A push button contact block is the rear switching module that converts operator movement into an electrical contact change. Select it by required contact state, number of circuits, operator compatibility, mounting system, voltage and load category, terminal method, switching frequency, environment, and failure behavior. “1NO” or “1NC” describes the normal mechanical state, not the complete machine function. The front operator, holder, contact block, enclosure, wiring, and control logic must be treated as one assembly and verified from the exact product documentation.
선택 규칙: 장치, 액추에이터, 접점, 외함, 배선, 제어 로직, 사용자, 그리고 기계 움직임을 하나의 시스템으로 취급하십시오. 제품 예시는 형태만을 보여주며, 최종 적합성은 정확한 주문 코드에 대한 최신 문서와 완성된 장비에서의 검증을 통해 얻어져야 합니다.
작동 원리
Pressing the operator transfers motion through a collar or holder to one or more modular contact blocks. Normally open contacts close after operation; normally closed contacts open. Momentary operators return when released, while maintained operators remain in their selected state until reset by their mechanism. Contact blocks may look interchangeable but differ in mounting keys, depth, travel, terminal layout, ratings, and direct-opening claims.
선정 기준 한눈에 보기
| 의사결정 영역 | 확인해야 할 사항 | 공학적 이유 |
|---|---|---|
| Contact function | Define each NO and NC circuit from the required normal and operated states | Labels must match the machine state diagram. |
| Operator compatibility | Use the approved operator, holder, and block family | Similar dimensions do not prove mechanical compatibility. |
| Number and stacking | Check allowed block positions and rear depth | Extra blocks add space, force, and wiring complexity. |
| Electrical load | Verify voltage, current, AC/DC type, load category, inrush, and minimum load | Headline current alone is incomplete. |
| Terminal method | Choose screw, tab, clamp, solder, or connector for the wiring process | Termination affects inspection, torque, and serviceability. |
| Positive opening needs | Use only documented devices in a validated safety architecture | An NC marking alone does not establish safety behavior. |
| 환경 | Protect rear blocks from dust, moisture, conductive debris, and chemicals | Front-panel sealing may not cover the rear assembly. |
| Maintenance | Provide identification, access, test points, and replacement control | A correct block can still be wired or replaced incorrectly. |
이 표는 의도적으로 정성적인 것입니다. 수치적 한계, 정격, 토크, 힘, 이동 거리, 환경 관련 주장, 내구성은 현재 데이터시트에서 가져와 애플리케이션 조건 하에서 평가해야 합니다.
상세 선발 절차
Contact function
확인할 사항: Define each NO and NC circuit from the required normal and operated states. Labels must match the machine state diagram. The requirement should be written in the project specification and traced to the exact model drawing or datasheet. Review worst-case tolerance, wear, contamination, maintenance access, and foreseeable misuse. If the available documentation does not define the boundary, keep the point open for supplier confirmation and sample testing rather than substituting an assumption.
Operator compatibility
확인할 사항: Use the approved operator, holder, and block family. Similar dimensions do not prove mechanical compatibility. The requirement should be written in the project specification and traced to the exact model drawing or datasheet. Review worst-case tolerance, wear, contamination, maintenance access, and foreseeable misuse. If the available documentation does not define the boundary, keep the point open for supplier confirmation and sample testing rather than substituting an assumption.
Number and stacking
확인할 사항: Check allowed block positions and rear depth. Extra blocks add space, force, and wiring complexity. The requirement should be written in the project specification and traced to the exact model drawing or datasheet. Review worst-case tolerance, wear, contamination, maintenance access, and foreseeable misuse. If the available documentation does not define the boundary, keep the point open for supplier confirmation and sample testing rather than substituting an assumption.
Electrical load
확인할 사항: Verify voltage, current, AC/DC type, load category, inrush, and minimum load. Headline current alone is incomplete. The requirement should be written in the project specification and traced to the exact model drawing or datasheet. Review worst-case tolerance, wear, contamination, maintenance access, and foreseeable misuse. If the available documentation does not define the boundary, keep the point open for supplier confirmation and sample testing rather than substituting an assumption.
Terminal method
확인할 사항: Choose screw, tab, clamp, solder, or connector for the wiring process. Termination affects inspection, torque, and serviceability. The requirement should be written in the project specification and traced to the exact model drawing or datasheet. Review worst-case tolerance, wear, contamination, maintenance access, and foreseeable misuse. If the available documentation does not define the boundary, keep the point open for supplier confirmation and sample testing rather than substituting an assumption.
Positive opening needs
확인할 사항: Use only documented devices in a validated safety architecture. An NC marking alone does not establish safety behavior. The requirement should be written in the project specification and traced to the exact model drawing or datasheet. Review worst-case tolerance, wear, contamination, maintenance access, and foreseeable misuse. If the available documentation does not define the boundary, keep the point open for supplier confirmation and sample testing rather than substituting an assumption.
