4 Motor Contactors
Last Updated: April 1, 2025
Description
A 4-pole motor contactor is an electrical device designed to control the power flow to motors by opening and closing electrical circuits. It typically consists of a 40 amp, 240 V coil and is available in both standard and low consumption versions. The contactor is part of a motor starter system that includes overload protection to prevent excessive current draw during motor startup.
Working Principle
Motor contactors operate using an electromechanical mechanism. When the coil within the contactor is energized, it generates a magnetic field that pulls the contactor's contacts together, allowing electrical current to flow through the circuit and power the motor. This mechanism is crucial for protecting motors from damage due to overloads or electrical faults by ensuring that the motor only operates under safe conditions. The contactor's ability to quickly and reliably open and close circuits makes it an essential component in motor control systems.
Applications
4-pole motor contactors are used in various industrial and commercial applications where precise control of motor operation is required. They are commonly found in HVAC systems, conveyor belts, and manufacturing equipment. For example, in an HVAC system, a motor contactor can control the operation of compressors and fans, ensuring efficient temperature regulation. In manufacturing, they are used to control the operation of machinery, such as pumps and mixers, to maintain consistent production processes.
Advantages over other Motor Contactors
One advantage of 4-pole motor contactors is their ability to handle a wider range of current selections, making them suitable for applications requiring higher power capacities. This flexibility allows them to be used in more demanding environments compared to 2-pole or 3-pole contactors. Additionally, their design includes both standard and low consumption versions, providing options for energy efficiency and cost savings.
Limitations
Despite their advantages, 4-pole motor contactors have limitations. They may require more space due to their larger size compared to 2-pole or 3-pole contactors. Additionally, the initial cost of a 4-pole contactor can be higher, which might not be justified for applications with lower power requirements.
Considerations
When selecting a 4-pole motor contactor, it is important to consider factors such as initial costs, operating expenses, and maintenance requirements. While they offer durability and reliability, the initial investment can be significant. Operating expenses may be reduced with low consumption versions, but regular maintenance is necessary to ensure long-term performance and prevent unexpected failures. Replacement costs should also be factored into the overall cost of ownership, as contactors may need to be replaced periodically due to wear and tear.
from Altech Corp.
Features: 8 Frame Sizes. 1/2HP up to 600HP @ 480V AC. Direct Mounting Overload Relays. Degree of protection:IP20. Flame Resistance:According to UL948 [See More]
- NEMA Size: 4
- Device Technology: Electro-mechanical
- Standard Rating: NEMA; IEC
- AC Motor Phase: Single
from Allen-Bradley / Rockwell Automation
