Siemens 3SB3400-0C Screw Terminal Contact Block

3SB3400-0C: SIRIUS 3SB3 series, передняя панель mounted single contact block, 1Северная Каролина (1 Нормально закрытый), screw terminal type. Designed for 22mm кнопки / selector switches, Positive Opening safety contact.

Статус продукта: Снято с производства (PM490). Original manufacturer supply stopped. Recommended replacement model: 3SU1400-1AA10-1CA0 (SIRIUS ACT series)

Core Technical Data

Выбор & Matching Guidelines

1. Cross reference of contact blocks in the same series

3SB3400-0B: 1НЕТ (Single Normally Open)

3SB3400-0C: 1Северная Каролина (Одинарный нормально закрытый, эта модель)

3SB3400-0A: 1НО+1НЗ (1 Changeover)

3SB3400-0D: 2НЕТ; 3SB3400-0E: 2Северная Каролина

2. Stacking Rule: One contact block occupies one mounting slot; Макс. 3 contact blocks for non-illuminated pushbuttons
3. Positive Opening Feature: This NC contact is a safety contact, suitable for E-Stop circuits and meets positive opening requirements for safety loops. Priority selection for emergency stop applications.

Сценарии применения

22mm pushbuttons, rotary switches and emergency stop signal collection in control cabinets

ПЛК digital input circuits, safety E-Stop loops, interlock circuits

Guard interlocks, equipment limit detection, fault alarm signals

Руководство по устранению неполадок

1. Low-level signal (5V/1mA): Contact oxidation shall be checked first. Although low-level reliability is specified, aged contacts may suffer poor contact.
2. Схема безопасности: Positive opening NC contact must be used. Ordinary contacts are prohibited as substitutes. During maintenance, manually actuate pushbutton and verify reliable contact opening.
3. Электропроводка: Control tightening torque of screw terminals; loose connections cause signal jitter. Terminals IP20, metal dust prevention required inside cabinet terminal area.

Replacement Model Description

Direct OEM replacement: 3SU1400-1AA10-1CA0 (SIRIUS ACT,1Северная Каролина, винтовой терминал, positive opening, 22mm pushbutton system).

Bases of old & new series cannot be interchanged. Full assembly replacement (actuator + база + контакты) is required when switching to 3SU1.

1. 3SB3 Pushbutton Assembly Selection Examples (Based on 3SB3400-0C 1NC Contact Block)

Core rule: 3SB3 adopts modular assembly: Привод + Base Holder + Contact Block. Макс. 3 contact blocks for non-illuminated pushbuttons; max.2 contact blocks for illuminated pushbuttons. Each contact block occupies one mounting slot.

Contact block list recap

3SB3400-0B:1НЕТ

3SB3400-0C:1Северная Каролина (эта модель, positive opening safety contact)

3SB3400-0A:1НО+1НЗ

3SB3400-0D:2НЕТ; 3SB3400-0E:2Северная Каролина

Example1: Mushroom Head Emergency Stop (Safety Circuit, Most Common for 3SB3400-0C)

Цель: Equipment emergency stop, safety circuit positive opening NC

Привод:3SB3000-1HA20 (Red mushroom head, twist reset)

Base holder:3SB3901-0AC (3-position holder)

Контакт: 3SB3400-0C (1NC positive opening)

Complete factory pre-assembled part number:3SB3203-1HA20-0AC0 (factory pre-fitted with 1NC, no separate contact ordering required). Redundant safety circuit can add a second 3SB3400-0C for dual NC.

Example2: Red Momentary Pushbutton (Fault Acknowledge)

Цель:Сброс неисправности, PLC DI acquisition

Привод:3SB3000-0AA21 (Red flat momentary button)

Holder:3SB3901-0AC (3-position holder)

Contact combination:3SB3400-0B (1НЕТ) + 3SB3400-0C (1Северная Каролина)

Функция:NO for DI signal; NC for circuit fault verification

Example3: 2-position Selector Switch (0-я)

Цель:Local/Remote mode switchover

Switch actuator:3SB3000-2CA11 (2-position latching selector switch)

Holder:3SB3901-0AC

Контакт:3SB3400-0B (NO for I position) + 3SB3400-0C (NC for 0 позиция)

Example4: Illuminated Green Start Pushbutton

Ограничение: Max.2 contact blocks for illuminated pushbuttons

Привод:3SB3000-4AA31 (Green illuminated flat pushbutton)

Lamp holder:3SB3401-1A (LED lamp holder)

Контакт:3SB3400-0B (1NO for start) + 3SB3400-0C (1НЗ для блокировки)

1. Replacement List from Old 3SB3 to New SIRIUS ACT 3SU1

⚠️Important: 3SB3 and 3SU1 bases/contact blocks are completely non-interchangeable. Contacts cannot be replaced alone; full assembly replacement (actuator + база + контакты) is mandatory.

