Main Components of a PLC System: Complete Guide for Engineers
Master PLC system components: CPU, power supply, I/O modules, communication interfaces, and software with sizing formulas and selection tips. Shop at Stoklink.
Siemens SITOP SEL1200 selectivity module, 6EP4437-7FB00-3DX0, 8x1-5A adjustable, 24V/40A input, IP20.
The Siemens SITOP SEL1200 6EP4437-7FB00-3DX0 is an 8-channel selectivity module for 24 V DC systems, taking a 40 A input and distributing it across eight outputs each adjustable from 1 to 5 A, with 98% efficiency and a monitoring interface for status signaling. It isolates an overloaded branch in as little as 30 ms without dropping the other seven channels.
The 8-channel output count doubles the branch density of a 4-channel selectivity module in the same 40 A input class, which reduces the number of modules needed in a cabinet with many small 24 V loads. The graduated overcurrent response - 30 ms at 2x setpoint down to 5 s at the setpoint itself - trips fast on a hard short but tolerates brief inrush from contactors or solenoids without nuisance tripping. The floating signal contact or pulse/pause status output lets a SIMATIC function block read individual channel status instead of a single common alarm.
Suited for cabinets with many small independent 24 V DC loads - distributed I/O stations, sensor branches, valve islands - where per-channel status feedback into the PLC is worth the extra wiring versus a common alarm contact.
| product brand name | SITOP |
|---|---|
| product type designation | SEL1200 |
| product designation | SITOP Selectivity module |
| type of current supply | selectivity module, 8 x 1 ... 5 A com. sign. contact or diagnostics monitor |
| type of the power supply network | Controlled DC voltage |
|---|---|
| supply voltage at DC rated value | 24 V |
| input voltage at DC | 20.4 ... 30 V |
| overvoltage overload capability | 35 V |
| input current at rated input voltage 24 V rated value | 40 A |
| voltage curve at output | controlled DC voltage |
|---|---|
| formula for output voltage | Vin - approx. 0.2 V |
| relative overall tolerance of the voltage note | In accordance with the supplying input voltage |
| number of outputs | 8 |
| output current up to 60 °C per output rated value | 5 A; +60 ... +70 °C: Derating 2%/K |
| adjustable current response value current of the current-dependent overload release | 1 ... 5 A |
| type of response value setting | via potentiometer |
| response delay maximum | 5 s |
| product feature parallel switching of outputs | Yes |
| type of outputs connection | switch-on of all outputs after power-up of the supply voltage > 20 V, delay time of 25 ms, 200 ms, 500 ms, or "load-optimized" via DIP switch configurable for sequential switch-on |
| Part number | 6EP4437-7FB00-3DX0 |
|---|---|
| Type designation | SEL1200 |
| Brand | Siemens |
| Condition | New, factory sealed |
| Source | Siemens and its authorised distributors |
| Warranty | Manufacturer warranty |
| Lifecycle status | Active, in production |
| EAN | 4025515155423 |
| ETIM class | EC001440 |
| eCl@ss | 27371802 |
| efficiency in percent | 98 % |
|---|---|
| power loss [W] at rated output voltage for rated value of the output current typical | 10 W |
| switching characteristic: of the excess current | Iout > 2.0 x set value, switch-off after approx. 30 ms, Iout > 1.8 x set value, switch-off after approx. 0.1 s, Iout > 1.5 x set value, switch-off after approx. 1 s, Iout > 1.0 x set value, switch-off after approx. 5 s |
|---|---|
| switching characteristic: of the immediate switch-off | Iout > set value and Vin < 20 V, switch-off after approx. 8 ms |
| design of the reset device/resetting mechanism | via sensor per output |
| remote reset function protection and monitoring | non-isolated 24 V input (signal level "high" at > 15 V) |
