Description
Providing reliable logic power to fail-safe PLC architectures, the Mitsubishi Electric QS061P-A2 safety power supply unit delivers regulated voltage specifically for MELSEC-QS Series control installations. This unit mounts directly onto the safety base unit to power the safety CPU and integrated I/O infrastructure, ensuring high-availability operation under strict safety-instrumented parameters. With integrated diagnostics, including an active ERR contact, and robust overcurrent and overvoltage protections, it acts as the stable electrical foundation for critical industrial automation processes.
Key Features
- Dedicated safety-series design optimized for the QS034B safety base unit.
- Wide AC input range (AC 200 to 240 V) with high tolerance for momentary power interruptions up to 20 ms.
- High-capacity DC 5V, 6 A output to feed demanding logic backplanes.
- Integrated protection mechanisms including automatic overcurrent and overvoltage clamp circuits.
- Dedicated diagnostic ERR relay contact for real-time remote status monitoring.
- Clear front-panel LED diagnostics for visual status identification (Green for normal, Off for abnormal).
Applications
- Automotive welding and assembly safety cells
- Heavy industrial press and metal forming operations
- Large-scale material handling and automated logistics systems
- Fail-safe processing and chemical batch monitoring
Technical Specifications
| Parameter |
Specification Value |
| Manufacturer |
Mitsubishi Electric |
| Model Number |
QS061P-A2 |
| Mounting Slot |
QS Series Power Supply Slot |
| Compatible Base Unit |
QS034B |
| Input Supply Voltage |
AC 200 - 240 V (-15% to +10%) |
| Input Frequency |
50/60 Hz (+/- 5%) |
| Input Max Apparent Power |
125 VA |
| Inrush Current |
20 A within 8 ms |
| Rated Output (DC 5V) |
6.0 A |
| Overcurrent Protection |
6.6 A or more |
| Overvoltage Protection |
5.5 to 6.5 V |
| Efficiency |
Over 70% |
| Momentary Power Failure Ride-Through |
Within 20 ms |
| Insulation Resistance |
10 MOhm or more (at 500V DC Megger) |
| Dielectric Withstand Voltage |
AC 2830 Vrms / 3 cycles (Input-LG and Output-FG) |
| External Dimensions (H x W x D) |
98 mm x 55.2 mm x 115 mm |
| Product Weight |
0.40 kg |
| Shipping Weight (Calculated) |
1.4 kg |
Connections and Interfaces
| Terminal / Port |
Functional Assignment / Rating |
| Main Supply Terminals |
AC Line / Neutral (AC 200 - 240 V Input) |
| LG Terminal |
Line Ground (Noise Filter Ground) |
| FG Terminal |
Frame Ground (Chassis Ground) |
| ERR Contact |
Diagnostic fault relay output (Rated DC 24 V, 0.5 A) |
| Terminal Screws |
M3.5 Threaded Connection type |
Empirical Engineering Insights
Alternative Models & Compatibility
The QS061P-A2 is dedicated exclusively to the MELSEC-QS safety series platform. It is keyed physically and electrically to slot into the QS034B safety base unit and cannot be utilized on standard Q-Series (non-safety) base units. Trying to force insertion into a standard base unit can result in physical structural damage to the connector interfaces.
Application Pitfalls & Engineering Notes
This module features an inrush current envelope of 20 A lasting up to 8 ms. If powering multiple racks simultaneously, upstream circuit protection must be rated using D-curve or high-inrush magnetic delay breakers to avoid nuisance tripping during system hot-starts. Be mindful that the internal fuse is user-replaceable; however, a blown fuse typically points to an underlying backplane overcurrent fault that must be resolved before powering up again.
Commissioning & Wiring Tips
Always ensure that the LG and FG terminals are tied to a dedicated functional ground path to prevent high-frequency noise from corrupting logic signals, which can manifest as inter-module communication errors. Use M3.5 ring-tongue terminals and torque all connections to the manufacturer standard of 0.68 to 0.98 N-m for optimal contact resistance.
Installation Guidelines
CRITICAL WARNING
Isolate and lock out all primary AC power feeds before mounting or terminating this power supply. Verify zero-energy state with a calibrated voltage meter before handling connections. Failure to fully discharge power lines prior to termination can result in fatal electrical shocks and component destruction.
1
Hook the upper mounting tab of the module into the base unit's guide slot.
2
Firmly press the bottom of the module onto the base unit until it clicks securely into place, ensuring the backplane connector is fully engaged.
3
Tighten the module fixing screw (M3) to ensure stability against high-vibration industrial environments.
4
Wire input terminals, LG, and FG using M3.5 terminal lugs, verifying polarity and tightening to the rated torque spec.