Siemens 3su1400-1aa10-3ba0

By Abdullah Zahid
13 min read
Siemens 3SU1400-1AA10-3BA0 auxiliary contact module with 1 NO spring terminal for SIRIUS ACT 22mm pushbutton front plate mounting

Siemens 3SU1400-1AA10-3BA0 Contact Module with 1 Contact Element, 1 NO, Spring-Type Terminal, for Front Plate Mounting — Specifications, Wiring, and Selection Guide

Controls engineers and panel builders searching for the Siemens 3SU1400-1AA10-3BA0 are typically at the final stage of a purchase decision: they have identified the part number, they need to verify contact configuration, cavity compatibility, and current ratings, and they want to confirm availability before committing to a build. This is a single normally-open contact block with spring-loaded terminals, designed exclusively for front-plate mounting in SIRIUS ACT 22mm pushbutton control stations. It delivers 10,000,000 mechanical and electrical operating cycles and carries cULus, VDE, CCC, and KC certifications — one SKU that covers North American, European, Chinese, and Korean compliance requirements without alternative sourcing.

If you have already confirmed this is the right part, check current pricing and availability at LeadTime.ca — ships worldwide.

Who Should Buy the 3SU1400-1AA10-3BA0 — and Who Shouldn't

This contact module is the correct choice for engineers and panel builders who need to add a single normally-open signal output to an existing SIRIUS ACT 22mm control station without redesigning the control cabinet or adding an auxiliary relay. It is specifically right for your application if all of the following are true:

  • Your control station uses a SIRIUS ACT 22mm standard pushbutton or selector switch with an available front-plate cavity
  • You require exactly 1 NO (normally open) contact — not NC, not changeover
  • Your control voltage is within the module's rated range (24V AC/DC is the most common; verify against the operational current table for higher voltages)
  • Your wiring method supports spring-clamp terminal insertion — no screwdriver-tightened terminals
  • You can order in multiples of 5 — this module is sold in packs of 5; single-unit orders are not available from Siemens direct
  • You need multi-region certification coverage (cULus, VDE, CCC, KC) from a single part number

If you need a normally-closed contact instead of normally-open, the correct part is 3SU1400-1CC10-3BA0. If you need 2 contacts in one module, look at 3SU1400-1AA20-3BA0. If your application requires a positive-opening safety contact function, this series does not apply — select an appropriately rated safety contact block.

On this page:

What the 3SU1400-1AA10-3BA0 Actually Does in a Control System

The Siemens 3SU1400-1AA10-3BA0 is an auxiliary contact block — a discrete add-on that gives a 22mm SIRIUS ACT pushbutton or selector switch a signal output path to a PLC digital input, safety relay, or control contactor. The module clips into the front-plate cavity of a compatible control station and operates in parallel with the pushbutton mechanism. When the operator presses the button, the single NO contact closes and passes the control voltage signal downstream. When the button is released, the contact opens and the signal drops. No separate coil voltage, no standby current draw, and no additional terminal block real estate are required.

Spring-loaded terminals accept solid conductors from 0.25 to 1.5 mm² or stranded wire with bootlace ferrule from 0.25 to 0.75 mm². There are no screws to torque and no levers to actuate — insertion locks the conductor in place. This makes installation faster than screw-terminal equivalents and eliminates the risk of vibration-induced loosening in high-cycle machinery environments. The module measures 36 mm high, 9.8 mm wide, and 27.7 mm deep — a compact footprint that adds no width to the control station assembly.

The 10,000,000-cycle mechanical and electrical endurance rating is not a theoretical ceiling. At the maximum operating frequency of 3,600 cycles per hour, this module can run for approximately 2,777 continuous hours before reaching half its expected service life. On a standard 8-hour industrial shift at 250 working days per year, that translates to more than 50 years of normal use — making premature contact failure an unlikely cause of downtime in most applications.

Where This Module Sits in a Typical SIRIUS ACT System

The 3SU1400-1AA10-3BA0 occupies the contact-output layer of a SIRIUS ACT operator interface assembly — between the mechanical pushbutton and the control logic device receiving the signal. Understanding this position in the chain helps confirm whether this is the right module before ordering.

  • PLC or safety relay — receives the digital input signal from the contact module on a dedicated input channel
  • 24V DC supply or control bus — provides the voltage that passes through the closed NO contact when the button is pressed
  • SIRIUS ACT 22mm pushbutton or selector switch body — the mechanical actuator that drives the contact module's internal mechanism
  • 3SU1400-1AA10-3BA0 contact module — seated in the front-plate cavity, closes the NO contact when actuated, sends signal to PLC input
  • Spring-loaded wired conductors — carry the signal from the contact terminals to the PLC input terminal or control relay coil

Industries and Applications That Use This Contact Block

The most common deployment scenario is adding a status confirmation signal to an existing pushbutton without touching the control logic. A pump start button, for example, may already drive a contactor coil — adding the 3SU1400-1AA10-3BA0 to the front cavity simultaneously sends a separate signal to a PLC input for run-status logging or HMI display, with no rewiring of the existing contactor circuit.

In packaging and food and beverage processing machinery, this module appears frequently in two-hand control assemblies where multiple NO contacts from stacked contact blocks are wired in series to enforce simultaneous actuation. The 9.8 mm module width allows multiple contact blocks to be fitted to a single control station without exceeding panel cutout dimensions.

Panel retrofit projects are another strong use case. When a plant upgrades from hardwired mechanical interlocks to PLC-monitored inputs, installing a 3SU1400-1AA10-3BA0 in existing SIRIUS ACT buttons adds digital signal capability without replacing the entire control station assembly — reducing retrofit cost and downtime significantly compared to a full replacement.

Machinery safety circuits also use this module for gate and door interlock sensing, where the NO contact sends a pulse to a safety relay on door closure. Note that this module does not carry a positive-opening designation — for applications where IEC 60947-5-1 positive-opening is mandatory, a different contact block must be selected.

Application Typical Deployment
Machine start/stop operator panel Front-cavity NO contact sends run signal to PLC DI for status logging
Two-hand control safety function Two NO contacts wired in series; both buttons must be pressed simultaneously
Panel retrofit from mechanical interlock Added to existing SIRIUS ACT buttons to add PLC input without replacing control station
Pilot light + PLC signal expansion Button press drives lamp circuit AND sends separate NO contact signal to PLC input channel
Gate/door interlock sensing NO contact wired to safety relay input for machine shutdown validation
Material handling and conveyor control Deadman function using stacked NO contacts for operator presence confirmation

Specifications an Engineer Needs Before Ordering

Parameter Value
Contact Configuration 1 NO (normally open)
Thermal Current (Insulation Reference) 10 A at 500V insulation rating
AC-15 Rated Current at 230V 6 A
DC-13 Rated Current at 24V 3 A
Operating Temperature -25 to +70 °C
Insulation Voltage (Rated) 500V AC/DC
Surge Voltage Resistance 6 kV
IP Rating (Enclosure / Terminal) IP40 / IP20
Dimensions (H x W x D) 36 mm x 9.8 mm x 27.7 mm
Minimum Order Quantity 5 units (multiples of 5 only)

Full technical specifications are available on the product page at LeadTime.ca.

The operational current ratings vary significantly by voltage and load type. The table below covers the full rated range from the manufacturer datasheet:

Contact / Load Type 24V 48V 110V 230V 400V 500V
AC-12 (Motor loads) 10 A 10 A 10 A 8 A 8 A —
AC-15 (Inductive loads) 6 A 6 A 6 A 6 A 3 A 1.4 A
DC-12 10 A 5 A 2.5 A 1 A 0.3 A 0.3 A
DC-13 3 A 1.5 A 0.7 A 0.3 A 0.1 A 0.1 A

DC ratings drop steeply with voltage. If your application uses DC control voltage above 24V, verify the DC-12 or DC-13 rating at your actual circuit voltage before committing to this module. Exceeding rated current at a given voltage is a leading cause of contact welding and signal lockup.

3SU1400-1AA10-3BA0 vs. Related Variants: Which One Do You Actually Need?

Model Contact Configuration Terminal Type Key Difference Choose When
3SU1400-1AA10-3BA0 1 NO Spring-loaded Baseline single NO contact One NO contact needed; spring terminals required
3SU1400-1CC10-3BA0 1 NC Spring-loaded Normally closed instead of NO Control logic requires a break signal on button press
3SU1400-1AA20-3BA0 2 NO Spring-loaded Dual NO contacts in one module Two independent NO signals needed; limited cavity space
3SU1400-1AA11-3BA0 1 NO Check datasheet May differ in terminal or mounting detail Verify datasheet before substituting for 3BA0 variant

If your architecture uses a 22mm SIRIUS ACT front-cavity and requires a single normally-open contact with spring terminals, the 3SU1400-1AA10-3BA0 is the correct choice — check current availability at LeadTime.ca.

