What is the difference between RL, RLE, RLI, and RLF breakers?

All four are variants of the Siemens Type RL low voltage power circuit breaker. The RL (standard) is available in all frame sizes from 800A to 5000A with interrupting ratings from 30 to 100 kA. The RLE (economical) offers higher interrupting capacity per frame (42–100 kA) and is available in frames 800A through 4000A. The RLI (integrally fused) is available only at 800A with 85 kA interrupting capacity and includes integral current-limiting fuses. The RLF (fully rated) provides 200 kA interrupting at all frame sizes but is available only in drawout construction. All four variants use the same Static Trip III trip unit and share a common accessory platform.

How do I read a Siemens RL catalog number?

An RL catalog number is a 12+ character code following the prefix "RL". Each position encodes a specific configuration: Position 1 = Connection (A=Drawout, B=Stationary), Position 2 = Interrupting Type (S=Standard, E=Economical, I=Integrally Fused, F=Fully Rated), Position 3 = Frame Size (0=800A through 5=5000A), Position 4 = Operation (M=Manual, E=Electric), Positions 5–6 = Tripping Sensor (e.g., AG=800/.5), Position 7 = Current Limiting Fuses, Position 8 = Control Voltage, Position 9 = System Wiring, Positions 10–11 = Trip Unit Code, Position 12 = Additional Auxiliary Contacts. Optional suffix codes after a dash indicate factory-installed accessories such as bell alarms, dual shunt trips, and undervoltage devices.

What is the Siemens Static Trip III trip unit?

The Static Trip III is an electronic trip unit that provides adjustable overcurrent protection for all RL series breakers. It supports up to 8 protection functions: T (Thermal/Long-Time), S (Short-Time), I (Instantaneous), G (Ground Fault), Z (Zone Selective Interlocking), C (Communications), N (Neutral protection), and P (Power Metering). There are 53 distinct Static Trip III configuration codes (04 through 56), each offering a different combination of these features. The AC Pro II (codes 58, 59) is an aftermarket retrofit trip unit manufactured by Utility Relay Company (URC), not original Siemens factory production. The physical hardware comes in variants: III (base), IIIC (communications), IIICP (communications + power metering), and IIICPX (full feature set). All trip units require a matching rating plug sized to the breaker sensor.

What replaced the Siemens RL breaker?

Siemens discontinued the RL product line and closed its Wendell, NC manufacturing facility. For existing RL switchgear, nothing needs to "replace" the RL — Voyten Electric purchased all remaining RL inventory (breakers, Static Trip III units, drawings, tooling, and every renewal part) directly from Siemens Wendell, making Voyten the New Surplus authorized source for genuine RL breakers and parts. Existing installations are fully supported with original Siemens-sourced equipment, with no need to modify or replace the switchgear. Siemens current-production air circuit breakers are not drop-in compatible with RL cells — they use a different frame geometry, trip unit platform, and cell interface — so any retrofit would require all-new switchgear. That is why facilities with installed RL equipment source genuine RL replacements and renewal parts from Voyten.

Are RL and LA breaker parts interchangeable across production eras?

Yes. The Siemens Type RL was manufactured exclusively under the Siemens name throughout its production life. Unlike SPB breakers (which transitioned across Westinghouse, Cutler-Hammer, and Eaton branding), the RL maintained a single manufacturer identity. All RL parts are interchangeable regardless of production date. The companion Type LA air circuit breaker (600A–3000A) shares the same Siemens origin and parts compatibility across its full production run.

Technical Reference Guide

Siemens Type RL Low Voltage Power Circuit BreakerComplete Technical Reference — Models, Specifications & Parts Guide

Everything you need to know about the Siemens Type RL low voltage power circuit breaker (LVPCB) — from model identification and catalog number structure to trip unit selection, sensor configurations, and parts sourcing.

What Is the RL Breaker?

The Siemens Type RL is a low voltage power circuit breaker (LVPCB) in drawout construction, designed for power distribution systems rated up to 635V AC. Frame sizes range from 800A to 5000A, with interrupting capacities from 30 kA to 200 kA RMS symmetrical depending on variant.

The RL uses the Static Trip III electronic trip unit for adjustable LSIG (Long-time, Short-time, Instantaneous, Ground fault) overcurrent protection. Four breaker variants serve different application requirements: the RL (standard), RLE (economical with higher interrupting per frame), RLI (integrally fused), and RLF (fully rated at 200 kA). The companion Type LA air circuit breaker covers 600A–3000A ratings within the same product family.

Siemens discontinued the RL product line and closed the Wendell, NC manufacturing facility. In 2023, Voyten Electric acquired all remaining RL and LA inventory directly from Siemens — the complete stock of breakers, Static Trip III units, renewal parts, drawings, and tooling — establishing Voyten as the New Surplus authorized source for the RL product line.

RL Model Lineup

Model	Designation	Interrupting (635V)	Frame Range	Notes
RL	Standard	30–100 kA	800–5000A	All 6 frame sizes; drawout or stationary
RLE	Economical	42–100 kA	800–4000A	Higher interrupting per frame than RL
RLI	Integrally Fused	85 kA	800A only	Integral current-limiting fuses
RLF	Fully Rated	200 kA	800–5000A	Drawout only; highest interrupting
LA	Air Circuit Breaker	—	600–3000A	Companion product line

Frame codes: 0 = 800A, 1 = 1600A, 2 = 2000A, 3 = 3200A, 4 = 4000A, 5 = 5000A.

