Greetings, new to the forum. I have a DIY Bridgeport conversion I built over 10 years ago with stepper motors controlled by mach 3. I'm currently upgrading it with servo motors, and and switching to a Centroid acorn controller Kit, building a new computer for the controller, and a complete new panel to house everything. I've done all of my homework as far as reading all the Centroid literature, watched all the videos enough to get a good jump on things. The only thing I'm confused at is that the new servos that I'm using are from China, and came as a kit (motor & driver) with not much literature. The specs says Power:1.8kw (1800 watts)*Voltage:220v single phase*Current:6A*Output current 30A*Rated Torque: 6Nm. I don't have a issue wiring everything up, but I'm stuck at what breaker size should I use, the specs didn't give a amp draw. If it's based on the 1.8kw then I know that a 15 amp breaker is good up to 1800 watts. Or do I size it for the 6A current. or the output current 30 amp which is self explanatory.
Thanks for the help cncshaker
Choosing the correct breaker size
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cncshaker100
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- Joined: Thu Mar 10, 2022 8:40 pm
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Gary Campbell
- Posts: 2179
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- CNC12: Yes
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- Location: Marquette, MI
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Re: Choosing the correct breaker size
1.8 kw / 230v = ~8A. Since it's a motor, I would use a 10 or 12 if you expect heavy use, which is unlikely with motors of that size when you are used to steppers
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rk9268vc
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- Acorn CNC Controller: Yes
- Allin1DC CNC Controller: No
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- CNC12: Yes
- CNC11: No
- CPU10 or CPU7: No
Re: Choosing the correct breaker size
If youre talking the breaker in your building's breaker box, get the biggest one for the gauge of wire you ran. (see fire code/ electrical code)
If you mean the breaker in your enclosure, you need to size it to the load.
Also important to note the different trip curves (type A, B, C, D, etc)
You will typically want at least 2 breakers in the enclosure, a type B for your electronics, and a slower trip curve one for the motors/ servos
For servos you want a type C, and for big motors with high inrush youll want a type D
the different trip curves is how tolerant they are to inrush before tripping. You want a separate one for your electronics that is more sensitive. You dont want to use your semiconductors as a fuse haha.
If you have more application questions, Automation Direct has phenomenal engineering tech support. give them a call and theyll help you find your breakers
If you mean the breaker in your enclosure, you need to size it to the load.
Also important to note the different trip curves (type A, B, C, D, etc)
You will typically want at least 2 breakers in the enclosure, a type B for your electronics, and a slower trip curve one for the motors/ servos
For servos you want a type C, and for big motors with high inrush youll want a type D
the different trip curves is how tolerant they are to inrush before tripping. You want a separate one for your electronics that is more sensitive. You dont want to use your semiconductors as a fuse haha.
If you have more application questions, Automation Direct has phenomenal engineering tech support. give them a call and theyll help you find your breakers