ETENWOLF Zephyr S5 Tire Inflator Motor Load Current Test Report (2025-10-27)

Document Overview

Key Findings The ETENWOLF Zephyr S5 tire inflator was subjected to a motor load current measurement test across the full operating pressure range (10–160 PSI) on two production samples, confirming stable current draw throughout the working envelope. Samples tested: Unit 8# and Unit 9# Load…

Document type

Test Report

Prepared by

Daniel Wright

Published

July 22, 2026

Last reviewed

July 23, 2026

Topics

Motor Performance

Key Findings

The ETENWOLF Zephyr S5 tire inflator was subjected to a motor load current measurement test across the full operating pressure range (10–160 PSI) on two production samples, confirming stable current draw throughout the working envelope.

• Samples tested: Unit 8# and Unit 9#
• Load range: 10.0 PSI to 160.0 PSI (16 measurement points per sample)
• Peak current — Unit 8#: 10.1 A (at 60.0, 70.0, and 80.0 PSI)
• Peak current — Unit 9#: 10.8 A (at 80.0 PSI)
• Minimum current — Unit 8#: 6.8 A (at 10.0 PSI)
• Minimum current — Unit 9#: 7.1 A (at 10.0 PSI)
• Test date: 2025-10-27
• Overall verdict: Current profile is consistent between units; values remain within expected motor operating limits across all load points.

Test Overview

Test Equipment & Setup

Test Procedure

1. Pre-test: Confirm the S5 unit under test is fully assembled and connected to a calibrated DC power supply set to the rated operating voltage. Verify the current measurement instrument is zeroed and calibrated.
2. Initial load point: Set the pneumatic load (back-pressure) to 10.0 PSI and allow the motor to reach steady state.
3. Current measurement: Record the stable load current (A) displayed by the measurement instrument at the set pressure.
4. Step increment: Increase the load by 10.0 PSI increments, recording current at each step: 10.0, 20.0, 30.0, 40.0, 50.0, 60.0, 70.0, 80.0, 90.0, 100.0, 110.0, 120.0, 130.0, 140.0, 150.0, 160.0 PSI.
5. Repeat: Complete the full sweep for Unit 8#, then repeat the identical procedure for Unit 9#.
6. Post-test: Power down the unit, record ambient conditions and test date (2025-10-27), and archive data in the source Excel file.
7. Acceptance criteria: Current values must remain within the motor’s rated operating current range at all load points; no thermal shutdown or abnormal noise observed during the sweep.

Test Data & Results

The table below presents all 32 current measurements (16 per sample) exactly as recorded in the source file. Load values are in PSI; current values are in Amperes (A).

Observations: Both units exhibit the characteristic bell-curve current profile expected of a brushed DC motor under increasing pneumatic back-pressure. Current rises from a low no-load value, peaks in the mid-range (60–80 PSI), then decreases as the motor approaches stall-adjacent high-pressure conditions. Unit 9# reads consistently 0.3–0.5 A higher than Unit 8# across the mid-range, which is within normal unit-to-unit manufacturing variation. No anomalous spikes or discontinuities were observed in either dataset.

Conclusion

Document Information

Frequently Asked Questions

What is the peak load current of the ETENWOLF Zephyr S5 tire inflator motor?

In the 2025-10-27 load current test, the peak recorded current was 10.8 A, measured on Unit 9# at 80.0 PSI. Unit 8# peaked at 10.1 A between 60.0 and 80.0 PSI. Both values are within the motor’s normal operating range.

Why does the S5 motor current decrease at higher pressures?

The S5 uses a brushed DC motor whose current follows a bell-curve profile under increasing back-pressure. As pressure rises above the peak efficiency point (approximately 70–80 PSI), the motor’s rotational speed drops and torque demand decreases, causing current draw to fall. This is normal behavior and does not indicate a fault.

How consistent is the S5 motor current between different production units?

Testing of Unit 8# and Unit 9# showed a maximum inter-unit variation of 0.7 A across all 16 load points. Unit 9# measured consistently 0.3–0.5 A higher than Unit 8# in the mid-pressure range, which is within acceptable manufacturing tolerance for this class of motor.

What load range was covered in the S5 motor load current test?

The test covered 16 measurement points from 10.0 PSI to 160.0 PSI in 10.0 PSI increments, spanning the full operational pressure range of the ETENWOLF Zephyr S5 tire inflator.

Related Products

• ETENWOLF Zephyr S5 Tire Inflator — Product Page
• S5 Test Report — Sheet2 Data (same Excel workbook)