The Milltronics cnc mill needs a power modification. The old X axis DC motor used 120 volt single phase from a transformer in the mill. The new AC servo motor needs 208V 3 phase. Subsequently, I will need to supply the same power to the Y and Z axes when I replace those motors.
Are fuses necessary here since we’re staying inside the equipment box? I don’t think so, but there not a bad idea since we will be using lighter gauge wire then the 30 amp fuse would request. Not to mention, if a servo drive fails catastrophically. Better it blow up at 7 amps then at 30 amps. 😁 But these fuse block holders made by Phoenix Contact offer another benefit. You can bond them together. Meaning one wire can supply power to multiple fuses. It turns a fuse block into a distribution block.
And yet, I still ran jumper wires. But hay, not as many. 😁 The block can handle 10 amps. So how many can a block of fuse holders handle with one feed? I couldn’t find that answer, but I am guessing 10 amps. Though, considering the block could handle 8 gauge wires, plus two 14 gauge wires without an issue…. well, I have to wonder.
But where shall such a contraption be placed in such a confined cabinet! Well, removing the old X axis driver card opened up a nice location. It’s not perfect, but it’s a work in progress. I will be replacing a lot of the crap in this compartment because, well, it’s me. It’s what I do. 😎 So this location may change. Then again, it may not. I’m dodgy like that. 😂🤣
But why so many fuses? Well, It’s 3 phase, so we need to fuse each leg, which comes out to 3 blocks. These blocks separated by some grounding terminals. Each block contains 6 fuses. I need 4 fuses for axes, I need one single phase for fans, and one, ok fine. I got a bunch of these fuse blocks cheap on eBay and I fit as many as I could . I would have gone to 7 if I could. 😅