Core Functions and Maintenance Analysis of OTC Daihen Robot Operation Box (FDOP Series)
In the OTC DAIHEN automated arc welding workstation, the robot operation box (commonly referred to as the “start box” or “external operation panel”) is the human-machine interaction hardware most frequently touched by operators in daily production. Its official series code is usually FDOP-00** (where ** represents the length of the connecting cable, such as 05 for 5 meters, 10 for 10 meters). Its internal core panel assembly series number is L21761.
The operation box integrates the workstation’s “Operation Preparation (Green)”, “Start (White)”, “Stop (Red)”, and the crucial “Emergency Stop (Large Mushroom Head)” functions. Because the workshop environment contains massive amounts of dust and oil, and the buttons are used at an extremely high frequency, the physical switches, LED indicator beads, and waterproof covers of the operation box are typical vulnerable consumables. When encountering button failures, indicator lights not illuminating, or a breakdown in the emergency stop circuit, accurately locating and quickly replacing internal original components via the exploded view is the most efficient maintenance method.
FDOP Operation Box Overall Appearance
Original Exploded View (I)
Original Exploded View (II)
II. Detailed Model Reference Table for FDOP (L21761) Start Box Original Parts
Please carefully check the corresponding sequence numbers in the exploded views above (Figure I, Figure II). This data table adopts a high-definition solid line and alternating zebra stripe design with a rigorous structure, ensuring that maintenance personnel can accurately look up the manufacturer specification codes of the required electrical components:
| Drawing No. | Official Ordering Model | Standard Accessory Name | Component Spec / Manufacturer Code Note |
|---|---|---|---|
| 1 | 4250-134 | Pushbutton Switch (Emergency Stop) | HA1E-V2S2R-TK2354 |
| 2 | 100-1649 | Selector Switch | HW1K-2B22 |
| 2-1 | 100-1655 | Key (Matching Key) | AS6-SK-132PN02 |
| 3 | 100-1650 | Anti-Rotation Ring | HW9Z-RL |
| 4 | 100-1643 | Illuminated Pushbutton Switch (Red) <Stop> | LA3L-M1C14R |
| 4-1 | 100-1644 | LED Bead (Red) | LFTD-2R |
| 5 | 100-1651 | Illuminated Pushbutton Switch (Green) <Operation Prep> | LA3L-M1C14G |
| 5-1 | 100-1652 | LED Bead (Green) | LFTD-2G |
| 6 | 100-1645 | Illuminated Pushbutton Switch (White) <Start> | LA3L-M1C14W |
| 6-1 | 100-1646 | LED Bead (White) | LFTD-2W |
| 7 | 100-1647 | Waterproof Cover (Transparent cover around button) | AL-DH6 |
| 8 | 100-1648 | Protective Cover (Anti-accidental touch hard shield) | AL-KH6 |
| 9 | L21761B01 | Case (Operation box rear shell) | L21761B01 |
| 10 | L21761B02 | Panel (Front brushed control panel) | L21761B02 |
| 11 | L9111C00 | Printed Circuit Board (Internal integrated PCB) | L9111C00 |
| 12 | L9111G00 | Short Circuit Connector | L9111G00 |
Operation Box (Start Box) Workshop Frontline Maintenance and Troubleshooting Core Standards:
- Beware of PCB short circuits caused by damaged waterproof covers: The waterproof cover No. 7 (
100-1647) is the first line of defense to block workshop iron filings and moisture from entering inside the buttons. Due to frequent pressing by operators, the silicone waterproof cover is highly prone to micro-cracks. Once damaged, the oil from the workers’ gloves will quickly seep into the illuminated pushbutton switch at the bottom, causing the button to jam in a normally closed state, and even triggering micro short circuits in the internal printed circuit board (L9111C00). The maintenance team should list the waterproof cover as a vulnerable part that must be replaced during quarterly inspections. - Dual-circuit detection of Emergency Stop Button (4250-134): If the control cabinet throws an external emergency stop alarm for no reason, and it still cannot be reset after releasing all safety door locks, there is a high probability that the internal normally closed contacts of the emergency stop button on the operation box are stuck or weakly connected due to aging. Please use a multimeter to perform independent continuity tests on the dual circuits of the
HA1E-V2S2Rswitch. If the resistance is abnormal, please immediately replace it with a brand new original emergency stop switch. Short-circuiting the emergency stop circuit for forced production is strictly prohibited. - LED Beads (LFTD series) flickering or not illuminating: When the operation prep (green light) or start (white light) fails to illuminate, it often gives the operator the illusion that the “machine has crashed”. This series of light beads are independent pluggable modules (e.g.,
100-1652). When troubleshooting, you can first unplug a good light bead and swap it for testing. If it is merely the lifespan of the bead that is exhausted, purchasing and replacing it individually is sufficient; there is no need to replace the entire button assembly.
️ Fast Access to Spot Quotes and Tech Support for Complete Sets of Operation Box Components
The robot operation box is the first command input end controlling the production rhythm. Insensitivity of the buttons will directly cause the production rhythm to drag. Whether you need to procure brand new original illuminated pushbutton switches, replace aging LED bead components, emergency stop switches, or need a complete FDOP start box assembly, you are welcome to provide your component sequence number or official model. Contact us directly to obtain the latest official standard factory quotes and today’s spot direct delivery service:


