I have a spec for a printing press. It says that the current ( normal running) is 50A. It is requiring the press to be fused at 63A (I am assuming for start up). My question is, if I fused it for 63A, which would have to be fused at 70 or 80A, would I just rely on the thermal protection for the motor or motors because 70 or 80A fusing is a vast difference from 50A I was thinking of fusing it at 60A swith a soft start, maybe. Thanks in advance.
Overcurrent Proctection for printing press
- Thread starter Benton
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- San Francisco Bay Area, CA, USA
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- Electrical Engineer
Not enough information, but there are some clues to point to potential pitfalls.
63A is NOT a standard fuse size in North America, but it IS a standard fuse size in Europe. So that right there tells me this is probably a European press, most likely German. That being the case, you will need to know a LOT more about how it is designed before connecting it. If for example it has AC motors inside, they will likely be 50Hz designed motors and if you connect them here to 60Hz, those motors will run 20% faster whcih can throw off the timing with other equipment in the press, especially if the other equipment is DC powered. If on the other had it has all DC motors, as many presses do, then you will have DC drives inside, which may need special fuses to protect them.
Those are just two of many issues I'd be concerned about. I think you (or someone) needs to take a good hard look at the press and determine all of the necessary information before making decisions on powering and protecting it.
63A is NOT a standard fuse size in North America, but it IS a standard fuse size in Europe. So that right there tells me this is probably a European press, most likely German. That being the case, you will need to know a LOT more about how it is designed before connecting it. If for example it has AC motors inside, they will likely be 50Hz designed motors and if you connect them here to 60Hz, those motors will run 20% faster whcih can throw off the timing with other equipment in the press, especially if the other equipment is DC powered. If on the other had it has all DC motors, as many presses do, then you will have DC drives inside, which may need special fuses to protect them.
Those are just two of many issues I'd be concerned about. I think you (or someone) needs to take a good hard look at the press and determine all of the necessary information before making decisions on powering and protecting it.
Last edited:
chris kennedy
Senior Member
- Location
- Miami Fla.
- Occupation
- 60 yr old tool twisting electrician
Could very well be 400V also.
If you get Jr's questions answered and still want the printer here are some 63 amp fuses http://www1.cooperbussmann.com/pdf/288cac0e-46c9-4fea-9477-30b41a9b7620.pdf
Thanks guys. You guys are intuitive and smart. The press is German and the voltage is 400. I found that the voltage is stepped up to 400 inside of the machine. I will have to get a couple of buck boost to go from 208V to 230V. I will have to look into those fuses because the company I work for is going to buy the press.
broadgage
Senior Member
- Location
- London, England
Are you certain that the voltage is stepped up to 400 internally ?
That would be rather uncommon.
I would suspect that it is intended for a standard European supply, 3 phase, 4 wire, with 230 volts between phase and neutral and 400 volts between phases.
If so it Probably wont work work from a USA type 3 phase 120/208 volt system, even if this be increased to 230 volts via transformers.
That would be rather uncommon.
I would suspect that it is intended for a standard European supply, 3 phase, 4 wire, with 230 volts between phase and neutral and 400 volts between phases.
If so it Probably wont work work from a USA type 3 phase 120/208 volt system, even if this be increased to 230 volts via transformers.
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