Description
The REXROTH PST625E.133W is a compact resistance welding controller with an integrated thyristor power unit and weld timer. It belongs to the PST 6xxE welding-control family and is designed for controlled AC resistance-welding applications. The referenced unit is identified as a Rexroth PST625E.133W Welding Control and is listed as a used runner-takeout unit.
The PST625E.133W combines welding-cycle timing, current/power control, monitoring, and thyristor-based power switching. The 133W variant uses external 24 VDC control power and is designed for demanding industrial welding installations. Bosch Rexroth documentation describes the PST 6xxE family as compact weld timers for robot, automatic, stationary, and manual welding equipment.
📊 Product Datasheet
| Parameter | Value |
|---|---|
| Brand | REXROTH |
| Model | PST625E.133W |
| Series | PST 6xxE Welding Control Series |
| Product Name | Resistance Welding Control |
| Product Type | Weld Timer with Thyristor Power Unit |
| Variant | 133W |
| Application | AC Resistance Welding |
| Control Supply | 24 VDC |
| Nominal System Current | 200 A |
| Maximum Rated Current | 230 A |
| Maximum Output Current | 400 A at 30% duty cycle |
| Rated Welding Power | Up to 155 kVA |
| Duty Cycle | Up to 50% |
| Cooling | Water-cooled configuration |
| Minimum Water Flow | 4 L/min |
| Maximum Pressure Drop | 0.2 bar |
| Protection Rating | IP20 |
| Main Connection | Box terminal, up to 95 mm² |
| Operating Temperature | 0 to +55 °C |
| Storage/Transport Temperature | -25 to +70 °C |
| Altitude | 0–2000 m |
| Weight | Approx. 8 kg |
| Country of Origin | Germany |
| Condition | Used / Runner Takeout according to referenced listing |
The published technical information identifies the PST625E.133-W with a 24 VDC control supply, 200 A nominal system current, 230 A rated current, up to 155 kVA power, 400 A output at 30% duty cycle, water cooling, and approximately 8 kg weight.
⚙️ Main Features
- ⚡ 24 VDC external control supply
- 🔥 Integrated thyristor power unit
- ⏱️ Integrated welding timer
- 🔧 Resistance-welding process control
- 📊 Welding-current monitoring
- 🎯 Phase-angle control and constant-current regulation depending on configuration
- 🔄 Single-spot and repeat welding modes
- 🤖 Suitable for robot and automated welding equipment
- 🏭 Suitable for stationary welding machines
- 💧 Water-cooled high-power configuration
- 🛡️ Integrated overvoltage protection
- 📡 Serial/programming interface options
- 🔌 Industrial cabinet installation
The PST 6xxE family supports welding modes such as single spot, repeat, and seam welding, while control modes include phase-angle control and constant-current regulation.
🛠️ Operating Procedure and Usage
The PST625E.133W should be installed as part of a complete resistance-welding system. It normally works together with a welding transformer, electrodes, pressure/gun system, PLC or robot controller, and the required welding-control signals.
Basic Installation and Operation
- 🔍 Inspect the controller, terminals, cooling connections, and housing.
- 🏷️ Verify PST625E.133W and the complete hardware identification.
- ⚡ Confirm the external 24 VDC control supply.
- 💧 Verify the cooling circuit and required water flow.
- 🔌 Check main power and transformer connections.
- 🤖 Connect PLC, robot, or machine-control signals.
- 🔧 Check electrode and welding-gun control signals.
- 📋 Load or verify the correct welding programs.
- ⏱️ Set weld time, squeeze time, weld time, hold time, and other required parameters.
- 📊 Configure current monitoring and tolerance limits.
- 🧪 Perform a low-risk commissioning weld.
- 🔥 Verify welding current, timing, electrode pressure, and weld quality.
- ▶️ Enable normal automatic production after successful testing.
🔌 Power-On / Power-Off Sequence
Power-On
⚠️ 1. Confirm the welding cell is safe.
🔍 2. Inspect the controller, transformer, electrodes, and cooling system.
💧 3. Start/verify the required cooling flow.
⚡ 4. Apply the 24 VDC control supply.
🔌 5. Energize the welding system according to the machine’s electrical procedure.
🖥️ 6. Check controller status and diagnostics.
