ABB 90.21 relay

Product Overview

The 90.21 series is ABB's classic universal relay product line, developed with the concept of "standardized design and multi scenario adaptation". As a key intermediate component in industrial control circuits, its core function is to receive weak control signals (such as sensor signals, PLC output signals) and control the contact action through electromagnetic drive or solid-state triggering, achieving on/off control or signal transmission for subsequent load circuits. This series of relays can work stably in complex industrial environments by enhancing electrical isolation and anti-interference performance. It also supports seamless cooperation with ABB contactors, circuit breakers, terminal blocks, and other components to build a complete control link from signal acquisition to load driving, adapting to the control needs of different industries.

Unlike the previously focused specialized timer relays, the 90.21 series covers various types such as electromagnetic and solid-state, including general control relays, time relays, overcurrent relays, and other sub categories. Corresponding functional models can be selected according to specific scenarios, making it more versatile and expandable.

Core technical parameters

The 90.21 series relays cover multiple product types with certain differences in parameters. The following are the common core parameters and typical specifications of this series. In practical applications, the specific model's ABB official product manual should be followed:

1. Control circuit parameters: Rated control voltage (Uc) supports multiple specifications such as AC 24V/110V/230V, DC 12V/24V/48V, and is compatible with different control power systems; The rated current of the coil (electromagnetic type) is usually 50mA-300mA, the coil power is ≤ 5W, and the energy consumption is relatively low; Solid state relay control signals support DC 4V-32V (voltage signal) or 4mA-20mA (current signal), and are compatible with PLC, DCS and other control system outputs.

2. Output contact parameters: The contact forms are diverse, including 1 to 4 sets of normally open (NO), normally closed (NC), or conversion contacts (C/O), meeting the requirements of multi loop control; The rated working voltage (Ue) is AC 230V/400V or DC 24V/110V/220V, suitable for AC/DC loads; The rated working current (In) is 5A-30A (resistive load), with the general control type typically being 10A-16A and the power type reaching 20A-30A. It can directly drive solenoid valves, small motors, or control contactor coils; Contact electrical life (under rated load) ≥ 100000 times, mechanical life ≥ 1 million times.

3. Timing and protection parameters: The delay range of the time relay model is 0.01s-100min, with a delay accuracy of ≤± 5% (at room temperature), and supports modes such as power on delay, power-off delay, and cycle delay; The overcurrent relay model has an operating current range of 0.1A-50A, an operating accuracy of ≤± 10%, and can achieve overcurrent protection for motors or circuits; The action time of the universal relay is ≤ 10ms, and it responds quickly.

4. Environment and isolation parameters: The working environment temperature range is -40 ℃~+70 ℃, and some temperature resistant models can reach+85 ℃, suitable for extreme high and low temperature scenarios; The protection level of the shell is IP20 (board mounted) to IP65 (waterproof type), which meets the requirements of cabinet installation and outdoor temporary installation; The insulation resistance between the coil and the contact is ≥ 100M Ω, the insulation voltage (Ui) is ≥ 2.5kV AC, the anti electromagnetic interference (EMI) meets the IEC 61000-6-2 standard, and the anti surge capability reaches 2kV.

Structural characteristics and core advantages

1. Modular universal design

This series of relays adopts a standardized modular structure, with uniform installation dimensions for different functional models (control, time, overcurrent). It supports various installation methods such as 35mm DIN rail installation, PCB board installation, and panel installation. When replacing, there is no need to adjust the installation position, which improves maintenance efficiency; The wiring terminals adopt a uniform spacing crimping design, supporting 0.5mm ² -4mm ² hard/soft wire connections, with clear terminal identification (control end, power end, output end), reducing the risk of wiring errors; Some models support a plug-in structure, where the relay body is separated from the base and does not require rewiring during replacement, further simplifying the maintenance process.

2. Dual type drive, adapted to diverse needs

The series includes two types of drives: electromagnetic and solid-state. The electromagnetic relay adopts a low loss silicon steel core and optimized magnetic circuit design, with stable suction and low noise, suitable for frequent on-off scenarios, and low cost; Solid state relays have no mechanical contacts and use semiconductor switching elements, which have advantages such as arc free switching, long lifespan (unlimited mechanical lifespan), and fast response speed (≤ 1ms). They are suitable for explosion-proof, high-frequency switching (such as heating control), and noise free scenarios. Users can flexibly choose the type of driver based on load characteristics, switching frequency, and environmental requirements.

3. Industrial grade reliability and safety design

The shell is made of high-strength flame-retardant engineering plastic, with a flame-retardant rating of UL94 V-0, which can withstand instantaneous high temperatures and mechanical impacts, preventing safety hazards caused by short circuits; The electromagnetic relay contacts are made of silver nickel alloy or silver cadmium alloy, with low contact resistance (≤ 50m Ω), and are equipped with magnetic or grid arc extinguishing devices to quickly extinguish the breaking arc and extend the contact life; Solid state relays are equipped with overcurrent and over temperature protection circuits to prevent component burnout caused by load faults; The two ends of the coil (electromagnetic type) are equipped with freewheeling diodes to absorb reverse electromotive force and protect front-end control components (such as PLC output modules).

4. Status visualization and convenient debugging

All models are equipped with LED status indicator lights, which intuitively display power on/off, contact action or fault status. For example, the combination of "power light+action light" for electromagnetic relays and the combination of "control signal light+output status light" for solid-state relays allow operation and maintenance personnel to quickly determine the working status; The time relay model panel is equipped with a knob or dip switch, and the delay parameter adjustment is intuitive, without the need for professional tools to complete the setting; Some intelligent models support precise configuration and status monitoring of delay parameters through software connection debugging.

Applicable scenarios and typical applications

Based on its multi specification and multifunctional characteristics, the 90.21 series relays cover the entire industrial control scene, with typical applications including:

-Industrial automation control: Universal relays are used for signal amplification and isolation between PLCs, solenoid valves, and indicator lights to avoid direct loading of PLC output terminals; Time relays are used for coordinating process delays in production lines, such as the start stop interval of conveyor belts and preheating of heating equipment; Overcurrent relay is used for overcurrent protection of small motors, and is combined with contactors to achieve linkage between motor start stop and fault protection.

-In the field of power distribution: signal switching of auxiliary circuits in low-voltage distribution cabinets (such as voltage monitoring signal transmission), interlocking control of automatic backup power supply switching devices, and switching control of reactive power compensation capacitor groups; Solid state models are used in high-frequency switching capacitor switching scenarios to avoid arc damage.

-Rail transit and ship electrical: control circuit switching for lighting and ventilation systems inside train carriages, waterproof relays (IP65) for outdoor load control on ship deck equipment, overcurrent relays to protect ship motors from current surges under harsh working conditions; The wide temperature characteristics of this series can adapt to the high and low temperature operating environment of rail transit.

-In the field of buildings and people's livelihood: start stop control of central air conditioning fans and water pumps in building automation systems, power switching of access control and monitoring equipment in security systems; The door control circuit of household and commercial elevators achieves smooth start stop and safety interlocking of the door motor through relays.

-New energy and environmental protection equipment: auxiliary control circuit switching of photovoltaic inverters, balanced control signal transmission of battery packs in energy storage systems; Electromagnetic valves and actuator control for environmental protection equipment (such as dust collectors and desulfurization equipment), and solid-state relays are used for high-frequency pulse control of dust removal equipment.