ABB 444783-210747 Modular Auxi...
IN STOCK (leaves warehouse same day if ordered before 3pm ET)
$21.96
ABB 444783-210747 Modular Auxiliary Contact Block, 2-Across

ABB 444783-210747 Modular Auxiliary Contact Block, 2-Across

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Model: MCB-01

In Stock (leaves warehouse same day if ordered before 3pm ET)

$21.96
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ABB 444783-210747 Modular Auxiliary Contact Block, 2-Across

The ABB 444783-210747 Modular Contact Block, 2-Across, 1 N.O. is a modular auxiliary contact block designed to add field-configurable auxiliary switching to compatible ABB contactors, motor starters, and pushbutton devices. Featuring a 2-across contact arrangement with 1 normally-open (N.O.) contact, this block lets panel builders and electricians expand signaling, interlocking, and indication functions on existing ABB control components without replacing the base device. It ships individually packaged (1 ea), making it easy to stock for spares, field upgrades, or building out a custom auxiliary contact configuration on an ABB contactor or starter assembly.

Key Features

  • Contact Configuration: 2-across arrangement with 1 N.O. contact, providing dependable auxiliary switching and interlocking for control and signaling circuits.
  • Modular, Snap-On Design: Mounts directly onto compatible ABB contactors, starters, and control devices, allowing auxiliary contacts to be added, changed, or expanded in the field without rewiring or replacing the base unit.
  • Space-Saving Layout: The 2-across format keeps additional auxiliary contacts compact within the control panel or enclosure footprint, simplifying panel layout.
  • Field-Configurable Auxiliary Switching: Supports common control tasks such as status indication, interlocking, and signaling alongside the main contactor or starter contacts.
  • Individually Packaged: Supplied 1 ea, suitable for single-unit replacement, maintenance spares, or building out a custom contact configuration on an existing device.

Technical Specifications

  • Refer to manufacturer documentation for complete technical specifications.

Typical Applications

  • Contactor and Motor Starter Auxiliary Contacts
  • Control Circuit Interlocking and Signaling
  • Motor Control Center (MCC) Panels
  • Industrial Automation and Control Panels
  • Panelboard and Control Wiring Upgrades
  • Maintenance Replacement for Existing ABB Contact Blocks

Why ABB?

ABB modular contact blocks are engineered to snap directly onto compatible ABB control devices, giving panel builders and maintenance electricians a simple way to add or reconfigure auxiliary contacts without replacing the base contactor or starter. The 2-across, 1 N.O. configuration provides dependable auxiliary switching for control, signaling, and interlocking circuits in industrial and commercial installations. Because the block is individually packaged and designed for compatibility with existing ABB control components, it supports both new panel builds and ongoing maintenance of installed ABB equipment. Choosing ABB components helps keep control panels consistent, modular, and easy to service over the life of the installation.

Manufacturer Resources

Spec Sheet

Product Specs

Product Type:
Contact Block
Configuration:
2-Across
Department:
Electrical
Product Group:
Motor Control & Automation
Product Subgroup:
Contactors & Relays

