on 240VAC your projector draws ~1.375 Amps.

I would suggest to use a fuse ~1 amp over this if your projector
does not have a high inrush current when first turned on. If it
does then choose a slightly higher fuse rating.


Jerry

[JohnYayas]

Fuses are typically picked to protect the wiring from melting in case of a short. Wire size is picked to support the amount of current your devices uses. If you just want a fuse that is a little more than what your projector consumes then you can do that but that isn't really how it is supposed to be done. So, just figure out what your wire sizes are and how much your projector consumes and make sure you pick a fuse that is greater than what the projector consumes but less than what your wiring can handle.

[Draco]

I generally use about a 1 amp higher then an expected load as well, fuse sizes are not based on internal wire sizes but are picked as an over current device to prevent damage in an over current and in severe cases to prevent a fire, wiring is not the only consideration, I have never heard of any one selecting a fuse based on the wire gauge in side a unit, it's based on the current draw and there are a lot of items that could cause a fire then just wire, a shorted driver transistor could cause all kinds of damage to it's pre-driver or to it's load, I have seen them even melt and catch other parts on fire or destroy a PCB board and had all the wiring just fine,
From an electrician's view in a house's wiring system a fuse or breaker would be set for the safe current capacity of that homes cabling to the power outlets, but inside an electronic device there is a lot more importance on protecting the electronics inside the device from a fire or further damage to other stages in the said device.
You also have fast acting and delayed acting, a delayed acting may be used on the power supply that takes in a surge to charge it's internal components like capacitors that for a very short time take in a lot of power to charge then but with a short duration, a slow blow fuse would then be used.
Another factor of course is voltage, a fuse rated for 120 volts but used on 240 may still arc over inside the fuse and not correctly operate as it was intended.
There was one tv shop in my area that covered a blown fuse with aluminum foil, the internal damage from doing that led to a dangerous or a catastrophic failure, I usually would decline repairs when I saw that shops sticker and found foil on critical fuses, we called them ASA2millon as a joke as some fuses would have the Text ASA then the current rating and voltage, so ASA 2AMP 250 volts.

[lasersbee]

Exactly.....
The point of a fuse...

Jerry

[Finale]

I would suggest to use a fuse ~1 amp over this if your projector
does not have a high inrush current when first turned on. If it
does then choose a slightly higher fuse rating.

This is all I needed to know, thanks.