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Siemens Relay LGB 21 550A27 - Burner Controls
SiemensBurner Controls

Siemens Relay LGB 21 550A27

Siemens LGB 21 550A27 is a burner control safety relay for gas or gas/oil burners up to 350 kW, supporting 1 or 2 stage operation with ionization probe or blue flame sensor flame detection. Ideal for industrial…

SKU 3G-CBM-05830

Brand
Siemens
Item
Relay LGB 21 550A27
Part Number
550A27
Category
Burner Controls
UNSPSC
40101833 — Boiler or heater igniter
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Local availability & support — Singapore

Local office
20 Woodlands Link #09-05, Singapore 738733
Phone
+65 8878 8355
Delivery
Same-day or next-business-day delivery within Singapore for in-stock items; 7–14 days for factory-order parts from Europe.
Payment
Invoicing in SGD. PayNow, bank transfer, and corporate PO accepted.
Ships to
Singapore

Technical Specifications

Siemens
Manufacturer Part Number
550A27
type
LGB 21 550A27
operation
intermittent
fuel types
gas or gas/oil
application
gas or gas/oil burner control safety relay
power rating
up to 350 kW
burner stages
1 or 2 stage
flame detection
ionization probe or blue flame sensor QRC1
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Siemens Products
3G Electric (S) Pte. Ltd. — Singapore

Product Description

Siemens LGB 21 550A27 is a burner control safety relay for gas or gas/oil burners up to 350 kW, supporting 1 or 2 stage operation with ionization probe or blue flame sensor flame detection. Ideal for industrial heating and combustion safety applications.

Frequently Asked Questions

What is the Siemens LGB 21 550A27 burner control used for?

The Siemens LGB 21 550A27 is a safety relay for gas or gas/oil burners up to 350 kW. It controls 1 or 2 stage operation with intermittent duty, using ionization probe or blue flame sensor QRC1 for flame detection. Common in industrial heating and combustion safety systems.

What are the specifications of the Siemens LGB 21 550A27?

The Siemens LGB 21 550A27 is an intermittent-operation burner control safety relay for gas or gas/oil burners up to 350 kW. It supports 1 or 2 stage operation and flame detection via ionization probe or blue flame sensor QRC1. It is designed for low to medium power burners with or without fan.

Where to buy Siemens LGB 21 550A27 in Singapore?

3G Electric supplies the Siemens LGB 21 550A27 burner control relay to Singapore. We handle sourcing, logistics, customs clearance, and delivery to your facility. Contact our team for pricing and lead time on this SKU.

How to install the Siemens LGB 21 550A27 burner control?

Installation must be done by qualified personnel only. Disconnect power before wiring near terminals. Use only manual force (≤10 N) on the reset button, never tools. Follow local safety regulations and verify wiring compliance. Do not reuse after a drop or impact.

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
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Siemens Products

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

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