ABB MCB-01 – Frequently Asked Questions

1) Does the ABB modular auxiliary contact block come in a normally closed version, or only normally open?
Both. The ABB modular contact block is ordered by contact configuration: MCB-10 is the 1 N.O. version and MCB-01 is the 1 N.C. version. Pick N.O. when you want the auxiliary contact to close with the coil (run indication, seal-in, signaling), and N.C. when you want it to open on energize, which is what you use for electrical interlocking between two contactors so both cannot pull in at once.
2) Can I add auxiliary contacts to an ABB contactor without replacing the contactor?
That is exactly what this block is for. The ABB modular contact block snaps directly onto compatible ABB contactors, motor starters, and pushbutton devices, so you add or change auxiliary switching in the field without rewiring or swapping the base unit. It is the usual fix when a panel needs one more status or interlock contact than the starter shipped with.
3) Will an ABB modular contact block fit a Square D or Allen-Bradley starter?
No. It mounts on compatible ABB contactors, starters, and control devices only. Auxiliary blocks are brand and family specific in both the snap-on geometry and the actuator travel, so a different manufacturer's starter needs that manufacturer's block. For a Square D pushbutton station, the add-on block we carry is the Square D Harmony XAC ZB2BE101, 1 NO with screw clamp terminals.
4) Can a Square D Harmony XAC contact block be used in place of an ABB 444783-210747 contact block?
Not as a direct swap on ABB equipment. The ABB 444783-210747 is a modular auxiliary contact block that snaps directly onto compatible ABB contactors, starters, and pushbutton devices, so it is matched to the ABB base device it mounts on. The Square D ZB2BE101 add-on contact block belongs to the Harmony XAC series and is built for Square D Harmony operators, using a screw clamp terminal. Both provide a single normally-open auxiliary contact, but each mounts to its own manufacturer's base device, so choose the block that matches the hardware already in the panel.
5) I need a normally-closed auxiliary contact instead of normally-open. What are my options?
Stay within the ABB modular contact block family and order the MCB-01, which carries a 1 N.C. contact in the same 2-across configuration as the MCB-10 with its 1 N.O. contact. Both mount the same way on the compatible ABB base device, so the only change is the contact state. The Square D ZB2BE101 is a 1 NO block, so it will not cover a normally-closed requirement even on Square D operators.
6) What does 2-across mean on an ABB auxiliary contact block?
It describes how the block sits on the base device: the contact positions are arranged two side by side rather than stacked, which keeps the added auxiliary contacts inside the existing footprint of the contactor in the panel. Each ABB 444783-210747 block carries one contact, either N.O. or N.C. depending on which you order.
7) Is this an add-on block for a pushbutton or for a contactor?
Either, on the ABB side. The same modular block is used to expand auxiliary switching on ABB contactors and motor starters and on ABB pushbutton devices. If your application is strictly a pushbutton or selector station from another line, the Square D Harmony XAC ZB2BE101 is a pushbutton-family add-on block with a 1 NO contact and screw clamp terminals.
8) What do I order to replace a failed auxiliary contact on an existing ABB MCC bucket?
Match the contact state of the one you are pulling out. A closed-on-energize auxiliary is the MCB-10 (1 N.O.); an open-on-energize auxiliary is the MCB-01 (1 N.C.). Both are ABB modular blocks sold one per package, which suits carrying them as MCC and control panel spares.
9) What is the difference between the ABB 444783-210747 block and a Square D ZB2BE101 add-on contact block?
They serve the same control function from two different device ecosystems. The ABB 444783-210747 is a 2-across modular auxiliary block with one N.O. contact that snaps onto compatible ABB contactors, starters, and control devices to add signaling, interlocking, and indication without replacing the base unit. The Square D ZB2BE101 is a Harmony XAC add-on contact block with one NO contact and screw clamp terminals, intended for Square D Harmony operator assemblies. Match the block to the brand of the device it stacks onto.
10) Where do I find the full electrical ratings for the ABB 444783-210747 contact block?
ABB publishes the detailed electrical data for this modular contact block in its own spec sheet, linked with the product record. Use that document when you need the contact current and voltage ratings to size your control circuit; the block itself is identified by configuration, 2-across with a single N.O. or N.C. contact.
How fast can I get the ABB MCB-01 delivered?
Most orders ship the same day from our distribution partners, with quick delivery throughout the continental U.S. Need it urgently? Contact Us for expedited shipping options.
Can I return it if it doesn’t work for me?
Yes—ZenSupply offers a hassle-free return policy. If the product isn’t the right fit, reach out to our support team for a return authorization or setup a return by following our return instructions.
Does the ABB MCB-01 come with a warranty?
Absolutely. The ABB MCB-01 is backed by a manufacturer’s warranty. For full warranty terms, check the product documentation or Contact Us.
How do I get technical support or installation help for the ABB MCB-01?
You can call, text, or email our expert support team for fast answers. We’re here to help with product selection, installation tips, and troubleshooting. Contact Us
Why buy the ABB MCB-01 from ZenSupply?
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