Depending upon what type of "unit", you would want at least an 85-amp breaker, and the next standard size would be 90 amps. You might use an 80, depending upon the duty cycle of the unit, but the 90 will be required for constant use.
A #10 wire has the capacity for 30 amps. No breaker larger than 30 amps should be used to protect the circuit.
3000 / 240 = Amps. You de-rate a breaker by 20 % for continuous load like an oven. You could get by with a 20 Amp breaker and 12 AWG wire. However, I would recommend 30 Amps and 10 AWG for an oven for the long run.
For typical residential house wiring 12 AWG wire is required for a 20 Amp breaker. If you change out the breaker for a 25 A breaker you would have to rewire the circuit with 10 AWG. In that case you could up the breaker to 30 Amps. All outlets and switches should be rated at the same voltage and current as the breaker.
LRA (locked rotor amps) is not used to calculate the breaker size. Breaker's are used to protect the size of the conductor that is connected to it. Motor calculations are based on the motor's FLA (full load amps).Conductor size is 125% of the motor's FLA.Breaker size is 250% of the motor's FLA.This is the only occasion when the breaker is sized larger that the conductors maximum amperage rating. This is due to the motor drawing up to 300 to 600% of its FLA when starting.If you state the motor's wattage, voltage or amperage this calculation can be calculated here.
The electrical current requirements of a wall oven can vary, depending on the heating elements used by the manufacturer. To determine the current use, refer to either the operators manual, or the service tag. The service tag may list the power consumption in Watts, in which case you'll need to convert the watts to amps using the following formula: Amps = Watts/Volts Once you've determined the current draw in Amps, OVER-rate the breaker by 20%. For example, if you calculate that the oven draws exactly 20 amps, over-rate that to 24 amps, then use the next larger size breaker and wire that is appropriate to the breaker; typically that would mean a 10 AWG wire and 30 Amp breaker. BUT!!! If you have any questions, contact a licensed electrical professional.
To determine the correct size breaker, you need to ensure that it is rated higher than the running amps of the unit. For a unit drawing 58 running amps, a breaker that is rated for at least 70 amps would be appropriate to provide a safety margin and prevent tripping due to overload.
A #10 wire has the capacity for 30 amps. No breaker larger than 30 amps should be used to protect the circuit.
The appropriate breaker size for a washer is typically 15-20 amps.
The recommended breaker size for a hot tub is typically 50 amps.
3000 / 240 = Amps. You de-rate a breaker by 20 % for continuous load like an oven. You could get by with a 20 Amp breaker and 12 AWG wire. However, I would recommend 30 Amps and 10 AWG for an oven for the long run.
Add up your amps to calculate your breaker size. Add up your loads (amps), divide by 0.8, and choose that size breaker. If that number does not correspond to a standard size breaker you go to the next higher standard size breaker.
For a circuit with a load of 10 amps, a breaker of 15 amps should be used for adequate protection. It is important to choose a breaker size that is slightly higher than the load to prevent frequent tripping and ensure safety.
For typical residential house wiring 12 AWG wire is required for a 20 Amp breaker. If you change out the breaker for a 25 A breaker you would have to rewire the circuit with 10 AWG. In that case you could up the breaker to 30 Amps. All outlets and switches should be rated at the same voltage and current as the breaker.
For a 41 amp load, you would typically use a 50 amp circuit breaker. The general rule is to select a breaker size that is 125% of the continuous load amps or equal to the load amps if it is not a continuous load. In this case, 41 amps is considered a continuous load, so you would round up to the nearest available breaker size, which is 50 amps.
LRA (locked rotor amps) is not used to calculate the breaker size. Breaker's are used to protect the size of the conductor that is connected to it. Motor calculations are based on the motor's FLA (full load amps).Conductor size is 125% of the motor's FLA.Breaker size is 250% of the motor's FLA.This is the only occasion when the breaker is sized larger that the conductors maximum amperage rating. This is due to the motor drawing up to 300 to 600% of its FLA when starting.If you state the motor's wattage, voltage or amperage this calculation can be calculated here.
The recommended range breaker size for a circuit breaker in a residential electrical panel is typically between 15 to 20 amps.
The electrical code states that a 7.5 HP 460 volt three phase motor draws 11 amps. For fuse sizes, non time delay - 30 amps, time delay type D - 20 amps and if using a breaker it will be 30 amps. Minimum wire size is #12 and the maximum setting of overload devices will be 13.75 amps