You're on the right track, but let's refine your calculations and code references for a more accurate and compliant installation

Your Calculations and Code References Review
FLC (Full Load Current)

430.248 is the correct table. 15 HP @ 240V, 3-Phase yields 42 Amps FLC.

Correct. Overload Protection

430.32 is the correct section. With a SF less than 1.15, you can protect at 125% of FLC. 42 Amps 1.25 = 52.5 Amps. You are using 60A Time Delay Fuses.

Correct Branch Circuit Conductors

430.22(E) --> @ 140%(FLC) = 58.8 amps = #6 copper.

Correct Feeder Conductors

430.22(E) --> @ 140%(FLC) = 58.8 amps = #6 copper.

Correct Feeder OCPD

430.52 --> 250%(FLC) = 105amps --> 100 amp inverse time ckt breaker (Don't believe next size up is allowable here)

CorrectKey Considerations and Potential Issues


Elevator Specifics (Crucial)

Elevators have unique starting and running characteristics. Always consult the elevator manufacturer's specifications for specific electrical requirements. They may specify conductor sizes, OCPD types, and even require dedicated circuits. Nameplate data is essential for accurate sizing.

Your calculations should be considered preliminary until you have the actual nameplate data.2. Duty Cycle/Intermittent Operation

Elevators operate intermittently. While you correctly applied 430.22(E) (140% for intermittent duty), verify that your application truly falls under "intermittent duty." The actual operating characteristics of the elevator will determine if this is sufficient. More frequent or longer runs may require larger conductors.
3.

Voltage Drop

Voltage drop calculations are critical for elevator installations. Excessive voltage drop can cause the motor to run inefficiently, overheat, and potentially damage equipment. Calculate voltage drop from the panel to the motor, taking into account the anticipated load and distance. #6 copper might be insufficient for long runs, even though it meets the minimum ampacity requirement. Use a voltage drop calculator to verify.4.

Disconnect Sizing

Your calculations focus primarily on the motor branch circuit. The disconnect itself must be rated to interrupt the full load current of the motor. The disconnect needs to be HP-rated for the 15 HP motor at the applicable voltage.5.

Grounding/Bonding

Ensure proper grounding and bonding according to Article 250. Pay particular attention to bonding of metal raceways, enclosures, and the elevator car.
6.

Elevator-Specific Requirements (Article 620)

Article 620 of the NEC covers specific requirements for elevators, dumbwaiters, escalators, moving walks, platform lifts, and stairway chairlifts.

You MUST consult Article 620. Some key sections: 620.11

Supply Conductors. Addresses conductor sizing and types.

620.13

Voltage Limitations.

620.51

Disconnecting Means. Discusses the location and requirements for the elevator disconnect.

620.61

Overcurrent Protection.

620.85

Grounding

Summary and Recommendations


Get the Nameplate Data

Obtain the motor nameplate information (HP, voltage, FLA, service factor, etc.) immediately.2.

Consult Elevator Manufacturer

Review the elevator manufacturer's installation instructions and electrical specifications.3.

Article 620

Thoroughly review Article 620 of the NEC.4.

Voltage Drop

Perform voltage drop calculations.5.

Disconnect Rating

Ensure the disconnect switch is HP-rated for the motor.6.

Grounding

Ensure proper grounding and bonding.

Example Adjustments Based on More Information

Let's say the elevator manufacturer's specifications state that the motor runs frequently and recommends a minimum conductor size of #4 THHN copper. Even if your initial calculations indicated #6 THHN was acceptable, you must follow the manufacturer's specifications.

Disclaimer: I am an AI chatbot and cannot provide electrical design services. This information is for educational purposes only and does not substitute professional electrical engineering advice. Always consult with a qualified and licensed electrician for electrical installations.* Flag for review