Schneider XB2-BA31C Metal Series Pushbutton

Model Explanation

XB2-BA31C (Complete ordering model; suffix “C” cannot be omitted)

XB2: Harmony XB2, 22 mm metal pushbutton series

BA: Flush head, spring return pushbutton

3: Green

1: 1 Normally Open contact (1NO)

Component breakdown: ZB2BA3C (pushbutton head) + ZB2BZ101C (1NO contact block)

2. Main Technical Specifications

3. Typical Applications

Start pushbutton for industrial control cabinets: motor startup, equipment operation triggering, jog control circuits.

Matching reference: Red stop pushbutton XB2-BA42C (1NC)

4. Common Flush Pushbuttons of the Same Series

XB2-BA11C: White, 1NO

XB2-BA21C: Black, 1NO

XB2-BA31C: Green, 1NO (this model)

XB2-BA41C: Red, 1NO; XB2-BA42C: Red, 1NC

XB2-BA51C: Yellow, 1NO

XB2-BA61C: Blue, 1NO

5. Installation Notes
6. Applicable panel thickness: 1～6 mm
7. Recommended tightening torque for mounting nut: 0.8 N·m
8. For additional contacts, stack ZB2-BE101 (NO) / ZB2-BE102 (NC) contact modules
9. This model has no built-in indicator light; for illuminated green start pushbutton, select XB2BW33C series

Complete Installation Procedure for Schneider XB2-BA31C (XB2-BA31)

Component composition: ZB2BA3C (green flush pushbutton head) + ZB2BZ101C (1NO contact block)

Preconditions & Tools

1. Panel Requirements

Standard cutout: Φ22 mm, deburred cutout without sharp edges

Applicable panel thickness: 1～6 mm

Minimum centre spacing between adjacent pushbuttons: ≥ 30 mm

2. Required Tools

Flat screwdriver (PH1), wire stripper; torque screwdriver recommended

3. Official Standard Torque Values

Pushbutton mounting nut: 0.8 N·m (Do NOT over-tighten)

Terminal screws: 0.5～0.8 N·m

4. Cable Specification

Recommended 0.5～1.5 mm² stranded copper control cable, stripping length 7～10 mm

Step-by-Step Standard Installation Sequence

⚠️ First step for all electrical work: Cut off main power supply of control cabinet, implement lockout & tagout!

Step 1: Parts Inventory & Visual Inspection

Check complete set after unpacking:

1. Green pushbutton operating head ZB2BA3C (equipped with sealing gasket to ensure IP65 protection)
2. Metal locking nut
3. Contact block ZB2BZ101C (1NO)

Verify sealing gasket intact and plastic latches free from cracks.

Step 2: Insert Pushbutton Head into Control Panel (Install from FRONT of panel)

1. Fit sealing gasket properly onto the rear shoulder of pushbutton head (gasket cannot be omitted or twisted)
2. Insert pushbutton head into Φ22 mm cutout from outer (front) side of panel
3. Threaded shank extends out from rear panel; keep pushbutton head closely attached to panel surface without tilt

Step 3: Mount locking nut to secure pushbutton head

1. Screw metal locking nut onto threaded shank from rear side, hand-tight until touching panel
2. Tighten evenly with tool, maintain torque at 0.8 N·m

✅ Acceptance criteria: Pushbutton free of wobble, smooth pressing without jamming

❌ Do not apply excessive force! Over-tightening will crack sealing gasket, cause pushbutton seizure and void IP65 protection.

Step 4: Snap-fit contact block (Most frequent assembly error point)

1. Two elastic latches on contact block front side align with slots on rear of pushbutton head
2. Push contact block horizontally and straightly; two audible “click” sounds confirm full engagement of both latches

❗ Do not pry diagonally or force press violently; broken latches require replacement of contact block

✅ Removal method: Pry both side latches gently with flat screwdriver and pull contact block backward

Step 5: Wiring Operation (XB2-BA31, 1NO contact)

Terminal marking printed on contact block:

Terminals 3, 4 = Normally Open (NO): Open circuit at rest, closed when pressed

1. Strip cable insulation, prevent loose copper strands and burrs
2. Insert conductor into terminal hole; ensure insulation is not clamped under screw
3. Tighten terminal screw clockwise (torque 0.5～0.8 N·m)
4. Light traction test on cable to confirm no looseness; exposed copper strands may lead to short circuit risk

Step 6: Mechanical test before power-on (Mandatory procedure)

1. Press pushbutton repeatedly: smooth operation, instant automatic rebound after release, no sticking or abnormal noise
2. Visually confirm contact block latches fully locked to avoid detachment under vibration
3. Check sealing gasket fits panel evenly without gaps (critical for dust & water resistance)

Step 7: Continuity test before energization

Use multimeter continuity mode to test terminals 3 and 4:

Rest state: Open circuit (infinite resistance)

Push and hold pushbutton: Conductive (resistance close to 0 Ω)

Only proceed to switch on power after passing test.