환경
확인할 사항: Protect rear blocks from dust, moisture, conductive debris, and chemicals. Front-panel sealing may not cover the rear assembly. The requirement should be written in the project specification and traced to the exact model drawing or datasheet. Review worst-case tolerance, wear, contamination, maintenance access, and foreseeable misuse. If the available documentation does not define the boundary, keep the point open for supplier confirmation and sample testing rather than substituting an assumption.
Maintenance
확인할 사항: Provide identification, access, test points, and replacement control. A correct block can still be wired or replaced incorrectly. The requirement should be written in the project specification and traced to the exact model drawing or datasheet. Review worst-case tolerance, wear, contamination, maintenance access, and foreseeable misuse. If the available documentation does not define the boundary, keep the point open for supplier confirmation and sample testing rather than substituting an assumption.
지원서 검토
- Start and stop command stations. Record the expected command, response, release behavior, abnormal condition, and acceptance evidence for the assembled machine.
- Mode and reset controls. Record the expected command, response, release behavior, abnormal condition, and acceptance evidence for the assembled machine.
- Dual-circuit command arrangements. Record the expected command, response, release behavior, abnormal condition, and acceptance evidence for the assembled machine.
- Illuminated operators with separate lamp circuits. Record the expected command, response, release behavior, abnormal condition, and acceptance evidence for the assembled machine.
- Maintenance-friendly modular panels. Record the expected command, response, release behavior, abnormal condition, and acceptance evidence for the assembled machine.
모든 애플리케이션에 대해 시동, 정상 작동, 종료, 전원 손실, 전원 복구, 유지보수 모드, 부품 교체, 그리고 위험성 평가로 식별된 결함을 포함해야 합니다. 일반적인 제어 스위치는 완전한 안전 기능으로 간주되어서는 안 됩니다.
시운전 체크리스트
- 요건을 동결하세요. 의도된 동작, 정상 상태, 공급, 부하, 운동, 환경 및 사용자를 명시하십시오.
- 주문 코드를 일치시키세요. 납품된 부품을 승인된 도면, 접점도, 구동기, 단자 형식 및 부속품과 비교하십시오.
- 설치를 검사하십시오. Check alignment, fasteners, rear clearance, cable routing, strain relief, protection of live parts, and access for service.
- Test every state. Verify operation and release at tolerance extremes, expected speeds, loads, gloves, contamination, and environmental conditions.
- Test abnormal conditions. Include disconnected conductors, blocked or damaged mechanisms, power loss, contamination, and other credible faults.
- Record the result. Save model, revision, test method, observations, acceptance criteria, date, and approver.
Common mistakes
- Confusing normal state with desired machine state. Prevent this by assigning the check to a drawing, datasheet, wiring record, or commissioning test with a named acceptance criterion.
- Mixing contact blocks from another product family. Prevent this by assigning the check to a drawing, datasheet, wiring record, or commissioning test with a named acceptance criterion.
- Ignoring rear-panel clearance. Prevent this by assigning the check to a drawing, datasheet, wiring record, or commissioning test with a named acceptance criterion.
- Switching an unsuitable high-inrush load directly. Prevent this by assigning the check to a drawing, datasheet, wiring record, or commissioning test with a named acceptance criterion.
- Assuming front IP protection covers the terminals. Prevent this by assigning the check to a drawing, datasheet, wiring record, or commissioning test with a named acceptance criterion.
What to include in an RFQ
Provide the application, target market, applicable standards, machine function, supply and load, control interface, contact logic, mechanical drawing, motion path, panel dimensions, cable method, environment, operating frequency, quantity, documentation needs, and sample-validation plan. Ask the supplier to identify assumptions and exceptions. ONPOW offers relevant products in its application-specific product family and the broader industrial control product range.
Related ONPOW guides
Authoritative references
- IEC 60947-5-1 control-circuit devices
- IEC 60529 degrees of protection provided by enclosures
- OSHA machine guarding requirements
- OSHA electrical safety requirements
Educational video
Push Buttons Explained: NO vs NC Types, Symbols, and Wiring Diagrams by Automatedo provides general background. Project decisions still require the applicable standards and product documentation.
Frequently asked questions
What does 1NO mean?
One normally open contact circuit is open in the defined normal mechanical state and closes when operated.
Can NO and NC blocks be stacked?
Only within the operator family rules, allowed positions, force, depth, and ratings stated by the manufacturer.
Is an NC block suitable for emergency stop?
Not by marking alone. The complete emergency-stop device and safety architecture require documented behavior and validation.
How should terminals be checked?
Follow the stated termination method and torque, inspect conductor preparation and strain relief, and function-test every circuit.
Final decision
Approve the component only when the documented mechanical, electrical, environmental, usability, installation, and maintenance boundaries all fit the assembled system. Resolve unknowns through current manufacturer information and testing before production release.
