Panel mounted hinge style fuse block holders

[testsubject]

I am having a discussion with an engineer and I say that the fuse should be mounted in a panel with the hinge on the bottom and he states that it does not matter since the fuse holders have a detent that holds it in place so the hinge can go on top.

I feel that I am right but cannot find any supporting documentation. UL508 has nothing that I could find.

If any of you have a document that describes how the fuse block should be mounted I would appreciate it.

 

[LadderLogic]

Let's see. So if the fuseholder is mounted with the hinge side up, someone flips the fuse upwards to disconnect the circuit, then accidentally hits it with his hand - not too hard but just enough to overcome the detent, the fuseholder flips down... boom.

Gravity always works. Detents - well, most of the time.

 

[testsubject]

That is what I say, but his arguement is that the detent is strong enough and there is no official document stating otherwise.

I need to find a code standard that I can point to stating how to install these type of fuseblocks.

 

[Ken Roach]

Conventional wiring also puts the "hot" side on top, so if the fuseholder hinge was on top and the holder was partially open, the fuse end could be exposed and "hot". And when you put in a new fuse, you could potentially touch the hot contact.

Of course, we all wear our 600V gloves and use fiberglass fuse insertion tools every time, right ?

I realize you're asking for a citation from a codebook, which I don't have offhand. Over at MikeHolt.com there might be folks more familiar with the NEC and UL508 who could help.

 

[leitmotif]

In NEC it states switches shall be mounted such that the "down position" is off. As it was said previous this is a gravity consideration and gravity seems to work quite well most if not all time.

Maybe there is nothing stating specifics to fuse but seems like a precedent for good design to me.

I agree with Ken Roach also.

Dan Bentler

 

[testsubject]

The fuse holder terminal we use pulls the fuse completely out of the holder when open so there is no "hot" issue although we also bring the power in from the bottom. (the power cords come in from the bottom of the enclosure) For us, power flows from the bottom up.

Thanks Ken!

 

[testsubject]

Another thing about these fuse block terminals; the jumpers between blocks are inserted on the hinge side.