Two pole (?) disco with only 1 single fuse slot in the middle?

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photonboy

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I have never seen one of these before. I can't really see how the internals connect, this is being represented as a 60A 2p.

Question is are both lines being fused here?

Thanks.
 

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photonboy said:
I have never seen one of these before. I can't really see how the internals connect, this is being represented as a 60A 2p.

Question is are both lines being fused here?

Thanks.
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That's a single pole switch.
 
Looks to me that the black wire feeds the bottom of the fuse. That's a setup I've never seen for sure.
 
Looks like it might be a three pole disconnect where someone removed two of the fuse clips and replaced them with lugs.
 
I've installed something similar as a single pole DC disconnect on a functionally grounded system in the past. But what we're looking at makes no sense as a 2-pole AC disconnect to match the accompanying drawing.

On some switches you get to raise the voltage rating from 300V to 600V if you use the poles in series. A bit odd with a fuse in the middle though. I question if that's legit without seeing the label.
 
It looks like someone removed the other terminals and then wired the switches in series, possibly to increase the voltage rating.
 
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LarryFine said:
I don't see the jumpers you see.
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I can't make out what is behind the clear plastic. Appears to me to be a jumper. If it isn't a jumper, nothing happens when the device is toggled so that's why I was assuming. I can't tell if what I'm seeing is mounted to the teminals or if that is something in the back mounted to the can.

Screenshot 2025-04-10 073259.jpg
 
4x4dually said:
I can't make out what is behind the clear plastic. Appears to me to be a jumper. If it isn't a jumper, nothing happens when the device is toggled so that's why I was assuming. I can't tell if what I'm seeing is mounted to the teminals or if that is something in the back mounted to the can.

View attachment 2576685
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I couldn't tell either but was a little suspicious that it may be something similar as suggested and all three poles along with the fuse are all in series somehow. Why makes little sense other than maybe for higher voltage and/or DC applications. Though the switch still isn't listed for any more than it is marked.

I also kind of suspect field modification?

I've seen two pole units factory built on three pole frame and just left parts out of typically the center pole. Those usually not stocked and is cheaper to just purchase a three pole unit from stock and not use one pole if you only need two pole unit. Particularly for 600 volt rated switches.
 
There are some items that are listed for certain configurations but not specifically marked. For example, Square D QO single phase main lug load centers are capable of being used at 48 and 125 VDC, as are the two pole QO breakers 70 amps or less, but you will not find it written anywhere on the package.

I have seen some disconnect switch instructions that tell you to put poles in series for DC operation.
 
Yes, it looks like the circuit is routed through the blades multiple times to increase voltage rating. Single pole, not two poles, and 30A fuse, not 60A. Clearly not what the print shows.
 
LarryFine said:
Actually, multiple poles in series can increase current-interrupting capability and contact life,
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It used to be done as a matter of course in using primarily AC rated discos to interrupt high voltage high current DC circuits because of DC's propensity to support an arc.
 
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