Safety switches are the most critical hardware components of a Teach Pendant. Whether it is mechanical fatigue in an Emergency Stop (E-Stop) button from years of use, or oxidized contacts in a Deadman (Enable) switch, any failure in the safety loop will immediately halt robot operations and trigger "Safety Circuit" or "Dual Channel" faults.
This index provides a technical cross-reference for safety components across ABB, Fanuc, KUKA, and Yaskawa. We provide high-durability 3-position switches, locking E-stop knobs, and mode-selection key switches to restore your HMI's safety compliance.
1. Safety Circuit Diagnosis & Common Faults
| Component | Physical Symptom | Correlated System Error |
|---|---|---|
| Emergency Stop | Button does not lock or fails to pop up on rotation. | "E-Stop Pressed" error remains active; cannot reset. |
| Enable Switch | Loss of "click" feel; 2nd position does not engage motors. | "Enable Device Error" or "Dual Channel Mismatch." |
| Key Switch | Key is stuck or loose in the barrel. | Unable to switch between T1, T2, and Auto modes. |
2. Fanuc iPendant Safety Switch Index
Technical Note: Fanuc R-30iB (A05B-2255) switches often utilize integrated rubber boots. Exposure to industrial coolants can cause these boots to swell, physically jamming the Enable Switch. Note that internal PCB standoffs for the safety board differ between the #EMH and #EGN suffixes; ensure your switch mounting aligns with your specific housing revision.
- A05B-2255-C101#ES: Fanuc iPendant E-Stop Button - Twist-to-reset type.
- A05B-2518-C202#DS: Fanuc 3-Position Enable Switch - High-tactile response.
- A20B-2003-0740: Fanuc Mode Switch Contact Block.
3. ABB FlexPendant Enable & Button Spares
Technical Note: For ABB IRC5 (DSQC 679), the enable switch is an ergonomic bar. Internal structural revisions mean that older 3HAC17210-1 switches may require specific housing standoffs to be trimmed or adjusted if used in later-generation DSQC 3120 shells. Always verify the 3HAC serial number before final soldering.
- 3HAC028357-001 ES: ABB IRC5 E-Stop Replacement.
- 3HAC17210-1: ABB Universal Enable Device Switch.
- 3HNE00313-1 Key: ABB S4C+ Mode Selection Key Switch.
4. KUKA SmartPad & KCP Safety Components
Technical Note: KUKA KRC4 SmartPads use dual-redundant enable switches on the rear housing. If the 00-168-334 housing is cracked, it can cause the switch to be partially depressed, leading to "Safety Controller Logic Errors." On KCP2 units, the E-stop button is often hard-wired; ensure your soldering iron is set to low heat to avoid melting the internal contact carrier.
- SmartPad KRC4 ES: KUKA KRC4 Emergency Stop Unit.
- KCP2 Enable Switch: KUKA KRC2 Edition 2005 Enable Switch.
- KCP1 Key Switch: KUKA KRC1 Mode Selection Switch.
5. Yaskawa Motoman Enable & Key Switches
Technical Note: Yaskawa DX100/DX200 pendants use a 3-position switch that is highly sensitive to mounting depth. If the JZRCR-YPP01-1 shell is replaced, the switch must be recalibrated to ensure the "Middle Click" engages both safety channels simultaneously.
- JZRCR-YPP01-1 ES: Yaskawa DX100 Emergency Stop Switch.
- Yaskawa Deadman Switch: Yaskawa 3-Position Enable Device.
6. Technical Guide: Testing Dual-Channel Continuity
E-Stop Continuity
Test the two NC (Normally Closed) circuits. Both must open at the exact same moment when the button is pressed to avoid controller desync.
Enable Switch Logic
Verify the 3 stages: Position 1 (OFF) → Position 2 (ON/Motors Engage) → Position 3 (OFF/Emergency Panic). Use a multimeter to check both channels.
Sealing Compliance
Ensure the rubber boot (gaiter) is perfectly seated in the plastic housing. Oil ingress here is the leading cause of switch failure.
7. Safety Switch Repair FAQ
Q: Why does my robot show a "Safety Channel Mismatch" error after I replaced the E-Stop?
A: This usually happens if the two internal circuits of the E-Stop button are not triggering at the exact same time, or if the wiring is swapped. Robot safety controllers monitor both channels for simultaneity. Ensure you are using an OEM-spec switch with synchronized contacts.
Q: Can I replace the Enable Switch without soldering?
A: It depends on the model. Modern Fanuc iPendants often use plug-in connectors for the safety board, while older Yaskawa or ABB S4C+ units require precision soldering to the internal wiring harness.
Q: My Enable Switch feels "mushy" but the robot still runs. Should I replace it?
A: Yes. A "mushy" feel indicates that the internal mechanical spring or the silicone boot is degrading. If it fails in the "ON" position, it creates a dangerous safety violation; if it fails in the "OFF" position, your robot will be stuck in a stop-state.
Q: Are the E-Stop buttons universal across robot brands?
A: No. While the electrical principle is similar, the mounting diameter (e.g., 16mm, 22mm), depth, and the way they lock into the pendant housing are specific to each brand's hardware design.
Safety circuit won't reset? Contact our technical team for part identification or a professional diagnostic guide for your specific robot model.