SW400 400A SPST NO DC Contactor

Name: SW400 400A SPST NO DC Contactor
Brand: Newtrend or OEM
SKU: 60426200359

Description

Albright duplicate SW400 400A 12VDC 24VDC Single Pole Single Throw Normally Open SPST NO 400A DC Contactor

Application:

The SW400 has been designed by Albright for use in telecommunication and power distribution applications where the load is infrequently switched. These contactors are primarily for use with Direct Current loads, however they can also be used with Alternating Currents.
• Uninterrupted current – no or infrequent load switching requirements (maintains a lower contact resistance).

The SW400 has double breaking main contacts with silver alloy tips which are weld resistant, hard wearing and have
excellent conductivity. This compact contactor can be busbar mounted vertically or horizontally, however if mounted vertically, the coil should be at the bottom. If the coil is required at the top, we can adjust the contactor to compensate for this. Optional extras for the SW400 include auxiliary switches, brackets, coil finishes and magnetic latching – allows the contactor to remain closed
while consuming no coil power. Additionally, silver plating on the main contacts is specified as standard (option for no silver plating is also available).

Additional information

Weight	2 kg
Dimensions	25 × 25 × 25 cm
Number of Pole	1
Main Circuit Rating Voltage	12VDC, 24VDC

Technical Datasheet & Downloads

📄 Technical Documentation & Product Specifications

Download official engineering datasheets, certified test standards (IEC / UL / CE), wiring diagrams, and dimensional drawings for SW400 400A SPST NO DC Contactor.

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Official Technical Datasheet (PDF) Complete electrical ratings, tripping characteristics, dimensions, and compliance specifications.

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2D/3D CAD & Dimensional Drawings STEP, DXF, and PDF CAD drawing files for panel builders and switchgear designers.

Technical FAQ & Selection Guide

💡 Frequently Asked Technical Questions & Selection Guide

Pure engineering specifications, tripping curve parameters, and electrical selection guidance for panel builders and system designers.

AC-1 / AC-3 Duty

How to calculate contactor rating based on motor power and utilization categories (AC-1 vs AC-3 vs AC-4)?

AC-3 rating applies to standard squirrel-cage motor starting and stopping during normal run (starting current 5–7x In). For non-inductive or purely resistive heating loads, use the higher AC-1 rating. For severe inching, jogging, and plugging applications (AC-4 duty), derate the contactor or upsize by 1 to 2 frame sizes to prevent contact erosion.

Coil Voltage Selection

How to choose the correct control coil voltage, frequency, and electronic wide-voltage options?

Standard AC coils include 24V, 48V, 110V, 220V/230V, 380V at 50/60Hz. For DC control loops or PLC outputs, specify DC coils or electronic wide-range AC/DC coils (e.g. 100V–250V AC/DC) which feature built-in surge suppression, low holding power consumption, and immunity to voltage dips.

Overload Coordination

How to size and coordinate the matching thermal overload relay (TOR) for Type 2 protection?

Select a thermal overload relay whose current setting range straddles the motor full-load current (FLA). Set the dial precisely to 1.0x motor nameplate FLA. For IEC 60947-4-1 Type 2 coordination, pair the contactor and relay with backed-up upstream fuses or fast-acting MCB/MCCB to prevent welding under fault conditions.

Auxiliary & Interlocks

What auxiliary contact blocks and mechanical interlocks can be added for motor reversing?

Units feature built-in 1NO or 1NC auxiliary contacts, expandable with top-mounted 2-pole or 4-pole auxiliary contact blocks (F4 / AX) and pneumatic timer delay blocks. For forward/reverse motor starters or star-delta starter assemblies, add side-mounted mechanical interlock units (MI) with electrical interlocking.

Ambient & Altitude Derating

How do ambient temperature and installation altitude affect contactor performance?

Standard ratings are calibrated for -5°C to +40°C. For ambient temperatures exceeding 55°C or altitudes above 2000m (where reduced air density diminishes heat dissipation and dielectric insulation), derate operational current by 2% per 100m above 2000m and verify insulation voltage limits per IEC standards.