Renewal Parts Categories

Voyten Electric stocks the following RL renewal part categories for immediate shipment:

Anti-Pump Y Relay

Auxiliary Switch

Bell Alarm Switch

Blown Fuse Trip Assembly

Breaker Assemblies

Close Solenoid

Communications Options

Contacts (800–2000A)

Contacts (3200–5000A)

Integrally Fused Breakers

Key Interlock & Fuse Carriage

Motor Operator

Open Fuse Indicator

Open Fuse Sensor

Operator Mechanism

Secondary Disconnect

Shunt Trip

Static Trip III Unit

Tapped Sensor

Trigger Fuse Assembly

Tripping Transformer

Undervoltage Trip Device

Interrupting & Short-Time Ratings

All ratings are in kA RMS symmetrical per UL 1066 / IEEE C37.50. The values below reflect ratings at maximum design voltage per Siemens SG-3061 / SG-3068. Always consult the breaker nameplate for voltage-specific ratings in your application.

Model	Frame	Interrupting (kA)	Short-Time (kA)
RL Standard
RL	800A	30	30
RL	1600A	65	50
RL	2000A	65	65
RL	3200A	65	65
RL	4000A	85	85
RL	5000A	100	100
RLE Economical
RLE	800A	42	42
RLE	1600A	65	65
RLE	2000A	85	85
RLE	3200A	100	85
RLE	4000A	100	85
RLI Integrally Fused
RLI	800A	85	65
RLF Fully Rated
RLF	All (800–5000A)	200	200

Sources: Siemens SG-3061 / SG-3068. Consult breaker nameplate for application-specific voltage ratings.

Identify Your RL Breaker

Every RL breaker is identified by a structured catalog (edge) number that encodes its exact frame size, interrupting type, operation, tripping sensor, current-limiting fuses, control voltage, system wiring, Static Trip III code, and accessories. Reading it correctly is what guarantees an exact-match replacement — so rather than risk a mis-decode on an emergency part, send us the number and our team will decode it for you, fast.

Decode a catalog number

Send us the full RL catalog/edge number and our team decodes the exact frame, trip unit, sensor, fuse, and accessory configuration.

Contact for Decode

Read the nameplate

Not sure which RL variant you have? Send a photo of the breaker nameplate and we’ll identify it for an exact-match replacement.

Find the right renewal parts

Match the exact frame, Static Trip III, tripping sensor, and accessories to in-stock New Surplus inventory.

Shop RLBreakers.com

Emergency identification

Breaker down right now? Our team identifies and sources the correct RL part 24/7 to get you back online fast.

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Static Trip III Trip Unit

All RL breakers use the Siemens Static Trip III electronic trip unit for adjustable overcurrent protection. The trip unit mounts to the breaker front and connects via a rating plug sized to the breaker's sensor. There are 53 distinct configuration codes (positions 10–11 of the catalog number), each offering a different combination of protection functions.

Code	Feature	Function
T	Thermal	Long-time delay — adjustable pickup and time band
S	Short-Time	Short-time delay — I²t or flat response
I	Instantaneous	Instantaneous pickup — fixed or adjustable
G	Ground Fault	Ground fault — adjustable pickup and delay
Z	Zone Selective	Zone selective interlocking (upstream/downstream coordination)
C	Communications	Remote communications interface
N	Neutral	Neutral current protection
P	Power Metering	Onboard power quality monitoring

Common Trip Unit Configurations

04 T (thermal only)

06 T, S, I

07 T, I, G

09 T, S, I, G, Z

13 T, S, I, G, Z, C

15 T, S, I, G, Z, C, N

46 T, S, I, G, Z, C, N, P (full suite)

58 AC Pro II (aftermarket retrofit by Utility Relay Co.)

53 Static Trip III codes (04–56) plus 2 AC Pro II codes (58, 59). Code XX = non-automatic (no trip unit). The physical trip unit hardware varies by feature set: Static Trip III (base),IIIC (with communications), IIICP (communications + power metering), and IIICPX (full feature set). Higher codes require the corresponding hardware variant.

Rating Plug Requirement

All Static Trip III and AC Pro II trip units require a matching rating plug sized to the breaker's sensor. The rating plug sets the long-time pickup range and must match the installed CT sensor. When replacing a trip unit, always verify the rating plug compatibility.

Product History

Unlike the SPB breaker (which transitioned across Westinghouse, Cutler-Hammer, and Eaton branding), the Type RL was manufactured exclusively under the Siemens name throughout its entire production life at the Wendell, NC facility.

Siemens Type RL

Original & sole manufacturer

Production: Wendell, NC facility

After Siemens discontinued the RL and closed the Wendell facility, Voyten Electric acquired the complete remaining inventory. All RL parts are interchangeable regardless of production date. The companion Type LA air circuit breaker (600A–3000A) shares the same Siemens origin and parts compatibility across its full production run.

Technical Documentation

The following Siemens instruction leaflets and catalogs cover the RL product line. All are available as free PDF downloads from Voyten Manuals.

Document	Number	Content
RL Installation Manual	SGIM-3068	Complete installation, operation, and maintenance instructions
RL Installation Manual (Extended)	SGIM-3068E	Extended edition with additional wiring details
RL Renewal Parts Catalog	SG-3068	Complete renewal parts list with exploded diagrams
Static Trip III Info & Instruction Guide	SG-3118	Trip unit configuration, settings, and calibration
Static Trip III Guide (Updated)	SG-3118-01	Revised edition of SG-3118
Wiring Diagrams & Control Power	SGIM-3068D	System wiring diagrams (FIG 1A through FIG 20B)
Static Trip II Reference	SG3098-01	Legacy trip unit documentation (predecessor to Static Trip III)

View all Siemens RL manuals →

Need RL Parts or Technical Support?

Voyten Electric is the New Surplus authorized source for the complete Siemens RL product line. New-surplus breakers, Static Trip III units, sensors, and every renewal part — tested, in stock, and ready to ship.

1-800-458-4001 Request a Quote

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