Datasets:

miadinside
/

motor-inrush-lra-generator-benchmark-2026

appliance_id stringlengths 13 24	equipment_name stringlengths 22 39	equipment_category stringclasses 7 values	nominal_hp float64 0.2 5	voltage_v int64 120 240	nema_code_letter stringclasses 5 values	kva_per_hp_range stringclasses 5 values	running_fla_amps float64 1.8 21.8	running_watts int64 216 5.23k	lra_starting_amps float64 9.5 118	inrush_multiplier float64 4.9 5.71	peak_starting_watts int64 1.14k 28.3k	inductive_surge_delta_watts int64 924 23.1k	soft_start_mitigated_lra_amps float64 4.5 37.8	soft_start_peak_watts int64 540 9.07k	min_recommended_generator_continuous_w int64 500 7.5k	min_recommended_generator_surge_w int64 1.2k 28.5k
ac_central_2_5_ton	2.5-Ton Central AC Compressor	HVAC	2.5	240	G	5.6-6.29	11.2	2,688	58	5.18	13,920	11,232	18.5	4,440	3,500	14,000
ac_central_3_0_ton	3.0-Ton Central AC Compressor	HVAC	3	240	G	5.6-6.29	13.4	3,216	71	5.3	17,040	13,824	22.7	5,448	4,500	17,500
ac_central_3_5_ton	3.5-Ton Central AC Compressor	HVAC	3.5	240	G	5.6-6.29	15.2	3,648	79	5.2	18,960	15,312	25.3	6,072	5,000	19,000
ac_central_4_0_ton	4.0-Ton Central AC Compressor	HVAC	4	240	H	6.3-7.09	17.9	4,296	96	5.36	23,040	18,744	30.7	7,368	6,000	23,500
ac_central_5_0_ton	5.0-Ton Central AC Compressor	HVAC	5	240	H	6.3-7.09	21.8	5,232	118	5.41	28,320	23,088	37.8	9,072	7,500	28,500
heat_pump_3_ton	3.0-Ton ccASHP Compressor	HVAC	3	240	H	6.3-7.09	14.1	3,384	77	5.46	18,480	15,096	24.6	5,904	4,500	18,500
heat_pump_4_ton	4.0-Ton ccASHP Compressor	HVAC	4	240	H	6.3-7.09	18.5	4,440	102	5.51	24,480	20,040	32.6	7,824	6,000	25,000
well_pump_0_5_hp	0.5 HP Deep Well Submersible Pump	Water_Pumping	0.5	240	J	7.1-7.99	4.9	1,176	28	5.71	6,720	5,544	11.2	2,688	2,000	7,000
well_pump_1_0_hp	1.0 HP Deep Well Submersible Pump	Water_Pumping	1	240	J	7.1-7.99	8.2	1,968	46	5.61	11,040	9,072	18.4	4,416	2,800	11,500
well_pump_1_5_hp	1.5 HP Deep Well Submersible Pump	Water_Pumping	1.5	240	J	7.1-7.99	11.5	2,760	64	5.57	15,360	12,600	25.6	6,144	3,800	15,500
sump_pump_0_33_hp	1/3 HP Submersible Sump Pump	Drainage	0.33	120	L	9.0-9.99	6.5	780	32	4.92	3,840	3,060	14	1,680	1,200	4,000
sump_pump_0_5_hp	1/2 HP Submersible Sump Pump	Drainage	0.5	120	L	9.0-9.99	9.8	1,176	48	4.9	5,760	4,584	20	2,400	1,800	6,000
air_compressor_2_hp	2.0 HP Workshop Air Compressor	Pneumatic	2	120	G	5.6-6.29	15	1,800	85	5.67	10,200	8,400	34	4,080	2,500	10,500
refrigerator_residential	25 cu ft Residential Refrigerator	Refrigeration	0.25	120	K	8.0-8.99	2.5	300	12.5	5	1,500	1,200	6	720	600	1,600
freezer_chest	15 cu ft Chest Freezer	Refrigeration	0.2	120	K	8.0-8.99	1.8	216	9.5	5.28	1,140	924	4.5	540	500	1,200
table_saw_1_75_hp	1.75 HP Contractor Table Saw	Machinery	1.75	120	H	6.3-7.09	14	1,680	75	5.36	9,000	7,320	30	3,600	2,400	9,500
furnace_blower_0_5_hp	1/2 HP ECM/PSC Furnace Blower	HVAC	0.5	120	J	7.1-7.99	7.2	864	36	5	4,320	3,456	15	1,800	1,200	4,500
pool_pump_1_5_hp	1.5 HP Single-Speed In-Ground Pool Pump	Recreation	1.5	240	H	6.3-7.09	9.5	2,280	54	5.68	12,960	10,680	21.6	5,184	3,200	13,500

Inductive Motor Locked Rotor Amperes (LRA) & Backup Generator Sizing Benchmark Matrix (2026)

1. Benchmark Overview & Physical Scope

During a power outage, emergency backup generators frequently stall and trip their circuit breakers when starting heavy motor loads (such as residential central air conditioners, heat pumps, and submersible well pumps), even when continuous running wattage is well within the generator's nameplate rating.

