Motor Protection Worksheet Chart

Use this worksheet after the calculator result to document FLC source, overload setting, short-circuit and ground-fault screen, conductor ampacity, disconnect rating, controller rating, and listed combination notes.

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Quick reference table

A motor protection worksheet is a calculator-led planning screen, not a final protection design. Record the calculator result, then verify the adopted NEC path, motor nameplate, overload device, short-circuit device, listed combination equipment, manufacturer instructions, utility requirements when present, and AHJ requirements.

Motor protection worksheet checkpoints

Motor protection worksheet checkpoints
Checkpoint	Record from calculator	Verification before use
FLC basis	Full-load current source	Confirm nameplate and applicable adopted NEC path
Overload	Overload protection value	Confirm nameplate service factor and overload relay data
SC/GF screen	Short-circuit and ground-fault value	Confirm protection type, device class, and equipment ratings
Conductors	Conductor ampacity result	Compare with motor branch-circuit conductor requirements
Controller package	Disconnect, starter, contactor, and SCCR notes	Confirm listing and manufacturer instructions

Separate motor protection items

Separate motor protection items
Item	Typical record field	Why it stays separate
Overload protection	Overload relay or drive overload setting	Protects the motor from running overload, not branch short-circuit current
Branch SC/GF protection	Fuse, breaker, type, and preliminary ampere screen	Protects branch-circuit conductors and equipment from short-circuit and ground-fault events
Disconnecting means	Disconnect rating and enclosure notes	May not match overload or branch-device size
Controller and contactor	NEMA size, coil voltage, HP rating, and duty	Starter selection depends on motor duty and listed equipment data
Listed combination	Device and controller combination reference	Can control SCCR, allowed devices, and manufacturer installation rules

Formula basis

Protection review path = FLC source + overload screen + short-circuit and ground-fault screen + conductor, disconnect, controller, and listing checks.

FLC source identifies whether table current, nameplate current, or another documented basis was used.
Overload screen records the calculator overload value before nameplate, service-factor, and device checks.
Short-circuit and ground-fault screen records the preliminary protective device result and selected protection type.
Equipment checks include conductor ampacity, disconnect rating, controller rating, SCCR, and listed combination data.

Worked examples

Pump starter protection packetA field worksheet can keep table FLC, overload setting, fuse or breaker screen, starter size, disconnect rating, and listed combination notes together before equipment is ordered.

VFD-fed motor branchA drive installation should record motor nameplate current, drive overload setup, bypass condition, available fault current, and manufacturer branch-device instructions rather than using one calculator value for every device.

Assumptions. Balanced load and line-to-line voltage assumptions behind this chart.

The worksheet does not reproduce NEC motor tables and does not replace a listed combination, drive manual, overload relay manual, or manufacturer protection guide.
Special motors, VFDs, multi-speed equipment, duty-cycle limits, available fault current, and local amendments can change the protection path.
Utility service rules, equipment listing conditions, and AHJ interpretation can affect the final protection package.

Code and standard notes. Planning limits that should be checked before final equipment selection.

Verify the adopted NEC edition, motor nameplate, listed combination equipment, manufacturer instructions, available fault current, utility requirements when applicable, and AHJ requirements before motor protection decisions.
Use this worksheet as an educational planning record; overload protection, branch-circuit protection, conductor sizing, disconnect selection, controller rating, and SCCR are separate checks.

How to use this chart

1Start with FLC sourceRecord the current basis before using any overload, conductor, branch-protection, disconnect, or controller value downstream.

2Keep devices separateWrite overload, branch SC/GF protection, disconnect, controller, and conductor values on separate rows so they are not treated as one rating.

3Attach equipment checksUse the worksheet to list nameplate, listed combination, manufacturer, available fault current, utility, and AHJ items that must be verified.

Worksheet checklist. Record source basis, review gaps, and assumptions before using the chart result.

Capture calculator resultDocument full-load current, overload protection, branch SC/GF protection, protection type, conductor ampacity, disconnect, contactor, and starter values.
Capture equipment dataAdd motor nameplate, starter, overload relay, fuse or breaker class, controller rating, drive or bypass condition, and listed combination references.
Capture verification pathMark which items require adopted NEC, manufacturer, utility, available fault current, listing, or AHJ confirmation before use.

Common mistakes to avoid. Review these before turning chart current into an equipment decision.

Using the short-circuit protection screen as if it also selected overload protection, conductors, disconnects, and controller ratings.
Skipping listed combination equipment and manufacturer instructions when the motor controller or protective device requires them.
Mixing nameplate FLA, table FLC, measured current, and drive input current without labeling which value fed each protection step.

Frequently asked questions

These answers explain how to use the chart without turning a quick reference into a final design decision.

Can one calculator value size every motor protection item?

No. Overloads, short-circuit and ground-fault protection, conductors, disconnects, and controllers can use different inputs and verification paths.

Why does the worksheet ask for listed combination equipment?

Listed combinations can affect allowable devices, ratings, SCCR, and manufacturer instructions, so they must be checked before equipment selection.