Original contact block 3SB3400-0C (1NC screw terminal, positive opening)

→ Corresponding contact: 3SU1400-1AA10-1CA0 (1Северная Каролина, винтовой терминал, positive opening)

III. Сборка & Engineering Guidelines

1. Contact stacking sequence: Mount safety NC contact (3SB3400-0C) closest to panel side for best mechanical synchronization. Recommended for emergency stop safety circuits.
2. Крутящий момент: Screw terminal tightening torque 0.8~1.2 N·m. Loose connections lead to DI signal fluctuation; loose terminals strictly prohibited for safety circuits.
3. Low-level signal: PLC passive DI (5V/1mA). Use OEM contacts preferably. Aged contacts tend to oxidize, NC circuits more prone to intermittent conduction.
4. Panel cutout: Standard Φ22mm round hole; round 3SB3 panel thickness: 1～6 mm; square 3SB3 panel thickness: 1～4 mm.
5. Migration Notes During Model Replacement
6. Cabinet cutout unchanged, both Φ22mm, but front bezel profile differs. Deburr if old cutout edge corroded.
7. Terminal position changes after replacement, redraw terminal diagram to avoid wiring misconnection.
8. Схема безопасности: New 3SU1 1NC contact also features positive opening, complies with EN 60947-5-1 and can directly replace original 3SB3400-0C for emergency stop applications.
9. Spare part strategy: 3SB3 series discontinued by OEM, only stock parts available on market. New projects adopt 3SU1 directly.

Сименс 3SB3400-0C Mounting Dimensions

This model is a single contact block (1Северная Каролина) belonging to 3SB3 series modular 22mm pushbutton components. The contact block has no separate cutout, clipped onto 3SB3 holder (3SB3901-0AC). Complete pushbutton panel cutout Φ22mm.

Contact Block Physical Dimensions (мм)

Ширина: 10 мм (standard width of single contact block, each block occupies 10mm during stacking)

Высота: 36.5 мм

Глубина: 20 мм (from holder surface backward including screw terminals)

Single contact blocks (3SB3400-0B / 0С) share identical dimensions. Double contact blocks (3SB3400-0A/0D/0E) width =20mm.

Complete Pushbutton Assembly Dimensions (Holder + Contact Blocks)

1. Вырез в панели: Φ22 mm (standard 22mm pushbutton round hole)

Round pushbutton panel thickness: 1～6 mm

Square pushbutton panel thickness: 1～4 mm

2. 3-position holder 3SB3901-0AC: Макс. 3 single contact blocks stacked, total stacking width=3×10=30 mm
3. Cabinet rear depth:

1 контактный блок: ~42 mm (panel rear face to terminal end)

Fully loaded with 3 contact blocks: ~42 mm (глубина не изменилась, only lateral width increases)

Mounting Spacing Requirements

Center-to-center minimum distance between adjacent 22mm pushbuttons: 50мм (round type); мин. 50mm for square 3SB3 pushbuttons

Reserved rear cabinet space: ≥45mm for wiring and terminal tightening

Dimension Comparison with Replacement Model 3SU1400-1AA10-1CA0 (3SU1 Contact Block)

Body dimension: W10mm × H36.5mm × D20mm, similar body size

⚠️Holder structure differs and cannot be directly interchanged. Panel cutout still Φ22mm but rear mounting profile is different.

Engineering Drawing Notes

1. Contact block is clip-on type, no fixing screws; slide and clip into holder rail.
2. Terminal screws protrude rearward. Reserve ≥45mm depth for cabinet layout.
3. Stacking sequence: Mount safety NC contact (3SB3400-0C) nearest to panel.