why would someone do this

[Cmdr_Suds]

409.21(B) allows the buss head to cover but ... our buss heads are high enough a lift is required. Therefore two men, harnesses, tie-offs, and 15+ minutes for a lift to arrive. That versus one man who can walk up to the panel. One fuse blown at the buss and we've paid for having fuses added to several panels. But you get to submit prints to us and we'll tell you up front it's what we want. Then we coordinate the buss.

Its one thing if they are coordinated but most of the time I see this situation, they are not. You and the people you work with may truly understand what you are doing and will coordinate the fuses, but I see far too often people who don't understand and will not listen to a lowly contractor. In the end, as long as it doesn't violate code and simply cost the customer more, who am I to tell them differently?

 

[pfalcon]

A few years ago I was at a plant to help startup a machine. I think the machine control panel had 200A fuses in the main. They fed it off 90 Amp fuses from an overhead bus.

:?

The electrician who wired it up made a point of telling me that, and was quite proud of himself for doing so. I think the real load was about 80A , but I don't like to be real close as you never know what someone will add to a panel down the road.

:rotflmao:

Its one thing if they are coordinated but most of the time I see this situation, they are not. You and the people you work with may truly understand what you are doing and will coordinate the fuses, but I see far too often people who don't understand and will not listen to a lowly contractor. In the end, as long as it doesn't violate code and simply cost the customer more, who am I to tell them differently?

I can't say it hasn't happened here. The old school used to bump up fuses every time they failed. And even though our facilities people miss the sizing on the buss from time to time - proximity seems to favor the panel fuses failing first. But hey, if the buss blows first they usually call me to complain. So then I get to laugh at them and ask: "And you thought that would work why?"