can I use this wire?

[Madsalts]

Hi,

I'm wiring up two motors for an automatic fish feeder for an aquarium. Given the nature of the project, the device will frequently see use while not attended. Therefore, it is vitally important that it not catch fire. The motor that draws more current has a stall current of 800 mA, with a 400 mA fuse installed. Both motors are 12V. I purchased (from Ebay) wire to use for the project. It's made by NTE, was sold as copper, but it is not (probably aluminum), is rated: 22 GA, 300VH, and is solid. This wire is very brittle. I am trying to wire something and then bend the wires to get the motors into a housing. The wire has broken twice while trying to do this. The second time, just now, I was hardly doing anything to the wire.

I have some wire that I'd like to use in place of this junk, and want to know if you think it would be safe. It's copper speaker wire made by radio shack. It's 24GA with clear insulation. It specifically states "NO IN WALL" on label. So, can I use this?

 

[KJ6EAD]

Yes, at least it's stranded copper so it'll have some flexibility, but it's far from ideal. Although the gauge is easily capable of the current, often in cases like this where mechanical strength is paramount, it's best to use the largest wire than can reasonably fit the connections and keep the strand count at 19 or more.

 

[Tha fios agaibh]

I'd be concerned about the ambient temperature inside the housing.
You might want to use a thermal fuse at the motor end as well as your 400ma fuse at the source end.

 

[Madsalts]

The motor will only run for, at most, 5 min every hour. More realistically, it will run for 20 sec./Hr. You don't still think that I'd need a thermal fuse, do you?

 

[Tha fios agaibh]

Your probably right, But not a bad idea imo.
Your fuse will protect the motor, but their could be another failure like a transformer. At 400ma I don't see much concern.

 

[Colin Mitchell]

400mA is far to small for a motor. It will fail prematurely.