📡 7. Verify communication with the PLC/robot.
📋 8. Verify the selected welding program.
🧪 9. Perform a controlled test weld.
▶️ 10. Enable automatic production only after all safety and process checks pass.
Power-Off
🛑 1. Stop the welding cycle.
🤖 2. Place the robot or machine in its safe maintenance position.
⚡ 3. Disable welding power.
💧 4. Maintain cooling flow for the required cooldown period where specified by the equipment design.
🔌 5. Isolate the electrical supply before maintenance.
🔒 6. Apply lockout/tagout before opening the cabinet.
💧 7. Isolate and depressurize the cooling circuit before disconnecting water connections.
📖 Product Usage Instructions
The PST625E.133W is particularly suited to resistance-welding systems where the welding current must be controlled accurately over a programmed welding cycle.
The controller can be operated through PLC/robot signals or manually, depending on the system configuration. Bosch Rexroth documentation describes single-spot operation in which a start signal initiates one welding schedule and must subsequently be removed and reapplied for another cycle.
Typical welding parameters include:
- Pre-squeeze time
- Main weld time
- Hold time
- Welding current
- Current tolerance
- Welding program number
- Electrode management
- Current monitoring
- Phase-angle parameters
- Constant-current regulation parameters
- Repeat/seam settings
For replacement applications, record the original controller configuration before removing the existing unit. A replacement with the same model number should still be checked for firmware, program settings, I/O configuration, cooling arrangement, and welding-transformer compatibility.
🔧 Maintenance Recommendations
💧 Cooling: Check water flow and temperature regularly. The published configuration requires a minimum water flow of approximately 4 L/min.
🔌 Electrical connections: Inspect high-current terminals for heat discoloration, looseness, and oxidation.
🔥 Thyristor section: Monitor abnormal heating and investigate unusual welding-current behavior.
⚡ 24 VDC supply: Verify the control voltage remains within the specified range.
📊 Welding current: Compare actual current against the programmed reference.
🧪 Weld quality: Check test welds periodically for consistency.
🔧 Electrodes: Maintain electrode alignment, pressure, and tip condition.
📝 Parameters: Keep a backup of welding programs and approved process settings.
❓ Common Questions & Answers
Q: What is the REXROTH PST625E.133W?
A: It is a resistance-welding control containing an integrated weld timer and thyristor power unit.
Q: What is the control voltage?
A: The control electronics use an external 24 VDC supply.
Q: What is the nominal system current?
A: The PST625E.133W is listed with a 200 A nominal system current.
Q: What is the maximum rated current?
A: Published technical information specifies 230 A rated current.
Q: What welding power can it handle?
A: The 133W configuration is specified for up to approximately 155 kVA.
Q: Is the unit air-cooled or water-cooled?
A: The PST625E.133W configuration is documented as water-cooled, with a minimum water flow of approximately 4 L/min.
Q: Does it contain a welding timer?
A: Yes. The weld timer is integrated into the PST control.
Q: Can it be used with a robot?
A: Yes. The PST 6xxE family is designed for robot, automatic, stationary, and manual welding applications.
Q: Does it support constant-current regulation?
A: The PST 6xxE family supports KSR/constant-current regulation as well as phase-angle control, depending on configuration and programming.
Q: What is the approximate weight?
A: Published information gives approximately 8 kg for the PST625E.133W configuration.
Q: What should I check before replacing an existing unit?
A: Check the exact model, variant, cooling method, control voltage, welding-transformer rating, current requirements, I/O configuration, welding programs, and firmware.
Q: Can the controller be replaced while energized?
A: Do not assume hot-swapping is supported. Isolate the welding system before removing or installing the controller.
🔟 Recommended REXROTH Welding Control Models / Series
- REXROTH PST625E.133W
- REXROTH PST625EW
- REXROTH PST625EL
- REXROTH PST610E
- REXROTH PST620E
- REXROTH PST650E
- REXROTH PST 6xxE Series
- REXROTH PS 6xxE Series
- REXROTH PSI 6xx0 Series
- REXROTH PRC7000 Welding Control Series
The PST 610E, PST 625E, and PST 650E families cover different resistance-welding power levels, while the newer PRC7000 represents Bosch Rexroth’s newer welding-control platform.
