We ship worldwide — Singapore, Australia, Malaysia, Indonesia, Philippines, India, Middle East & more

3G Electric
RFQ CartGet a QuoteSign inSign up
Siemens 3RR22421FW30 3-Phase Current Monitoring Relay - Current Monitoring Relays
SiemensCurrent Monitoring Relays

Siemens 3RR22421FW30 3-Phase Current Monitoring Relay

The SIEMENS 3-Phase Current Monitoring Relay is a current monitoring relay designed for three-phase systems. It includes over and under current monitoring capabilities, with a current range of 4 A to 40 A. This…

SKU 3G-OTH-28783

Brand
Siemens
Item
3RR22421FW30 3-Phase Current Monitoring Relay
Category
Current Monitoring Relays
Available to Order
Trade pricing by quote — replies within 24h
Qty
WhatsApp an engineerMessage via Telegram
No account needed — your quote request goes straight to our engineers. A free account lets you track quotes and re-order faster.
Worldwide Shipping
Air & sea freight
Datasheet on Request
Technical specs
1-Day Quote
Replies within 24h

Local availability & support

Delivery
Worldwide DHL shipping from Singapore; 7–14 business days door-to-door for most destinations.
Payment
Invoicing in USD. Bank transfer (SWIFT) and corporate PO accepted.

Technical Specifications

Siemens
Manufacturer Part Number
3RR22421FW30
Type
4 A – 40 A
Phase
3-Phase
Includes
Over and Under Current Monitoring
Product Type
Current Monitoring Relay
Phase Configuration
3-Phase

Technical Documents

No technical documents available for this product.
Request documentation →
Not sure this is the right part? Get a recommendation.

Need installation or engineering help?

Installation, commissioning, maintenance plans, system design, and bundled product + service quotes — one team handles the full scope.
Talk to an engineer

Ask a question

Siemens Products
3G Electric (S) Pte. Ltd. — Singapore

Product Description

The SIEMENS 3-Phase Current Monitoring Relay is a current monitoring relay designed for three-phase systems. It includes over and under current monitoring capabilities, with a current range of 4 A to 40 A. This device is identified by manufacturer part number 3RR22421FW30.

Frequently Asked Questions

What is the SIEMENS 3RR22421FW30 current monitoring relay used for?

The SIEMENS 3RR22421FW30 is a 3-phase current monitoring relay used to protect motors and industrial equipment by detecting overcurrent and undercurrent conditions. It is commonly applied in manufacturing, HVAC, and pumping systems to prevent damage from phase imbalance or load faults.

What are the specifications of the SIEMENS 3RR22421FW30?

The SIEMENS 3RR22421FW30 is a 3-phase current monitoring relay with a current range of 4 A to 40 A. It includes both over and under current monitoring. The manufacturer part number is 3RR22421FW30, and it is designed for three-phase systems.

Where to buy the SIEMENS 3RR22421FW30 worldwide?

You can source the SIEMENS 3RR22421FW30 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.

How to install the SIEMENS 3RR22421FW30 current monitoring relay?

Install the SIEMENS 3RR22421FW30 by mounting it on a DIN rail, connecting the three-phase supply through the relay's current transformers, and wiring the output contacts to your control circuit. Always follow the manufacturer's manual for proper settings and safety isolation.

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.

You might also need

Burners & Combustion →Pumps & Compressors →Spare Parts →All Products →

Compatible alternatives & equivalents

Cross-referenced by specification & description
This Siemens IEC magnetic contactor is a non-reversing device with 4 poles and 2 normally open and 2 normally closed contacts. Rated for 25 A with a 240V AC coil, it is used for switching motors, lighting, and heating loads in industrial control panels and automation systems
Siemens
This Siemens IEC magnetic contactor is a non-reversing device with 4 poles and 2 normally open and 2 normally closed contacts. Rated for 25 A with a 240V AC coil, it is used for switching motors, lighting, and heating loads in industrial control panels and automation systems
Non-reversing IEC contactor with three poles and three normally open contacts. Rated 12 A with a 240V AC coil. No integrated surge suppression. Used for switching electrical loads in motor control and automation applications such as conveyors, pumps, compressors, and HVAC systems
Siemens
Non-reversing IEC contactor with three poles and three normally open contacts. Rated 12 A with a 240V AC coil. No integrated surge suppression. Used for switching electrical loads in motor control and automation applications such as conveyors, pumps, compressors, and HVAC systems
This non-reversing IEC contactor from Siemens has 3 poles and 3 normally open contacts, rated for 115 A with a 120V AC coil. It does not include integrated surge suppression. Typical applications include switching three-phase motors and other inductive loads in industrial automation and HVAC systems
Siemens
This non-reversing IEC contactor from Siemens has 3 poles and 3 normally open contacts, rated for 115 A with a 120V AC coil. It does not include integrated surge suppression. Typical applications include switching three-phase motors and other inductive loads in industrial automation and HVAC systems
This Siemens non-reversing IEC contactor features 3 poles and 3 normally open (NO) contacts, rated at 9 A with a 120V AC coil. It is designed for switching and controlling electrical loads such as motors, lighting, and other inductive loads in industrial automation and HVAC systems. No integrated surge suppression is included
Siemens
This Siemens non-reversing IEC contactor features 3 poles and 3 normally open (NO) contacts, rated at 9 A with a 120V AC coil. It is designed for switching and controlling electrical loads such as motors, lighting, and other inductive loads in industrial automation and HVAC systems. No integrated surge suppression is included
Non-reversing IEC magnetic contactor with 3 poles and 3 normally open (NO) contacts. Rated 32 A with a 120V AC coil. Suitable for switching motors, lighting, and other industrial loads in control panels, conveyors, and HVAC systems. No integrated surge suppression
Siemens
Non-reversing IEC magnetic contactor with 3 poles and 3 normally open (NO) contacts. Rated 32 A with a 120V AC coil. Suitable for switching motors, lighting, and other industrial loads in control panels, conveyors, and HVAC systems. No integrated surge suppression
This Siemens IEC magnetic contactor is a non-reversing, 4-pole device rated at 25 A with a 120V AC coil. It features 2 normally open and 2 normally closed auxiliary contacts. Suitable for switching motors, lighting, and other loads in industrial control panels and power distribution systems
Siemens
This Siemens IEC magnetic contactor is a non-reversing, 4-pole device rated at 25 A with a 120V AC coil. It features 2 normally open and 2 normally closed auxiliary contacts. Suitable for switching motors, lighting, and other loads in industrial control panels and power distribution systems

More from Siemens

View all Siemens parts →
2-phase current monitoring relay with over and under current detection. Adjustable range from 4 A to 40 A. Used in industrial control panels to monitor motor loads, pumps, and conveyors for fault conditions
Siemens
2-phase current monitoring relay with over and under current detection. Adjustable range from 4 A to 40 A. Used in industrial control panels to monitor motor loads, pumps, and conveyors for fault conditions
This 2-phase current monitoring relay from Siemens is designed to detect overcurrent and undercurrent conditions within a 1.6 A to 16 A range. It is typically used in industrial control panels to protect motors and equipment from electrical faults, ensuring operational safety in applications such as manufacturing, HVAC, and pumping systems
Siemens
This 2-phase current monitoring relay from Siemens is designed to detect overcurrent and undercurrent conditions within a 1.6 A to 16 A range. It is typically used in industrial control panels to protect motors and equipment from electrical faults, ensuring operational safety in applications such as manufacturing, HVAC, and pumping systems
Three-phase current monitoring relay with over and under current detection. Adjustable current range from 1.6 A to 16 A. Used to monitor load conditions in motor and industrial equipment applications
Siemens
Three-phase current monitoring relay with over and under current detection. Adjustable current range from 1.6 A to 16 A. Used to monitor load conditions in motor and industrial equipment applications