Direction of Rotation of Three-Phase Motor Hampden Lab Manual

The Hampden Lab Three-Phase Motor Rotation Manual provides comprehensive guidance on determining, testing, and controlling the rotational direction of three-phase induction motors. This manual covers motor specifications, wiring configurations, phase sequence testing, rotation reversal methods, safety procedures, and troubleshooting techniques for industrial and educational applications.

1. Motor Specifications 2. Safety Precautions 3. Phase Sequence Fundamentals 4. Rotation Testing Procedures 5. Wiring Configurations 6. Direction Reversal Methods 7. Lab Equipment Setup 8. Measurement Techniques 9. Common Applications 10. Troubleshooting Guide

Motor Specifications

Hampden three-phase motor technical details and operating parameters.

Parameter	Specification
Motor Type	Three-Phase Induction Motor
Power Rating	1-5 HP (depending on model)
Voltage	208-240V AC, 3-Phase
Frequency	50/60 Hz
Speed	1750 RPM (60Hz) / 1450 RPM (50Hz)
Enclosure	TEFC (Totally Enclosed Fan Cooled)
Insulation	Class F
Bearings	Double-shielded ball bearings
Mounting	NEMA standard foot mounting
Rotation	Clockwise/Counterclockwise (reversible)

Safety Precautions

Essential safety measures for working with three-phase motors.

Always disconnect power before handling motor connections.
Use appropriate PPE: safety glasses, insulated gloves, protective clothing.
Ensure proper grounding of all electrical equipment.
Verify phase sequence before initial startup.
Keep work area clean and dry to prevent electrical hazards.

WARNING! Three-phase motors operate at high voltages; improper handling can cause severe injury or death. Always follow lockout/tagout procedures.

Phase Sequence Fundamentals

Understanding phase sequence and its impact on motor rotation direction.

Three-phase systems: L1, L2, L3 phases with 120° separation.
Standard sequence: L1-L2-L3 (ABC) for clockwise rotation.
Reverse sequence: L1-L3-L2 (ACB) for counterclockwise rotation.
Use phase sequence meter to verify correct phase order.
Visual indicators: motor shaft rotation direction markings.

CAUTION! Incorrect phase sequence can damage connected equipment and cause unsafe operating conditions.

Rotation Testing Procedures

Visual Inspection: Check motor nameplate for rotation direction.
Phase Sequence Testing: Use phase sequence meter to verify L1-L2-L3 order.
Bump Testing: Momentary power application to observe rotation direction.
Directional Markings: Verify shaft rotation matches indicated direction.
Load Testing: Confirm proper rotation under loaded conditions.
Instrumentation: Tachometer for speed verification.
Documentation: Record test results for future reference.

Wiring Configurations

Motor terminal connections for different rotation directions.

Standard Rotation (Clockwise): Connect phases L1-T1, L2-T2, L3-T3

Reverse Rotation (Counterclockwise): Swap any two phases: L1-T1, L2-T3, L3-T2

Star (Wye) Configuration: Connect U2, V2, W2 together; U1, V1, W1 to phases

Delta Configuration: Connect U1-W2, V1-U2, W1-V2; apply phases to junctions

Direction Reversal Methods

Techniques for changing motor rotation direction.

Phase swapping: Interchange any two phase conductors.
Control circuit: Use forward/reverse contactors in control panel.
VFD programming: Configure rotation direction in variable frequency drive.
Manual switches: Install rotation selector switches.
PLC control: Programmable logic controller for automated direction changes.

Tip: Always stop motor completely before changing rotation direction to prevent damage.

Lab Equipment Setup

Required equipment for three-phase motor rotation experiments.

Three-phase power supply: 208-240V AC, properly grounded.
Hampden three-phase motor with base mounting.
Phase sequence meter and rotation direction indicator.
Multimeter for voltage and continuity testing.
Motor starter with overload protection.
Forward/reverse contactor setup.
Tachometer for speed measurement.
Safety disconnect switch with lockout capability.

WARNING! Ensure all equipment is properly rated for three-phase operation and installed by qualified personnel.

Measurement Techniques

Proper measurement procedures for motor rotation analysis.

Measurement	Instrument	Procedure
Phase Voltage	Multimeter	Measure between phases L1-L2, L2-L3, L3-L1
Phase Sequence	Phase Meter	Connect to L1, L2, L3; observe indicator
Rotation Speed	Tachometer	Apply to motor shaft; record RPM
Current Draw	Clamp Meter	Measure each phase current under load
Direction	Visual/Strobe	Observe shaft rotation; use directional marks

Common Applications

Industrial applications requiring specific rotation directions.

Pumps: Centrifugal pumps require specific rotation for proper operation
Fans/Blowers: Direction affects airflow and cooling efficiency
Conveyors: Material handling direction depends on rotation
Machine Tools: Lathes, mills require controlled direction
Compressors: Rotation affects compression cycle and efficiency
Hoists/Cranes: Lifting/lowering controlled by motor direction

Troubleshooting Guide

Problem	Possible Cause	Corrective Action
Motor rotates wrong direction	Incorrect phase sequence	Swap any two phase connections
Motor won't start	Open phase or overload	Check all phases; reset overloads
Uneven rotation	Single phasing	Verify all three phases present
Overheating	Wrong rotation under load	Check direction; verify application requirements
Vibration/noise	Mechanical issues	Check alignment, bearings, balance

Reset: Disconnect power, check wiring, restart system.

Technical Support: Contact Hampden Engineering at 1-800-777-0725 or visit www.hampden.com