281 Safety Reversing Starter, NEMA Type 4/IP67 Enclosure, DeviceNet, 12 A Safety Contactor w/ 24V DC Control Voltage, 10 A Rated Device - Motor Circuit Protector, 0.5-2.5 A Overload Relay, , Conduit Entrance with Motor Cable Supplied [See More]
- NEMA Size: 4
- Standard Rating: NEMA
from Radwell International
CONTACTOR, 3 PHASE, OPEN TOP WIRE CONTACTOR, 3 POWER POLES, 240 VAC, 60 HZ, NO OPTION, NEMA 4, 220 VAC @ 50 HZ, 240 VAC @ 60 HZ, 50 HP. FREE 2 YEAR RADWELL WARRANTY [See More]
- NEMA Size: 4
- AC Motor Phase: Three
- Standard Rating: NEMA
- Motor Voltage: 220 to 240
from Allen-Bradley / Rockwell Automation
284D ArmorStart Safety Distributed Motor Starter, NEMA Type 4/IP67 Enclosure, DeviceNet, 25 A Rated Device - Motor Circuit Protector, Conduit Entrance with Motor Cable Supplied, [See More]
- NEMA Size: 4
- Standard Rating: NEMA
from Radwell International
DISCONTINUED BY MANUFACTURER, COIL, 460/480 VAC, 50/60 HZ, NEMA 4, RATED 300 AND 200 LINE, MAGNETIC CONTACTORS AND STARTERS. FREE 2 YEAR RADWELL WARRANTY [See More]
- NEMA Size: 4
- Motor Voltage: 480
- Standard Rating: NEMA
from Allen-Bradley / Rockwell Automation
NEMA Combination Contactor, Circuit Breaker Type, NEMA 0, 480 Volts (B), Type 4/4X - Enclosure Code C"" [See More]
- NEMA Size: 0; 4
- Control Voltage: 120
- Standard Rating: NEMA
from Radwell International
DISCONTINUED BY MANUFACTURER 2007-02-28, OVERLOAD RELAY, SOLID STATE, MANUAL RESET, 23/75AMP, 3 PHASE, CLASS 20, NEMA 4, ELECTRONIC, NEMA, SMP-1, MANUAL RESET, MOUNTS TO NEMA SIZE 4 CONTACTOR, 1 NORMALLY CLOSED O UTPUT. FREE 2 YEAR RADWELL WARRANTY [See More]
- NEMA Size: 4
- Device Technology: Solid State
- Standard Rating: NEMA
- AC Motor Phase: Three
from Allen-Bradley / Rockwell Automation
NEMA Combination Contactor, Disconnect Type, NEMA 0, 480 Volts (B), Type 4/4X - Enclosure Code C"" [See More]
- NEMA Size: 0; 4
- Control Voltage: 120
- Standard Rating: NEMA
from Allen-Bradley / Rockwell Automation
NEMA Combination Contactor, Disconnect Type, NEMA 0, 240/110/120 VAC - 50/60Hz (AD), Type 4/4X - Enclosure Code C"" [See More]
- NEMA Size: 4
- Standard Rating: NEMA
from Allen-Bradley / Rockwell Automation
NEMA Combination Contactor, Circuit Breaker Type, NEMA 0, 240/110/120 VAC - 50/60Hz (AD), Type 4/4X - Enclosure Code C"" [See More]
- NEMA Size: 4
- Control Voltage: 120
- Standard Rating: NEMA
from Allen-Bradley / Rockwell Automation
NEMA Combination Lighting Contactor, Circuit Breaker Type, 15 A Tungsten/ 20 A General, 480 Volts (B), Type 4/4X - Enclosure Code C"" [See More]
- NEMA Size: 4
- Standard Rating: NEMA
from Allen-Bradley / Rockwell Automation
NEMA Contactor,Motor Loads,Top Wiring,SIZE 1,460-480V 60Hz,Type 4/4X Watertight, Corrosion-Resistant Enclosure, Stainless Steel, 3 Power Poles [See More]
- NEMA Size: 1; 4
- Number of Poles: 3
- Standard Rating: NEMA
from Allen-Bradley / Rockwell Automation
NEMA Combination Lighting Contactor, Disconnect Type, 30 A, 240 Volts (A), Type 4/4X - Enclosure Code C"" [See More]
- NEMA Size: 1; 4
- Standard Rating: NEMA
from Allen-Bradley / Rockwell Automation
NEMA Combination Lighting Contactor, Circuit Breaker Type, 100 A, 240/110/120 VAC - 50/60Hz (AD), Type 4/4X - Enclosure Code C"" [See More]
- NEMA Size: 3; 4
- Continuous Current: 100
- Standard Rating: NEMA
- Control Voltage: 120
from Allen-Bradley / Rockwell Automation