Expert Verdict: Honest Assessment for Controls Engineers

The 3SU1400-1AA10-3BA0 does exactly what a single-contact auxiliary block should do: it adds a reliable NO signal output to a SIRIUS ACT pushbutton without increasing cabinet footprint, without requiring a relay coil power supply, and without complicating the wiring layout. The 10,000,000-cycle endurance rating is not marketing language — at 3,600 cycles per hour maximum, this module will outlast the machine it is mounted in under normal shift-pattern usage. The spring-loaded terminals are a genuine advantage on high-vibration applications where screw terminals loosen over time. Multi-region certification from a single part number is particularly valuable for OEMs shipping panels to North America, Europe, China, and Korea — no variant hunting, no compliance re-work.

Where this module has real limits: it is not a safety contact block. Applications requiring IEC 60947-5-1 positive-opening contacts for mandatory safety functions must use a different product. The IP40 enclosure rating means it is suitable for control cabinet interiors and clean indoor factory environments — it is not rated for washdown, outdoor exposure, or splash zones. The DC current derating is significant: at 110V DC the DC-13 rating drops to 0.7 A, which eliminates this module from many higher-voltage DC control applications. And the minimum order of 5 units is a real constraint for single-unit emergency replacement scenarios — plan ahead and keep a 5-pack on the shelf.

From a procurement standpoint, this is a mature, stable part in an active product family. No obsolescence notice has been issued as of the research date for this article. Direct Siemens orders typically carry a 4–8 week lead time depending on region and production backlog. Stocked distributors can ship in-stock units in 2–5 business days. Unit pricing typically falls in the $5–15 USD range per module at standard volumes, with pack-of-5 and volume breaks available at 25–50 unit quantities — significantly cheaper than the $25–40 USD cost of an equivalent standalone auxiliary relay with terminal block and fused carrier. If this matches your system requirements, view current stock and pricing at LeadTime.ca.

For volume pricing or to confirm lead time before committing to a build, contact the LeadTime.ca team directly — we ship worldwide.

Wiring and Installation Overview

  • Strip 5–8 mm of insulation from conductor ends; for stranded wire, crimp a bootlace ferrule before insertion — spring terminals accept solid conductors 0.25–1.5 mm² and stranded with ferrule 0.25–0.75 mm²
  • Power down the control station and confirm de-energization with a voltmeter before inserting the module into the front-plate cavity
  • Align the module with the cavity slot and press firmly until the retention clip engages flush with the control station faceplate — the module face should sit flush, not recessed or protruding
  • Insert conductors into spring terminals with a single smooth motion to approximately 3–5 mm insertion depth; verify each conductor is secure by applying gentle hand pull — neither conductor should move
  • For DC-13 applications at 24V, observe terminal polarity markings; for AC-12 and AC-15 circuits, polarity is not relevant — verify your control voltage matches the rated current for your load type before final connection

Engineers requiring full wiring diagrams and detailed installation procedures should refer to the official Siemens datasheet (dated 18.03.2016) and SIRIUS ACT system manual available from the manufacturer.

Commissioning Checklist Before and After Installation

Before energizing, confirm these five points to avoid the most common commissioning failures with this module:

  • Cross-reference your control station part number against the SIRIUS ACT 22mm compatibility list — confirm the cavity is designated for front-mounted contact modules, not rear-mounted blocks
  • Verify PLC input channel voltage and current limits against the module's DC-13 or AC-15 rating at your control voltage — a mismatch at this stage causes contact welding or no-signal faults after power-up
  • On first power-up, press the pushbutton and confirm the assigned PLC input LED activates within 50 ms — hold pressed for 5 seconds and verify the signal remains stable with no chatter or toggling
  • Release the button and confirm the input immediately returns to the off state — a signal that remains high after button release indicates a stuck contact or wiring short
  • Repeat the press/release cycle at normal operating speed and document the result in your commissioning log with module model, control station ID, PLC input channel, and date

What Engineers Get Wrong When Ordering This Part

The following checklist covers the most common ordering and installation errors with the 3SU1400-1AA10-3BA0. Review every item before placing a purchase order:

  1. Confirm pushbutton/selector is SIRIUS ACT 22mm standard (not 30mm or other size)
  2. Verify cavity is designated for front-plate contact modules (not rear modules)
  3. Check contact count requirement: this module has exactly 1 contact, not 2 or more
  4. Confirm contact type is NO (normally open); not NC or changeover
  5. Validate terminal type is spring-loaded; wiring method must support spring-clamp insertion
  6. Ensure control voltage and current do not exceed AC-12 or AC-15 rated values at target voltage
  7. Confirm minimum order: units must be ordered in quantities of 5 or multiples thereof
  8. Cross-reference datasheet date (18.03.2016) with any system changes or obsolescence notices since deployment

If you have worked through this checklist and confirmed this is the right part, check stock and place your order at LeadTime.ca — or contact us to confirm lead time and volume pricing before your build date.

