ALLEN-BRADLEY 156-B20AB1 Relay 156-B20AOB1
( Brand: Allen-bradley ), ( Manufacturer Part Number: 156-B20AB1 ), ( Model: ALLEN BRADLEY 156-B20AB1 SER A ), ( Country Of Origin: Malta ), ( Number Of Phases: 1-phase )
Review ALLEN BRADLEY Ser Relay
The **Allen-Bradley 156-B20AB1** and **156-B20AOB1** are high-performance, industrial-grade relays designed for demanding automation and control applications within manufacturing, process control, and industrial machinery environments. Part of Rockwell Automation s **156 Series** line, these relays are engineered to provide reliable switching, precise timing, and robust protection in environments where reliability and consistency are critical. The **156-B20AB1** features **normally open (NO) and normally closed (NC) contacts**, along with an **auxiliary contact** that can be configured for additional control flexibility, making it ideal for applications requiring sequential or parallel switching operations. Meanwhile, the **156-B20AOB1** offers a **normally open (NO) contact** paired with an **auxiliary contact**, providing a streamlined yet versatile solution for simpler control schemes. Both relays are housed in a compact, **IP20-rated** enclosure, ensuring protection against solid objects greater than 12.5 mm while maintaining ease of installation in standard DIN rail or panel-mount configurations.
These relays operate on a **24 VDC supply**, delivering a consistent and efficient switching mechanism with a **contact rating of 10 A at 24 VDC** (resistive load) and **5 A at 240 VAC** (inductive load), making them suitable for a wide range of control circuits, including motor starters, solenoid valves, and indicator lights. The **156 Series** is known for its **long operational lifespan**, with contact life exceeding **100,000 operations** under normal conditions, ensuring durability in high-cycle applications. Additionally, the relays incorporate **overload protection** and **thermal management** features to prevent damage from excessive current or prolonged operation, enhancing their reliability in continuous-use environments.
A defining characteristic of the **156 Series** is its **modular and scalable design**, allowing for easy integration into larger control systems through **Allen-Bradley s 1769 or 1771 series** programmable logic controllers (PLCs) or standalone use in discrete control panels. The relays feature **LED indicators** for coil power and contact status, providing immediate visual feedback for troubleshooting and system monitoring. Their **low power consumption** and **fast response time** further contribute to their efficiency, making them a preferred choice for applications where energy savings and rapid actuation are essential. Whether used in **automated assembly lines, HVAC systems, or industrial robotics**, these relays deliver the precision and dependability required to maintain seamless operation in even the most challenging industrial settings. Built to Rockwell Automation s high standards, the **156-B20AB1** and **156-B20AOB1** relays exemplify the blend of functionality, durability, and ease of integration that define modern industrial automation solutions.
### **Pros and Cons of buying a Allen-Bradley 156-B20AB1 / 156-B20AOB1 Relay**
#### **Pros:**1. **Reliability and Durability** Allen-Bradley (now part of Rockwell Automation) is a well-established brand known for high-quality industrial components. These relays are designed for harsh environments, offering long-term reliability in automation and control systems.
2. **Compatibility with PLC Systems** The 156-B20 series is specifically engineered to integrate seamlessly with Allen-Bradley PLCs (e.g., SLC, Logix, or CompactLogix), making it ideal for existing industrial setups.
3. **Wide Voltage and Current Ratings** The **156-B20AB1** (AC) and **156-B20AOB1** (DC) models support standard industrial voltage ranges (120V AC/DC to 240V AC/DC), accommodating various control applications.
4. **Compact and Space-Efficient Design** The modular form factor allows for easy installation in control panels, reducing space requirements while maintaining functionality.
5. **Low Power Consumption** These relays operate efficiently, minimizing energy waste in control circuits.
6. **Easy Replacement for Legacy Systems** If your system already uses Allen-Bradley components, these relays are a straightforward upgrade or replacement option, reducing compatibility issues.
7. **Good Availability** As a widely used industrial relay, these parts are readily available from authorized distributors, reducing lead times compared to niche or discontinued components.