| fuse protection type at input | 10 A per output (not accessible) |
| display version for normal operation | Three-color LED per output: green LED for "Output switched through"; yellow LED for "Output switched off manually"; red LED for "Output switched off due to overcurrent" |
| design of the switching contact for signaling function | Floating common signal contact or status signal output (pulse/pause signal that can be evaluated via SIMATIC function block) |
| galvanic isolation between input and output at switch-off | No |
|---|---|
| standard for safety | according to EN 62368-1 |
| operating resource protection class | Class III |
| protection class IP | IP20 |
| standard: for emitted interference | EN 61000-6-3 |
| standard: for interference immunity | EN 61000-6-2 |
| certificate of suitability: CE marking | Yes |
|---|---|
| certificate of suitability: UL approval | Yes; UL-Recognized (UL 2367) File E328600; cULus-Listed (UL 508, CSA C22.2 No. 107.1) File E197259 |
| certificate of suitability: UKCA marking | Yes |
| certificate of suitability: EAC approval | Yes |
| type of certification: CB-certificate | Yes |
| certificate of suitability: IECEx | No |
|---|---|
| certificate of suitability: ATEX | No |
| shipbuilding approval | Yes |
|---|---|
| Marine classification association: Det Norske Veritas (DNV) | Yes |
| Environmental Product Declaration | Yes |
|---|---|
| global warming potential [CO2 eq]: total | 287.5 kg |
| global warming potential [CO2 eq]: during manufacturing | 13.1 kg |
| global warming potential [CO2 eq]: during operation | 274 kg |
| global warming potential [CO2 eq]: after end of life | 0.3 kg |
| Siemens eco profile (SEP) | Siemens EcoTech |
| ambient temperature: during operation | -40 ... +70 °C; with natural convection |
|---|---|
| ambient temperature: during transport | -40 ... +85 °C |
| ambient temperature: during storage | -40 ... +85 °C |
| environmental category according to IEC 60721 | Climate class 3K3, 5 ... 95% no condensation |
| type of electrical connection | Push-in |
|---|---|
| at input | 24V1, 24V2: push-in for 0.5 ... 16 mm2; 0V1, 0V2: push-in for 0.5 ... 4 mm2 |
| at output | Output 1 ... 8: push-in for 0.5 ... 4 mm2 |
| for auxiliary contacts | RST: push-in for 0.2 ... 1.5 mm2 |
| for signaling contact | 13, 14: push-in for 0.2 ... 1.5 mm2 |
| width × height × depth of the enclosure | 45 × 135 × 125 mm |
|---|---|
| installation width × mounting height | 45 mm × 225 mm |
| required spacing: top | 45 mm |
| required spacing: bottom | 45 mm |
| required spacing: left | 0 mm |
| required spacing: right | 0 mm |
| fastening method | Snaps onto DIN rail EN 60715 35x7.5/15 |
| DIN-rail mounting | Yes |
| S7 rail mounting | No |
| wall mounting | No |
| housing can be lined up | Yes |
| identification link | Yes; acc. to IEC 61406-1:2022 |
|---|
| other information | Specifications at rated input voltage and ambient temperature +25 °C (unless otherwise specified) |
|---|
| Net weight | 0.3 kg |
|---|---|
| Country of origin | Romania |
| Shipping weight | 0.8 kg |
| Ships from | Türkiye |
| Dispatch | 16 Nov |
| Stock | Low stock |
Source: manufacturer data · Last verified: 01 Nov 2026
The rated current of SEL1200 is 40 A.
The rated operational voltage of SEL1200 is 24 V AC.
The rated motor power of SEL1200 is 10 W kW.
The tariff (HS) code on file for SEL1200 is 85363010.
The EAN (GTIN) of SEL1200 is 4025515155423.
SEL1200 ships from Türkiye. Shipping calculated at checkout · import duties and taxes paid on arrival. Stock items are dispatched within 1–2 business days.
Master PLC system components: CPU, power supply, I/O modules, communication interfaces, and software with sizing formulas and selection tips. Shop at Stoklink.