How to Select an Interface Relay for PLC Outputs
A step-by-step guide to matching PLC output type, coil voltage and current, contact rating, and socket style when selecting an interface relay.
- Part number
- SR2B121FU
- UL
- CSA
Zelio LogicSchneider Electric SR2B121FU Zelio Logic SR2 12 I/O 100-240 V AC with Display 4 Relay Outputs Logic Module
Zelio Logic SR2 compact smart relay, 8 DI, 4 relay DO, 100-240 V AC supply, with clock, built-in display.
Description
About the SR2B121FU
About the SR2B121FU
The Schneider Electric SR2B121FU is a Zelio Logic SR2 compact smart relay with 8 discrete inputs and 4 relay outputs rated 8 A each, powered from 100-240 V AC. Its built-in LCD display and navigation buttons, with a real-time clock, let you program, monitor, and diagnose simple automation tasks directly on the unit.
Certifications & Standards
- GL
- GOST
- UL
- CSA
- C-tick
- IEC 61000-4-4
- IEC 60068-2-27 Ea
- IEC 61000-4-5
- IEC 61000-4-11
- IEC 61000-4-12
- IEC 61000-4-3
- IEC 60068-2-6 Fc
- IEC 61000-4-2
- IEC 61000-4-6
Selection Notes
The SR2B121FU is the 100-240 V AC member of the 12-I/O Zelio Logic SR2 compact range, with a built-in real-time clock for time-based control such as scheduled lighting or pump cycling. Where fewer or more I/O points are needed, the 10-I/O and 20-I/O SR2 variants in the same family cover the range without changing the programming environment.
Specification
Full specification
Main 2
| Range of Product | Zelio Logic |
|---|---|
| Product or Component Type | Compact smart relay |
Complementary 38
| Local display | With |
|---|---|
| Number or control scheme lines | 0…240 ladder, 0…500 FBD |
| Cycle time | 6…90 ms |
| Backup time | 10 years 77 °F (25 °C) |
| Clock drift | 12 min/year 32…131 °F (0…55 °C), 6 s/month 77 °F (25 °C) |
| Checks | Program memory on each power up |
| [Us] rated supply voltage | 100...240 V AC |
| Supply voltage limits | 85…264 V |
| Supply frequency | 50/60 Hz |
| Maximum supply current | 30 mA 240 V without extension), 80 mA 100 V without extension) |
| Power consumption in VA | 7 VA without extension |
| Isolation voltage | 1780 V |
| Protection Type | Against inversion of terminals (control instructions not executed) |
| Discrete input number | 8 |
| Discrete input voltage | 100...240 V AC |
| Discrete input current | 0.6 mA |
| Discrete input frequency | 47...53 Hz, 57...63 Hz |
| Voltage state 1 guaranteed | >= 79 V discrete input |
| Voltage state 0 guaranteed | <= 40 V discrete input |
| Current state 1 guaranteed | >= 0.17 mA discrete input) |
| Current state 0 guaranteed | <= 0.5 mA discrete input) |
| Analogue input number | 0 |
| Input impedance | 350 kOhm discrete input |
| Number of Outputs | 4 relay |
| Output voltage limits | 5...30 V DC relay output), 24...250 V AC |
| Contacts type and composition | NO relay output |
| Output thermal current | 8 A for all 4 outputs relay output |
| Electrical durability | AC-12 500000 cycles 230 V, 1.5 A relay output IEC 60947-5-1, AC-15 500000 cycles 230 V, 0.9 A relay output IEC 60947-5-1, DC-12 500000 cycles 24 V, 1.5 A relay output IEC 60947-5-1, DC-13 500000 cycles 24 V, 0.6 A relay output IEC 60947-5-1 |
| Switching capacity in mA | >= 10 mA 12 V relay output) |
| Operating rate in Hz | 0.1 Hz at Ie)relay output, 10 Hz no load)relay output |
| Mechanical durability | 10000000 cycles relay output |
| [Uimp] rated impulse withstand voltage | 4 kV EN/IEC 60947-1 and EN/IEC 60664-1 |
| Clock | With |
