Actuator Stall Current and Fuse Sizing Calculator

Estimate a preliminary fuse-current target from actuator run current, stall current, service factor, and allowable stall-current fraction. The result is a preliminary engineering estimate, not a product rating or safety approval.

Calculate the documented engineering estimate

Enter the measured or assumed inputs in one unit system. The calculator converts to SI internally, evaluates the stated model, and displays the result in the selected unit system.

Continuous-current fuse target --

Stall-current allowance target --

Preliminary fuse-current estimate --

Enter values inside the documented model domain.

Engineering visualizer

Schematic, not to scale. The drawing updates from the production calculation engine and labels the main outputs.

Calculator by FIRGELLI Automations.

Embed this calculator

When embedded on another page, the calculator shows only the working tool. FIRGELLI attribution, the visualizer, and the calculation-error report remain available.

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What This Calculator Calculates

What does actuator stall current and fuse sizing mean? This quantity describes one specific part of the actuator design problem. It should be read as a model output, not as a complete product selection rule.

How To Interpret The Results

How should I interpret the actuator stall current and fuse sizing result? A larger result means the checked effect is becoming more important and should be compared with product data, mounting limits, or the next design check. A smaller result does not prove the whole system is safe.

When Not To Use This Calculator

When should I not use the actuator stall current and fuse sizing model? Do not use this model when the inputs are unknown, the mechanism is outside the stated boundary, or the decision depends on manufacturer ratings, fatigue, shock, compliance, or regulated safety approval.

Engineering model and calculation details

Estimate a preliminary fuse-current target from actuator run current, stall current, service factor, and allowable stall-current fraction.

The page separates the calculator result from product selection. It explains the inputs, limitations, interpretation, and next design checks so the result is not mistaken for a complete actuator rating.

Governing equations

Quantity	Equation	Model meaning
Continuous-current fuse target	`I_cont = I_run M`	Calculates continuous-current fuse target for the stated simplified model.
Stall-current allowance target	`I_stall_allow = I_stall f`	Calculates stall-current allowance target for the stated simplified model.
Preliminary fuse-current estimate	`I_fuse = max(I_cont, I_stall_allow)`	Calculates preliminary fuse-current estimate for the stated simplified model.

Variables and canonical units

Symbol	Variable	SI unit	Domain
`run_current`	Normal run current	A	finite engineering value in the documented model domain
`stall_current`	Measured or published stall current	A	finite engineering value in the documented model domain
`service_factor`	Continuous-current service factor	1	finite engineering value in the documented model domain
`stall_fraction`	Allowed stall-current fraction	1	finite engineering value in the documented model domain
`continuous_fuse_current`	Continuous-current fuse target	A	finite result from valid inputs
`stall_allowance_current`	Stall-current allowance target	A	finite result from valid inputs
`recommended_fuse_current`	Preliminary fuse-current estimate	A	finite result from valid inputs

Assumptions and boundary conditions

Inputs represent one consistent operating condition.
The model uses the simplified boundary stated on the page.
The model begins and ends at the user-defined actuator or mechanism boundary.

Limitations and omitted checks

The result depends on user-entered values and simplified boundary conditions.
The model does not replace FIRGELLI product data, installation review, endurance testing, or a qualified engineering review.
Shock, fatigue, misalignment, mounting strength, and controller behavior may govern before the calculated value.

Worked example using the default inputs

The default inputs show the substitution path and provide a known-answer check for the displayed outputs.

Stage	Substitution or result
Continuous-current fuse target	`I_cont = I_run M`
Stall-current allowance target	`I_stall_allow = I_stall f`
Preliminary fuse-current estimate	`I_fuse = max(I_cont, I_stall_allow)`

Interpretation: Use the result to decide whether the design needs a deeper product, mounting, electrical, thermal, or motion-control check.

What this model evaluates

Mode or effect	Status	Disclosure
calculated quantity	evaluated	The named output is evaluated for the stated model.
manufacturer rating	not evaluated	The result is not a manufacturer product rating.
installation detail	not evaluated	Mounting, alignment, shock, fatigue, and environment require separate review.

Common mistakes

Treating a simplified estimate as a manufacturer rating.
Mixing units or entering values measured at a different operating point.
Ignoring mounting, alignment, shock, duty cycle, or controller limitations.
Failing to compare the result with the next logical FIRGELLI design check.

Engineering references

OpenStax. University Physics Volume 2 - Direct-Current Circuits. Rice University, 2016. Supports: Ohm-law and DC circuit relationships used for voltage drop and power loss.. Accessed 2026-07-28. Source.
National Institute of Standards and Technology. Ampere and Electrical Measurement Context. National Institute of Standards and Technology, Accessed 2026. Supports: Electrical unit consistency for current, voltage, resistance, and power relationships.. Accessed 2026-07-28. Source.
National Institute of Standards and Technology. NIST Guide to the SI. National Institute of Standards and Technology, Accessed 2026. Supports: SI unit definitions and unit-consistent engineering calculation display.. Accessed 2026-07-28. Source.

Author, validation, and review status

Author: Robbie Dickson

Author profile: Robbie Dickson prepares FIRGELLI actuator education and calculator content for product users and engineering teams.

Engineering model type: DC actuator fuse-current screening model

Validation: The production JavaScript engine is compared with a separately written Python oracle across known-answer, SI/imperial-equivalent, boundary, invalid-input, and randomized cases.

Questions about this calculator or found an error? Message our engineering team.

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Actuator Stall Current and Fuse Sizing Calculator