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SIEMENS 1-Phase Current Monitoring Relay: Current Monitoring Relay, 2-Phase Phase - Current Monitoring Relays
SiemensCurrent Monitoring Relays

SIEMENS 1-Phase Current Monitoring Relay: Current Monitoring Relay, 2-Phase Phase

The SIEMENS Current Monitoring Relay (MPN 3RR21421AW30) is a 2-phase relay that monitors for over and under current conditions. It operates within a 4 A to 40 A range, providing essential protection for industrial…

SKU 3G-OTH-28768

Brand
Siemens
Item
1-Phase Current Monitoring Relay: Current Monitoring Relay, 2-Phase Phase
Category
Current Monitoring Relays
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Technical Specifications

Siemens
Manufacturer Part Number
3RR21421AW30
Type
4 A – 40 A
Phase
2-Phase
Includes
Over and Under Current Monitoring
Product Type
Current Monitoring Relay
Phase Configuration
2-Phase
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Siemens Products
3G Electric (S) Pte. Ltd. — Singapore

Product Description

The SIEMENS Current Monitoring Relay (MPN 3RR21421AW30) is a 2-phase relay that monitors for over and under current conditions. It operates within a 4 A to 40 A range, providing essential protection for industrial equipment.

Frequently Asked Questions

What is the SIEMENS 3RR21421AW30 current monitoring relay used for?

The SIEMENS 3RR21421AW30 current monitoring relay protects industrial equipment by detecting over and under current conditions in 2-phase systems. It is commonly used in motor control centers, pumps, and conveyors to prevent damage from electrical faults, ensuring operational safety and reducing downtime.

What are the specifications of the SIEMENS 3RR21421AW30 current monitoring relay?

The SIEMENS 3RR21421AW30 is a 2-phase current monitoring relay with a 4 A to 40 A range. It includes both over and under current monitoring functions. The manufacturer part number is 3RR21421AW30, and it is designed for industrial applications requiring reliable phase and current protection.

Where to buy the SIEMENS 3RR21421AW30 current monitoring relay worldwide?

You can source the SIEMENS 3RR21421AW30 current monitoring relay through 3G Electric, a global industrial equipment distributor. We handle full logistics, customs clearance, and delivery to worldwide destinations. Contact us for availability and lead time; we supply genuine Siemens components for industrial protection needs.

How to install the SIEMENS 3RR21421AW30 current monitoring relay?

Install the SIEMENS 3RR21421AW30 relay by mounting it on a DIN rail in a control panel. Connect the 2-phase supply through the relay's current transformers, and wire the output contacts to your alarm or trip circuit. Always follow Siemens wiring diagrams and de-energize the system before installation to ensure safety.

Used in

Common applications for Siemens
District cooling plants — LME73 + RWF55 for condenser-water modulation
Inflight catering and food-processing steam boilers — LMG22 with SQN90 air-fuel cross-damper
Hospital steam-plant redundancy — LME41 with QRA2 UV flame detection for dual-fuel boilers
Semiconductor fab process heat — LME23 and SKP55 gas valves on hot-oil heater skids
Container-terminal reefer-deck heating — LMG22 retrofit onto legacy burner racks

Siemens Products

3G Electric supplies Siemens current monitoring relays. We supply genuine products with in-stock availability on common SKUs, technical documentation, commissioning support, and warranty service — worldwide.

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