| Response time | 50 ms ladder from state 0 to state 1)discrete input, 50 ms ladder from state 1 to state 0)discrete input, 50...255 ms FBD from state 0 to state 1)discrete input, 50...255 ms FBD from state 1 to state 0)discrete input, 10 ms from state 0 to state 1)relay output, 5 ms from state 1 to state 0)relay output |
| Connections - terminals | Screw terminals, 1 x 0.2...1 x 2.5 mm² 25 AWG...14 AWG) semi-solid, Screw terminals, 1 x 0.2...1 x 2.5 mm² 25 AWG...14 AWG) solid, Screw terminals, 1 x 0.25...1 x 2.5 mm² 24 AWG...14 AWG) flexible with cable end, Screw terminals, 2 x 0.2...2 x 1.5 mm² 24 AWG...16 AWG) solid, Screw terminals, 2 x 0.25...2 x 0.75 mm² 24 AWG...18 AWG) flexible with cable end |
| Tightening torque | 4.4 lbf.in (0.5 N.m) |
| Overvoltage category | III conforming to IEC 60664-1 |
| Net Weight | 0.55 lb(US) (0.25 kg) |
Environment 12
| Immunity to microbreaks | 10 ms |
|---|---|
| Product Certifications | GL, GOST, UL, CSA, C-tick |
| Standards | IEC 61000-4-4 level 3, IEC 60068-2-27 Ea, IEC 61000-4-5, IEC 61000-4-11, IEC 61000-4-12, IEC 61000-4-3, IEC 60068-2-6 Fc, IEC 61000-4-2 level 3, IEC 61000-4-6 level 3 |
| IP degree of protection | IP20 IEC 60529 terminal block), IP40 IEC 60529 front panel) |
| Environmental characteristic | EMC directive conforming to IEC 61000-6-2, EMC directive conforming to IEC 61000-6-3, EMC directive conforming to IEC 61000-6-4, EMC directive conforming to IEC 61131-2 zone B, Low voltage directive conforming to IEC 61131-2 |
| Disturbance radiated/conducted | Class B EN 55022-11 group 1 |
| Pollution degree | 2 IEC 61131-2 |
| Ambient air temperature for operation | -4…104 °F (-20…40 °C) in non-ventilated enclosure IEC 60068-2-1 and IEC 60068-2-2, -4…131 °F (-20…55 °C) IEC 60068-2-1 and IEC 60068-2-2 |
| Ambient Air Temperature for Storage | -40…158 °F (-40…70 °C) |
| Operating altitude | 6561.68 ft (2000 m) |
| Maximum altitude transport | 10000 ft (3048 m) |
| Relative Humidity | 95 % without condensation or dripping water |
Show all 65 specifications ↓ Show less ↑13 more values in Identification, Contractual warranty, Logistics.
Identification 7
| Part number | SR2B121FU |
|---|---|
| Brand | Schneider Electric |
| Condition | New, factory sealed |
| Source | Schneider Electric and its authorised distributors |
| Warranty | Manufacturer warranty |
| Lifecycle status | Active, in production |
| EAN | 3389110547641 |
Contractual warranty 1
| Warranty (in months) | 18 |
|---|
Logistics 5
| Country of origin | FR |
|---|---|
| Shipping weight | 0.25 kg |
| Ships from | Türkiye |
| Dispatch | — |
| Stock | On request |
Source: manufacturer data · Last verified: 30 Oct 2026
Documents
Documents for SR2B121FU
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Ask us for the datasheet
Certifications
Certifications and standards
- UL
- CSA
- IEC 61000-4-4 level 3
- IEC 60068-2-27 Ea
- IEC 61000-4-5
- IEC 61000-4-11
- IEC 61000-4-12
- IEC 61000-4-3
- IEC 60068-2-6 Fc
- IEC 61000-4-2 level 3
- IEC 61000-4-6 level 3
Quick answers
Questions about the SR2B121FU
Which supply voltage is SR2B121FU rated for?
The rated operational voltage of SR2B121FU is 100–240 V AC.
What is the HS code of SR2B121FU for customs?
The tariff (HS) code on file for SR2B121FU is 853710.
What is the EAN of SR2B121FU?
The EAN (GTIN) of SR2B121FU is 3389110547641.
Where does SR2B121FU ship from, and how fast?
SR2B121FU ships from Türkiye. Shipping calculated at checkout · import duties and taxes paid on arrival.
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Series
Schneider Electric Zelio Logic
- Brand
- Schneider Electric
- Series
- Zelio Logic
