Technical Specifications

FAQ

1. What is the main function of the Schneider Electric AS-P120-000 Power Supply Module?

The AS-P120-000 is a power supply module designed to provide regulated DC power for compatible industrial control systems. It accepts an AC input supply and provides a 24 VDC output for PLC components and associated control equipment. In an automation cabinet, the power supply module plays an important role in maintaining a stable electrical supply for the control system. A stable DC output helps prevent unexpected PLC resets, communication interruptions, module faults, and unstable operation caused by inadequate or fluctuating control power.

2. What input voltage does the AS-P120-000 support?

The AS-P120-000 supports an AC input range of approximately 95–253 VAC, with common nominal operating voltages of 115 VAC and 230 VAC. The input frequency range is 47–63 Hz, allowing the module to be used with common industrial AC power systems. Before installation, the actual cabinet supply voltage should be measured and compared with the module requirements. Correct input wiring is also important because incorrect voltage or wiring can result in abnormal operation, overheating, or permanent damage to the power supply.

3. What are the output voltage and current ratings of the AS-P120-000?

The AS-P120-000 provides a regulated 24 VDC output with a continuous output current of up to approximately 1 A, corresponding to roughly 24 W of available output power. The 24 VDC supply is intended for compatible control-system loads. When selecting this module for an existing installation, the total current consumption of all connected devices should be considered rather than looking only at the nominal voltage. If the connected load approaches or exceeds the rated output capacity for an extended period, the output may become unstable and the power supply may experience excessive thermal stress.

4. What should be checked if the AS-P120-000 has no 24 VDC output?

Troubleshooting should begin with the AC input side. Measure the voltage at the power supply input and confirm that it is within the specified operating range. Then check the input wiring, terminal connections, protective devices, and any upstream circuit breaker or fuse. If the input voltage is correct, measure the DC output with the downstream load isolated where appropriate. A short circuit or excessive load on the 24 VDC side can prevent the output from reaching its normal level. If the input supply and external load are both confirmed to be normal but the module still produces no output, the internal power supply circuitry may be defective and replacement may be required.

5. Why does the 24 VDC output of the AS-P120-000 drop under load?

A significant output voltage drop under load can be caused by excessive current demand, a downstream short circuit, wiring resistance, poor terminal connections, or an abnormal load connected to the DC supply. Begin by checking the total current consumption of the connected PLC and control modules. Disconnect non-essential loads one at a time and observe whether the output voltage returns to its normal level. The DC wiring should also be inspected for loose terminals, damaged conductors, or excessive voltage drop. If the output remains low even with an appropriate load, the power supply itself may have an internal fault or degraded components.

6. What can cause excessive output ripple on the AS-P120-000?

Excessive DC output ripple may be associated with an unstable AC input, excessive loading, switching loads connected to the same supply, poor grounding or wiring conditions, or deterioration of internal power supply components. High ripple can be particularly undesirable in control systems because sensitive electronic modules may become unstable or experience intermittent communication and signal problems. Troubleshooting should include checking the AC input stability, measuring the DC output under both light and normal load conditions, and inspecting downstream devices for abnormal current consumption. If the external conditions are satisfactory but ripple remains significantly higher than expected, replacing the power supply module is generally more practical than continuing to operate it in a questionable condition.

7. How can an overload condition on the AS-P120-000 be identified?

An overload condition may appear as a reduced 24 VDC output, intermittent PLC resets, unstable control modules, excessive heating, or a power supply that repeatedly stops and recovers. The first step is to determine the total DC current consumed by the connected equipment. Temporarily disconnecting selected loads can help identify whether a particular module or field device is drawing excessive current. It is also important to check for short circuits in field wiring and damaged downstream components. If the system operates normally when part of the load is removed, the total load should be recalculated and the abnormal device should be identified before returning the system to continuous operation.

8. What should be checked before replacing the AS-P120-000?

Before replacing the AS-P120-000, confirm that the problem is actually related to the power supply rather than the incoming AC source, protective device, wiring, terminal connections, or downstream load. Record the existing input and output wiring before disconnecting the module, and make sure the replacement unit has compatible electrical characteristics. Power should be completely isolated before removing or installing the module. After installation, verify the AC input voltage first and then measure the 24 VDC output without immediately reconnecting the entire load. Once the output is confirmed stable, reconnect the control-system components progressively and monitor the supply for voltage drop, abnormal heating, or repeated system resets.