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400A DC Contactor, 12V/24V/48V/220V

5 out of 5 based on 2 reviews | Write a review

$158.61

Single pole DC contactor with 12V, 24V, 48V, 220V coil voltage for choice, has one normal open contact (SPST 1NO), contact circuit rated load current of 400A, offers exceptional performance in an extremely small and lightweight device. 400A DC contactor is suitable for switch control of system circuits such as battery cars, cleaning cars, communication power supplies and automobile air conditioners.

Coil Rated Voltage *

With Auxiliary Contact *

1NO+1NC [+$20.56]

SKU: ATO-DCCON-C400

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Delivery date: 2-12 days

Overview
Related Video

High performance 400A DC contactor with normally open type. This 400 amps contactor is available in coil voltage 12V, 24V, 48V, 220V. 400A DC contactor with high-performance quality, low cost and manufacturer direct sale. The single pole 400A DC contactor is suitable for switch control of electric circuits such as electric forklifts, battery trucks, tractors, excavators, brick making machines, etc.

Features

400A DC contactor has the characteristics of small size, large load capacity, long service life and simple maintenance, and is very popular among users.
400 amps contactor complies with the requirements of the ministry standards JB2286-78, JB3974-85, YD/585-92, YD/T512-92. It has been tested in the factory and by relevant testing units and meets the requirements of the ministry standards. It has been used by users for many years to satisfy users to the maximum extent. Needed, reliable quality.
Single coil 400A DC contactor are suitable for electric forklifts, battery trucks, tractors, excavators, brick making machines, cleaning vehicles, automotive air conditioners, communication power supplies, switch control of electronic control circuits of uninterruptible power supplies, electroplating power supplies and other systems.

Specifications

Model	ATO-SZJ400A-D
Contact Form	Normally open
Coil Rated Voltage (DC V)	12V, 24V, 36V, 48V, 60V, 72V, 84V, 120V, 150V, 220V
Contact Rated Voltage (DC V)	≤80V
Contact 48V Circuit Rated Load Current (DC-1)	400A
Main Contact Contact Voltage Drop under 100A Load	≯80mV
Cooling pull-in voltage (V), (20±5)℃	≯70%
Cooling Release Operating Voltage (V), (20±5)℃	≯35%, ≮5%
40℃ Coil Operating Voltage Range	0.8-1.2Us
Power-on Action Time	35ms
Power off Release Time	10ms
Maximum Bounce Time of Contact Connection	10ms
Maximum Bounce Time of Contact Disconnection	3ms
Insulation Resistance	20MΩ
Dielectric Strength	50Hz/60Hz 1000VAC 1minute
Maximum Breaking Capacity of Main Contact (Power on for 5ms)	1000A/5ms at 48V/DC
Coil Power Consumption (W)	9-18
Coil Temperature Rise (K)	≤60
Terminal Temperature Rise (K)	≤65
Electrical Life	20000times
Mechanical Life	300,000 times
Work Specifications	Continuous
Contact Material	Silver alloy
Load Terminal Type	M10 screw
Coil Terminal Type	M4 screw
Auxiliary Contact Rated Load (Optional)	2A/48VDC, 5A/24VDC
Testing Agency Certification	CCC, CE, FCC, RoHS

Load Characteristic Curve

Installation Dimension Diagram

400A DC contactor installation dimension drawing

400A DC contactor micro installation dimension drawing

400A DC contactor e2 installation dimension drawing

SZJ400A-D Wiring Diagram & Coil Temperature Rise Curve Graph

400A DC contactor d wiring diagram

One way is normally open (SPST 1NO)
1 and 2 are contact terminals
A1 and A2 are coil terminals

Mechanical Capabilities and Usage Environment

Contact Terminal M8 Tightening Torque (Nm)	≯20.5 is appropriate
Coil Lead-out M4 Tightening Torque (Nm)	≯1.2 is appropriate
Ambient Temperature	-25~+70℃
Relative Humidity	+20℃ 98%
Vibration Frequency at Fixed Location	3G, 1～50Hz, amplitude 0.5mm
Impact	(60～100) times/min, acceleration ≤4g
Altitude	2000 meters
Installation Direction	Arbitrary
Protection Level	IP40 (equivalent to IEC60947)

Tips: How to judge the quality of DC contactor?

Appearance: Check the DC contactor for abnormal wear, deformation or corrosion.
Electrical performance: Use a multimeter or rack test equipment to test the continuity of the circuit and check for damage or open circuits.
Mechanical performance: Check the sensitivity, operating force and reset condition of the DC power contactor switch to see if there are any problems that are too large or too small.
Insulation performance: Test the DC contactor to check whether there is leakage or load current drop.
DC contact material: The material of the contacts determines the service life of the DC power contactor. The cost of really good contacts is relatively high and is made of silver alloy. Some inferior contacts are made of copper alloy, or a layer of silver is electroplated on the copper contacts. Alloys have a very short service life.

Electromagnetic Switches: Relays VS. Contactors

In this video we will try to clear the confusion many people have between relays and contactors by showing you how to tell the difference based on five criteria: Definition, Capacity, Structure, Contacts and Applications.

Existing reviews of 400A DC Contactor, 12V/24V/48V/220V

Contactor contacts

Why does the specification indicate that the ATO-SZJ400A-D contactor does not have the option to add auxiliary contacts?

From: Bafidar | Date: 17/10/2025

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ATO Responded

The ATO-SZJ400A-D contactor can be configured with auxiliary contacts, located on the top of the contactor. We can configure it with 1 NO + 1 NC auxiliary contacts.

Perfect DC contactor

I needed a solid contactor for my 48V solar battery bank, and this 400A DC contactor is just right. The best part is it sips power—since it's energized all the time, I don't have to worry about it draining my batteries. I was also really happy to see that the voltage drop is as low as they promised. It just works perfectly, no fuss. Really glad I picked this one!

From: Avra | Date: 01/09/2025

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