At the instant of startup (0 RPM), single-phase alternating-current induction motors produce zero counter-electromotive force (back-EMF). Inrush current is constrained only by the motor windings' low DC resistance and subtransient leakage reactance. Under NEMA MG-1 standards, this Locked Rotor Amperage (LRA) surge reaches 4.5x to 7.0x continuous full-load running amperes (FLA) across the initial 100 to 300 milliseconds.

This benchmark dataset provides harmonized empirical and analytical matrices tabulating running power (Watts), full-load running current (FLA), starting locked rotor current (LRA), peak volt-ampere inrush spikes, solid-state electronic soft-starter current mitigation (-65% to -70%), and minimum recommended generator surge/continuous capacities.

Interactive deterministic calculations and simulation workbenches are open-access and reproducible via the PowerLab Emergency Generator Size Calculator.

2. Data Schema & Feature Dictionary

Column Name	Type	Physical Unit	Description
`appliance_id`	`string`	—	Unique alphanumeric identifier for the motor equipment.
`equipment_name`	`string`	—	Full engineering descriptor and nominal capacity rating.
`equipment_category`	`string`	—	Operational domain (`HVAC`, `Water_Pumping`, `Drainage`, `Pneumatic`, `Machinery`, `Recreation`).
`nominal_hp`	`float`	`HP`	Mechanical horsepower equivalent.
`voltage_v`	`integer`	`Volts (AC)`	Nominal operating root-mean-square line voltage (120V or 240V split-phase, 60 Hz).
`nema_code_letter`	`string`	—	NEMA MG-1 locked-rotor starting code letter designation (Code Letters G through L).
`kva_per_hp_range`	`string`	`kVA/HP`	Standard locked-rotor kVA bracket per rated horsepower under NEMA MG-1 Section 10.37.
`running_fla_amps`	`float`	`Amperes (RMS)`	Rated steady-state continuous full-load running current.
`running_watts`	`integer`	`Watts`	Active real steady-state electrical power demand (P = V · I · cos φ).
`lra_starting_amps`	`float`	`Amperes (RMS)`	Peak locked-rotor inrush starting current.
`inrush_multiplier`	`float`	—	Starting current ratio (LRA / FLA).
`peak_starting_watts`	`integer`	`Volt-Amperes / Watts`	Instantaneous unmitigated starting surge volt-ampere demand.
`inductive_surge_delta_watts`	`integer`	`Watts`	Net starting surge step over steady-state running demand.
`soft_start_mitigated_lra_amps`	`float`	`Amperes (RMS)`	Starting current with closed-loop electronic soft starter installed.
`soft_start_peak_watts`	`integer`	`Watts`	Mitigated starting demand with soft starter.
`min_recommended_generator_continuous_w`	`integer`	`Watts`	Minimum recommended continuous alternator rating.
`min_recommended_generator_surge_w`	`integer`	`Watts`	Minimum recommended transient surge capacity to avoid subtransient voltage collapse.

3. Governing Engineering Standards & Physics Solvers

NEMA MG 1-2021: Motors and Generators (Section 10.37 Code Letters for Locked-Rotor kVA).
NFPA 70 / National Electrical Code (NEC 2023): Article 430 (Motors, Motor Circuits, and Controllers).
IEEE Std 399-1997: IEEE Recommended Practice for Industrial and Commercial Power Systems Analysis.
ISO 8528-5: Reciprocating internal combustion engine driven alternating current generating sets (Part 5: Generating sets transient performance).

4. Verification & Computational Reproducibility

All values in this matrix are derived from deterministic TypeScript physics engines executing closed-loop electrical equations without database dependencies or heuristic approximation.

Explore the open-source calculation implementation and API contracts at PowerLab Developer Documentation.

5. Formal BibTeX Citation

@dataset{powerlab_2026_motor_inrush_benchmark,
  author    = {{PowerLab Open Energy Research Group}},
  title     = {Inductive Motor Locked Rotor Amperes (LRA) and Backup Generator Sizing Benchmark Matrix},
  year      = {2026},
  publisher = {Hugging Face},
  doi       = {10.57967/hf/10419},
  url       = {https://www.powelab.org/home-energy/generator-size-calculator}
}

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