CADXChange

ResourcesElectrical schematic symbolsMotor control circuit diagram

Variable frequency drive

A 15 kW pump on a variable frequency drive: breaker, frequency converter, screened motor cable and motor, with the drive control terminals wired to a run switch, a speed potentiometer, a dual-channel emergency stop for safe torque off, the motor thermistor, two relay-output lamps and a panel ammeter.

Free to use and modify in your own projects, including commercial ones. The ZIP holds the sample drawing, a template, a plot style table and a README; no add-in needed. The data in the drawing is made up, so it is not for design or construction. Provided as is, without warranty. Library terms (CXL-1.0)

Version 1.0 · updated October 21, 2026

This sample uses these resources

The symbols are blocks from our own libraries, with their attributes filled in. The sheet and its title block come from our ISO A3 title block template. Download them to draw your own diagrams.

Layers, styles and sheet setup are the same for every drawing in the series; they are described on the series page: Motor control circuit diagram

Title block fields

The attributes of the title block. Double-click it to fill them in, or write them for a whole set of drawings with BlockSync.

AttributeField on the sheetValue in this sample
COMPANYCOMPANYCADXChange
PROJECTPROJECTPump Station Motor Control
AREAAREAPump station
SYSTEMSYSTEM400 V / 230 V
CLIENTCLIENTSample
TITLEDRAWING TITLEMotor starter, variable frequency drive
DRAWING_NODRAWING NO.E-105
CONTRACT_NOCONTRACT NO.—
REVREVA
DRAWNDRAWN—
CHECKEDCHECKED—
APPROVEDAPPROVED—
DATEDATE2026-10-22
SCALESCALENTS
SHEETSHEET1
SHEET_OFOF1

Revision table: R1 to R4, each with REV, DATE, DESCRIPTION and BY (16 attributes, empty in this sample).

Blocks in the drawing

The equipment list of the drawing: block name, symbol and how many times it is placed. BlockSync exports the same list from your own drawings.

SymbolBlockPlaced
JunctionIEC_JUNCTION8
TerminalIEC_TERMINAL2
Signal lampIEC_LAMP2
Circuit-breaker, 3-poleIEC_CIRCUIT_BREAKER_3P1
Frequency converterIEC_FREQUENCY_CONVERTER1
Motor, three-phaseIEC_MOTOR_3PH1
Earth (ground)IEC_EARTH1
Selector switch, NOIEC_SELECTOR_NO1
Emergency stop, NCIEC_ESTOP1
Auxiliary contact, NCIEC_AUX_CONTACT_NC1
PotentiometerIEC_POTENTIOMETER1
Thermistor, PTCIEC_THERMISTOR_PTC1
FuseIEC_FUSE1
AmmeterIEC_AMMETER1

Equipment schedule

One row per placed symbol, read from the attributes of the blocks in the drawing: what is shown on the sheet, and the schedule attributes that were filled in but are not shown. BlockSync exports these same attributes from your own drawings.

TagDescriptionShown on the sheetFilled in, not shown
Q1Circuit-breaker, 3-poleIEC_CIRCUIT_BREAKER_3PRATING_A = C40POLES = 3CURVE = CBREAKING_KA = 10VOLTAGE = 400 V
VFD1Frequency converterIEC_FREQUENCY_CONVERTERPOWER_KW = 15 kWINPUT_V = 400 V 3~OUTPUT_HZ = 0-50 HzOUTPUT_A = 32 APROTECTION = IP21
M1Motor, three-phaseIEC_MOTOR_3PHPOWER_KW = 15 kWVOLTAGE = 400 VCURRENT = 28 ASPEED_RPM = 1470FREQUENCY = 50 Hz
PE1Earth (ground)IEC_EARTHEARTH_TYPE = PE
S1Selector switch, NOIEC_SELECTOR_NOCONTACT_NO = 3-4LEGEND = RUNPOSITIONS = 2RATING_A = 10
SB0Emergency stop, NCIEC_ESTOPCONTACT_NO = 11-12LEGEND = E-STOPCOLOR = RedRATING_A = 10
SB0Auxiliary contact, NCIEC_AUX_CONTACT_NCCONTACT_NO = 21-22RATING_A = 10OPERATING_DEVICE = SB0
RP1PotentiometerIEC_POTENTIOMETERVALUE = 10 kohmPOWER = 0.5 W
RT1Thermistor, PTCIEC_THERMISTOR_PTCVALUE = 130 CTRIP_C = 130TYPE = PTC
X2TerminalIEC_TERMINALTERMINAL_NO = 1
F2FuseIEC_FUSERATING_A = 4 AVOLTAGE = 230 VCLASS = gGBREAKING_KA = 50
X2TerminalIEC_TERMINALTERMINAL_NO = 2
HL1Signal lampIEC_LAMPCOLOR = GNVOLTAGE = 230 V ACPOWER = 2 W
HL2Signal lampIEC_LAMPCOLOR = RDVOLTAGE = 230 V ACPOWER = 2 W
PM1AmmeterIEC_AMMETERRANGE = 0-40 AACCURACY_CLASS = 1.5

Manufacturer, model and remarks are left empty on every block, ready for your data. The values are examples.

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