NEMA Combination Contactor, Circuit Breaker Type, NEMA 4, 480 Volts (B), Type 4/4X - Enclosure Code C"" [See More]
- NEMA Size: 4
- Control Voltage: 480
- Standard Rating: NEMA
from Allen-Bradley / Rockwell Automation
300 NEMA Contactor, NEMA Size 4, Open, 100-250V 50-60 Hz/100-250V DC With 24V DC PLC Interface, Three NO Poles, 1 N.O. - 1 N.C. Auxiliary Contact [See More]
- NEMA Size: 4
- Standard Rating: NEMA
from Allen-Bradley / Rockwell Automation
500FL NEMA Feed-Through Wiring Electrically Held Lighting Contactor ,200A, Open, 230-240V 60Hz, 2 Power Poles , 230-240V 60Hz , [See More]
- NEMA Size: 4
- Continuous Current: 200
- Standard Rating: NEMA
- Number of Poles: 2
from Allen-Bradley / Rockwell Automation
500FL NEMA Feed-Through Wiring Electrically Held Lighting Contactor ,200A, Open, 115-120V 60Hz, 2 Power Poles , 115-120V 60Hz , [See More]
- NEMA Size: 4
- Continuous Current: 200
- Standard Rating: NEMA
- Number of Poles: 2
from Allen-Bradley / Rockwell Automation
500LP NEMA Top Wiring Permanent Magnetic-Latching Lighting Contactor ,200A, Open, 115-120V 60Hz, 3 Power Poles, No , 115-120V 60Hz , [See More]
- NEMA Size: 4
- Continuous Current: 200
- Standard Rating: NEMA
- Number of Poles: 3
from Allen-Bradley / Rockwell Automation
500LP NEMA Top Wiring Permanent Magnetic-Latching Lighting Contactor ,200A, Open, 115-120V 60Hz, 3 Power Poles, No , 115-120V 60Hz , Auxiliary Contact (On Contactor) [See More]
- NEMA Size: 4
- Continuous Current: 200
- Standard Rating: NEMA
- Number of Poles: 3
from Allen-Bradley / Rockwell Automation
500F, 500FC NEMA AC/DC Contactor,Motor Loads,Feed-Through ,SIZE 4, Open, 115-120V 60Hz, 3 Power Poles, Yes , 135 , 110/120V 50/60 Hz , [See More]
- NEMA Size: 4
- Continuous Current: 135
- Standard Rating: NEMA
- Number of Poles: 3
from Allen-Bradley / Rockwell Automation
300S Safety Contactor, NEMA Size 4, Open, 250-500V 50-60 Hz/250-500V DC With 24V DC PLC Interface, Three NO Poles, 1 N.O. - 1 N.C. Auxiliary Contact [See More]
- NEMA Size: 4
- Standard Rating: NEMA
from Allen-Bradley / Rockwell Automation
500F, 500FC NEMA AC/DC Contactor,Motor Loads,Feed-Through ,SIZE 4, Open, 115-120V 60Hz, 3 Power Poles, Yes , 135 , 110/120V 50/60 Hz , Surge Suppressor [See More]
- NEMA Size: 4
- Standard Rating: NEMA
from Allen-Bradley / Rockwell Automation
500, 500DC NEMA AC/DC Contactor, Motor Loads,Top Wiring ,SIZE 4,115-120V 60Hz,Open, 3 Power Poles , 135, 110/120V 50/60 Hz , , Yes, Surge Suppressor [See More]
- NEMA Size: 4
- Standard Rating: NEMA
from Allen-Bradley / Rockwell Automation
500L NEMA Enclosed Lighting Contactors, NEMA 0, Type 4/4X Watertight, Corrosion-Resistant, Stainless Steel, External Reset, Door Screw Fasteners, 115-120V 60Hz, 3 Power Poles, Yes , 115-120V 60Hz , Pilot Lights [See More]
- NEMA Size: 4
- Number of Poles: 3
- Standard Rating: NEMA
from CARLO GAVAZZI Automation Components
Carlo Gavazzi offers a complete range of Contactors and Overloads for switching currents up to 900 Amps (600 HP @ 480 VAC). All contactors are available with a wide selection of coil voltages and come standard with built-in auxiliary outputs. Interlock and wiring kits are available to turn 2... [See More]
- NEMA Size: 3; 4; 5; 6; 7
- Device Technology: Electro-mechanical
- Standard Rating: NEMA
- AC Motor Phase: Single (optional feature); Three