Description
Astec LPQ172 | 110W Quad-Output Power Supply
Product Introduction
When replacing a legacy power supply, matching the output rails is only part of the job. The Astec LPQ172 is a four-output AC-DC supply intended for equipment that requires several DC rails from a single chassis-mounted unit.
The LPQ172 provides +5 VDC, +12 VDC, −12 VDC, and a fourth adjustable output. Astec documentation specifies 110 W operation with convection cooling and a higher 175 W rating when the required forced-air cooling is provided. That distinction is important: the maximum current figures cannot be treated as continuously available under every cooling arrangement.
For maintenance teams, the LPQ172 is primarily a legacy equipment replacement component. Verify the installed output loading, fourth-rail setting, connector pinout, and cooling arrangement before approving a substitute.
LPQ172
Key Technical Specifications
- Model: LPQ172
- Manufacturer: Astec
- Series: LPQ170
- Power Supply Type: Enclosed/chassis-mount AC-DC converter
- Number of Outputs: 4
- AC Input Range: 85–264 VAC
- Output 1: +5 VDC, adjustable range 3.3–5.5 V
- Output 1 Current: 15 A convection; 30 A forced air
- Output 2: +12 VDC, 6 A convection; 8 A forced air
- Output 3: −12 VDC, 1.5 A convection; 3 A forced air
- Output 4: Floating, adjustable 3.3–25 VDC; factory-set to 5 V
- Output 4 Current: 2 A convection; 5 A forced air
- Total Output Power: 110 W convection; 175 W with specified forced air
- Regulation: ±2% on the +5 V rail; ±3% on the +12 V and −12 V rails, per datasheet conditions
- Ripple/Noise: 50 mV peak-to-peak on +5 V; 120 mV peak-to-peak on +12 V; see datasheet for remaining rail conditions
- Remote Sense: Supported on the main output
- Remote Inhibit: Supported
- Power-Good Signal: Provided through the control connector
- Dimensions: Approximately 216 × 108 × 38.1 mm (8.50 × 4.25 × 1.50 in.)
- Mounting: Chassis mount
- Cooling: Convection or specified forced-air cooling
- Operating Temperature: 0°C to +70°C, with derating according to the applicable datasheet
- Minimum Load: Required; requirements depend on output and operating conditions
- Output Connector: Molex main-output connector; verify mating connector and pinout against the OEM drawing
- AC Connector: Molex 3-position connector
- Weight: Approximately 0.91 kg (2 lb)
These ratings are drawn from the Astec LPQ172 datasheet. Forced-air ratings depend on the specified cooling conditions, and the adjustable fourth output is factory-set to 5 V unless configured otherwise.
Global Sourcing & Live-Test SOP
For a used or surplus , acceptance should establish the exact model, electrical condition, output stability, and ability to support the required load profile.
5.1 Inbound Verification
- Photograph the complete nameplate and model designation.
- Confirm , not a related LPQ170-series variant.
- Record serial number and any revision or configuration markings.
- Inspect the PCB, housing, mounting holes, and connectors for damage.
- Check for corrosion, contamination, overheated components, or prior repair.
- Verify whether the unit includes a fan cover or other cooling accessories.
- Confirm the supplied unit’s connector configuration against the original installation.
- Request traceability information where available.
5.2 Power-Up and Electrical Inspection
- Confirm the AC input rating and wiring arrangement before energizing.
- Use an appropriately protected AC test setup.
- Inspect the AC connector and protective-earth connection.
- Check startup behavior and abnormal noise or odor.
- Measure all four outputs with suitable test equipment.
- Verify the fourth output’s actual factory setting.
- Confirm the main-output remote-sense wiring is configured correctly.
- Check for abnormal current draw, overheating, or unstable output.
- Do not exceed the convection-cooled rating unless the specified forced-air arrangement is present.
5.3 Load Simulation and Output Verification
- Test each output independently using suitable electronic loads.
- Confirm output voltage and polarity against the datasheet.
- Verify that the total load remains within the applicable power rating.
- Test the +5 V rail under representative loading.
- Confirm +12 V and −12 V rail stability.
- Verify the adjustable fourth output at the required setpoint.
- Check output regulation and ripple under the applicable test conditions.
- Verify remote inhibit and power-good functions where required by the application.
- Record output voltage, load current, cooling method, and test results.
5.4 Extended Run and Final Preparation
Where a suitable test fixture is available, perform an extended powered run under representative loading.
Monitor:
- Output voltage stability
- Ripple or abnormal noise
- Temperature rise
- Unexpected shutdowns
- Fan/cooling performance, if applicable
- Connector and terminal condition
Record the test date, serial number, applied input voltage, load distribution, cooling method, and measured outputs. Protect connectors and exposed electronics with suitable packaging for shipment.
Field Engineer’s Pitfall Guide
❗ Do not use forced-air ratings without the required cooling
The ‘s 175 W rating depends on specified forced-air cooling. Under convection cooling, the documented total output rating is 110 W. Confirm the cooling arrangement before applying the higher current limits.
❗ Verify the fourth output’s actual setting
The fourth output is adjustable over a broad range and is factory-set to 5 V. Do not assume the output is configured for the same voltage as the original unit without measuring it or checking the configuration documentation.
❗ Check minimum load and total power—not just individual rail current
The has minimum-load requirements, and the maximum current ratings cannot all be assumed simultaneously available under every condition. Confirm the complete load distribution and total wattage against the datasheet before commissioning.
Intent-Driven FAQ
What is the Astec ?
The is a four-output AC-DC switching power supply in Astec’s LPQ170 family. It provides multiple DC rails for electronic and legacy equipment.
What output voltages does the provide?
It provides +5 VDC, +12 VDC, −12 VDC, and a floating adjustable fourth output factory-set to 5 VDC.
What is the input voltage range?
The datasheet specifies 85–264 VAC. Verify the actual unit’s nameplate and wiring before energizing.
Is the rated for 175 W?
The is rated for 110 W with convection cooling and up to 175 W with specified forced-air cooling. The cooling arrangement and load distribution must meet the datasheet requirements.
Is the fourth output fixed at 5 V?
No. It is adjustable from 3.3 to 25 VDC and is factory-set to 5 V. Verify the actual output setting before connecting the supply to the load.
Is the obsolete?
DigiKey lists the as obsolete. Used and surplus units may still be available through independent suppliers, but current OEM support and availability should be confirmed before planning a long-term replacement strategy.
What should I verify before buying a used ?
Confirm the exact model, input connector, output connector and pinout, all four output ratings, fourth-rail setting, cooling configuration, physical condition, and documented load-test results. Ask whether the unit was tested under representative load rather than merely powered on.
Bottom Line for Buyers
The is a legacy four-output AC-DC power supply with +5 V, +12 V, −12 V, and an adjustable fourth rail. It is rated for 110 W with convection cooling and up to 175 W with specified forced-air cooling.
For procurement, match the full model number, connector arrangement, output settings, and cooling conditions. Request a documented multi-rail load test before accepting a used or surplus unit as a production spare.