Frequently Asked Questions

Can I order a single unit of the 3SU1400-1AA10-3BA0, or do I have to buy a pack of 5?

Siemens packages and sells this module in quantities of 5 — minimum order is 5 units, and orders must be in multiples of 5 (5, 10, 15, 20, and so on). Some stocking distributors may be able to sell individual units from open stock, but this varies by supplier and region. If you need only one spare, ordering a 5-pack and shelving the remaining four for future maintenance is the most practical approach given the $5–15 USD per-unit cost.

What is the difference between 3SU1400-1AA10-3BA0 and 3SU1400-1CC10-3BA0?

The 3SU1400-1AA10-3BA0 provides 1 normally-open (NO) contact — the circuit is open at rest and closes when the button is pressed. The 3SU1400-1CC10-3BA0 provides 1 normally-closed (NC) contact — the circuit is closed at rest and opens when the button is pressed. Both use spring-loaded terminals and fit the same SIRIUS ACT 22mm front-plate cavity. The choice depends entirely on whether your control logic requires a make signal or a break signal on actuation.

What is the DC-13 current rating at 24V DC, and why does it matter?

The DC-13 rating at 24V DC is 3 A. DC-13 covers switching of inductive DC loads such as PLC output coils, solenoid valves, and relay coils powered by 24V DC — the most common control voltage in modern automation systems. If your load draws more than 3 A at 24V DC, this module's contact rating is exceeded and premature contact wear or welding will result. Verify your actual load current against this value before wiring.

Does the 3SU1400-1AA10-3BA0 require an external fuse or circuit breaker?

Yes. This module does not contain internal circuit protection. An external fuse or MCB (miniature circuit breaker) sized for the maximum operating current at your intended control voltage must be installed upstream. For a 24V DC control circuit running at up to 10 A (DC-12), a 10 A upstream protective device is appropriate. For higher voltages such as 230V AC, refer to the AC-15 operational current table and size protection accordingly.

Is the 3SU1400-1AA10-3BA0 suitable for safety functions requiring positive-opening contacts?

No. This series does not carry a positive-opening designation as defined by IEC 60947-5-1. Applications where positive-opening contact operation is a mandatory safety requirement — such as emergency stop circuits or safety gate monitoring — must use contact blocks specifically rated and certified for that function. Using the 3SU1400-1AA10-3BA0 in a mandatory positive-opening application is a non-conforming design.

What certifications does the 3SU1400-1AA10-3BA0 carry, and which markets does it cover?

The module carries cULus (North America), VDE (Germany and EU), CCC (China), and KC (Korea) certifications, plus EU Declaration of Conformity and UK Declaration of Conformity. This single part number covers the compliance requirements for control panel installations in all four major industrial markets without needing to source a regional variant — a practical advantage for OEMs building panels for global deployment.

Why Order from LeadTime.ca

  • Global shipping — LeadTime.ca ships the 3SU1400-1AA10-3BA0 worldwide; no regional sourcing restrictions
  • Hard-to-find and short-lead-time stock — access to stocked inventory that ships in days, not the 4–8 weeks typical of direct manufacturer orders
  • Volume pricing available — contact the team for breaks at 25, 50, and higher unit quantities; relevant for multi-station panel builds
  • Fast quote response — procurement specialists can confirm availability and lead time before you commit to a project schedule
  • Bundled sourcing — order contact modules alongside SIRIUS ACT pushbutton bodies, pilot lights, and other control station accessories in a single transaction

At-a-Glance Summary

  • Contact configuration: 1 NO (normally open), spring-loaded terminals, front-plate cavity mounting
  • Compatible with SIRIUS ACT 22mm standard pushbuttons and selector switches only — not 30mm or non-Siemens formats
  • DC-13 rated current at 24V DC: 3 A; AC-15 rated current at 230V AC: 6 A — verify against your load before ordering
  • Mechanical and electrical endurance: 10,000,000 cycles typical; maximum operating frequency 3,600 cycles per hour
  • Operating temperature range: -25 to +70 °C; storage: -40 to +80 °C
  • Insulation rated at 500V AC/DC; surge voltage resistance 6 kV; pollution degree 3
  • Physical dimensions: 36 mm H x 9.8 mm W x 27.7 mm D
  • Certifications: cULus, VDE, CCC, KC, EU and UK Declaration of Conformity — single SKU for global deployment
  • Minimum order: 5 units; must be ordered in multiples of 5
  • Unit cost typically $5–15 USD depending on volume; 40–60% less expensive than equivalent auxiliary relay plus terminal block assembly
  • Stocked distributor lead time: 2–5 business days; direct Siemens lead time: 4–8 weeks