Typical Wiring Reference (Standard Start Circuit)

Control power supply → Terminal 3

Terminal 4 → Contactor coil / PLC digital input

Push button pressed → Terminals 3-4 conduct, start signal triggered

Common Installation Mistakes & Warnings

1. Missing / distorted sealing gasket → Loss of IP65 rating; dust and moisture ingress leads to contact oxidation and poor conductivity
2. Excessive torque on mounting nut → Internal mechanism compressed, pushbutton fails to rebound
3. Diagonally forcing contact block → Plastic latches fracture; contact block may fall off during equipment operation
4. Over-stripped cable and loose copper strands → Risk of short circuit between adjacent terminals
5. Panel cutout larger than Φ22.2 mm → Pushbutton wobbles and sealing fails
6. Do not mount contact block first then pass pushbutton through panel! Correct sequence: Secure pushbutton head to panel first, then attach contact block

Disassembly Procedure (For contact maintenance & replacement)

Cut off power → Pry two latches of contact block with flat screwdriver → Pull contact block backward;

To remove complete pushbutton: Unscrew rear locking nut, extract pushbutton head from panel front.

Operating Principle of Schneider XB2-BA31C (XB2-BA31)

Component composition: ZB2BA3C (green spring return pushbutton head) + ZB2BZ101C (1NO contact block)

It is a mechanical momentary pushbutton without indicator light.

1. Mechanical Operating Principle
2. Initial state (Unpressed)

Built-in compression spring pushes operating head outward and maintains extended position. Internal moving contact is separated from stationary contact.

2. Actuation state (Push down button)

External force depresses green pushbutton head → Internal pushrod travels backward → Drives movable contact bridge inside contact block to displace

Contact bridge connects two stationary contacts simultaneously, terminals 3 and 4 (NO) closed.

3. Release state (Automatic return)

When external pressure disappears, built-in spring rebounds and resets pushrod; contact bridge retracts, contacts separate again, circuit between 3 and 4 opens.

Characteristic: Momentary type (jog operation), non-latching; conductive only while being pressed.

2. Electrical Principle (XB2-BA31: 1NO Normally Open)

Terminal marking on contact block: 3, 4 = Normally Open (NO)

Static status: Circuit open between 3 and 4 (infinite resistance)

Push button: Circuit closed between 3 and 4

Upon release: Circuit restores open state instantly

Contacts are passive mechanical dry contacts:

No built-in power supply; only switches on/off external control circuits. Compatible with low-voltage AC/DC control loops (contactor coils, PLC DI inputs, relay circuits).

3. Brief Internal Structure Breakdown
4. Pushbutton housing + return spring
5. Transmission pushrod (transmit pressing force)
6. Contact block: Fixed stationary contacts + movable conductive contact bridge
7. Screw wiring terminals

Force transmission sequence:

Manual pressing → Pushbutton head → Pushrod compresses spring → Contact bridge displacement → Contacts closed

Release button → Spring extends and resets → Contact bridge retreats → Contacts open

4. Key Characteristics
5. No built-in indicator lamp, no lighting power supply required; distinguish from illuminated model XB2BW33C.
6. Pure physical mechanical contact switching without electronic components, strong anti-interference performance.
7. IP65 protection relies on front sealing gasket to prevent water vapour and dust entering contact cavity.
8. Typical Application Logic (Motor Start Circuit Example)

Control live L → Terminal 3

Terminal 4 → Contactor KM coil → Neutral N

When XB2-BA31C is pressed → KM coil energizes, contactor pulls in;

Pushbutton circuit opens upon release, continuous operation maintained by self-locking via auxiliary NO contact of contactor.

Common Misunderstandings

❌ Not a latching pushbutton: Circuit opens after release, cannot sustain conduction status

❌ Not suitable as limit switch under continuous compression; accelerates spring fatigue

❌ Contacts only serve control circuits, cannot directly drive high-power loads