Fuse size and locations

Okay guys my system only includes a Micro 810 timer rated at .125a,a solenoid valve for oil rated at .4a and a small limit switch which I assume is very little amperage.

So I am tapping in the machines current 208VAC-120VAC transformer that from the looks of it is there for accessories not being used because the primary has 208V going to it but the secondary 120VAC side just goes to a terminal block with nothing connected and I assume the primary side is already fused.

So I need to just fuse the positive side of my 120VAC-24VDC PSU rated at 1.3a,right?

Here it is
POWER SUPPLY SW 24VDC 1.3A 30W - S8VS-03024

Also here is the timer 2080-lc10-12-QBB
http://literature.rockwellautomation...g001_-en-p.pdf

My basic circuit will be the PSU going to terminal blocks where I will power my timer,valve,Cylinder Limit switch and 1 pushbutton. All inputs and output go to timer like a PLC.

So where do I need to fuse and what sizes,fast burn and can I just get away with one 1.5a din mount breaker on the PSU instead of all of this??

Looks to me like the din mount breaker would suffice, however I would like to install fuses to protect the outputs from a shorted out solenoid coil. I personally would use a fuse somewhere between .6 up to 1 amp between the output and the solenoid. McMAsters has a nice 24vdc din rail mounted fuseholder that is even lit when the fuse blows. Something I like to remember is that the fuse is actually designed to protect the wiring (at least that is my understanding).
Good luck with your project.

I would use a 1/2 amp AC breaker on the supply. 30 watts at 120 VAC is .25 Amps. A glass fast blow fuse (1 amp) on the solenoid if you want. Personally I would not fuse the output of the dc power supply this small. Just my opinion.

muusic_man said:

I would use a 1/2 amp AC breaker on the supply. 30 watts at 120 VAC is .25 Amps. A glass fast blow fuse (1 amp) on the solenoid if you want. Personally I would not fuse the output of the dc power supply this small. Just my opinion.

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What about the timer? I think of it as a PLC because it is programmable and solid state. It has all the electronic characteristics of a PLC. Would you fuse it and if so how do I fiind the fuse rating? And is this to protect the Timer,PSU or both in this case?

If you're really set on fusing the output of the power supply, put a 1 to 1.5 amp glass fast blow fuse on the +24 out of the PS and everything will be protected.