8. **Standardized Pin Configuration** The wiring layout follows industry norms, simplifying troubleshooting and maintenance for technicians familiar with Allen-Bradley products.
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#### **Cons:**1. **Higher Upfront Cost** Compared to generic or aftermarket relays, Allen-Bradley components tend to be more expensive, which may be a drawback for budget-conscious projects.
2. **Potential Overkill for Simple Applications** If you only need a basic relay for a non-industrial or low-demand application, a cheaper, off-the-shelf relay (e.g., from Omron, Siemens, or a generic brand) may suffice without the premium features.
3. **Limited Customization** These relays are designed for standard industrial use and may not offer specialized features (e.g., high-speed switching, built-in diagnostics) found in high-end variants.
4. **Dependence on Brand-Specific Support** If you re not already invested in Allen-Bradley s ecosystem, you may need to rely on their technical support, which could be less responsive than for a widely used generic component.
5. **Potential for Obsolescence** While still in production, Allen-Bradley occasionally phases out older models. Future availability may depend on demand and Rockwell s product lifecycle decisions.
6. **Slightly Higher Failure Rate in Extreme Conditions** While robust, these relays may not perform as well as specialized relays in extreme temperature fluctuations, high humidity, or high vibration environments without additional protection.
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### **Conclusion**
The **Allen-Bradley 156-B20AB1 / 156-B20AOB1 relays** are excellent choices for industrial automation applications where reliability, compatibility with PLC systems, and long-term performance are critical. They are particularly well-suited for environments where existing Allen-Bradley infrastructure is in place, or where high-quality, standardized components are a priority.
However, if cost is a major concern or if the application is simple and non-industrial, a more affordable generic relay might be a practical alternative. Additionally, if you anticipate extreme operating conditions, consider pairing these relays with protective enclosures or consulting Rockwell s technical documentation for optimal use.
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### **Recommendation**
**Buy the Allen-Bradley 156-B20 series if:**- You are working with an existing Allen-Bradley PLC system and need seamless integration.
- Reliability and long-term performance are non-negotiable for your industrial application.
- You require a standardized, widely supported component with good availability.
- Your budget allows for the premium pricing of a trusted brand.
**Consider alternatives if:**- Your application is low-cost or non-industrial, and a generic relay would work just as well.
- You need specialized features (e.g., high-speed switching, diagnostics) not offered by this model.
- You are operating in extreme conditions where additional protection (e.g., enclosures, filters) is required.
For most industrial automation projects where compatibility and durability are key, these relays remain a strong recommendation. Always verify the exact model requirements (voltage, current, contact type) with your application specifications before purchasing.
Details:
This relay is designed to operate in a 1-phase configuration, making it suitable for controlling the power various motors and equipment industrial automation systems. The ALLEN BRADLEY 156-B20AoB1 ser A RELAY is a specific type of industrial automation component produced by Allen-Bradley, well-known brand in the field motion control systems. With its reliable performance and compatibility with a range of Allen-Bradley products, this relay is valuable component for ensuring efficient precise control in variety industrial settings.
part #: 156b20ab1 prices
- $60.00-$120.00
specifications variablfrequen:
- brand: Allen-bradley
- mpn: 156-b20ab1
- model: Allen Bradley 156-b20ab1 Ser A
- country of origin: Malta
- number of phases: 1-phase
shipping variablfrequen:
- service: USPS Ground Advantage
- transit: 3-8 Days
- carrier: USPS
- type: Calculated
- cost: $9.42
- class: Standard
offer variablfrequen:
- availability: In Stock
- started: June 1, 2026
- best offers: True
- sold: 0
- options: Ship-to-home
- quantity: 1
seller variablfrequen:
- city: Plant City, Florida
- rating: 100.0%
- # reviews: 36
payments variablfrequen:
- other
- credit card: Visa
- wallet: Google-pay
general variablfrequen:
- Drives Starters > Drives Motor Controls > Variable Frequency Drives
- condition: Used
returns variablfrequen:
- policy: No Returns
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