How to make sure compressed air heartbeat is okay?

Written by Sami Nyman, 18.03.2021

Ampere measurement of the compressor motor is the heartbeat monitor of a compressed air system. It is an inexpensive and efficient tool that can be used to optimize the energy use of compressed air production and equipment maintenance. Based on the measurements, the air output of the compressor can be adjusted as required and the power as low as possible per cubic meter of air produced. Proactive maintenance increases system life and efficiency.

The ampere meters included in Sarlin Balance Smart Management system provide real-time information on the operation of the compressed air system, so that the compressors can be operated smoothly with as few stops and starts as possible. In this way, the maintenance of the compressed air system can also be planned and implemented proactively. Smooth operation increases the durability of the compressors.

Ampere measurement reveals deviations

Ampere measurement serves as a maintenance tool for stable operation of the compressor. In general, amperage measurement can identify these three states of a compressor, namely stop, load and unload. In load mode, the compressor runs and produces air. In load mode, speed-controlled (20–100%) and turbo compressors (50… 90–100%) can usually adjust the air output. In unload mode, the compressor is idling, does not produce air, but uses 20-30% of its maximum power.

Switching between stop-load-unload-stop modes follows a certain pattern. If there are deviations in the switching, problems can be found in the mechanics of the machine. These situations can occur, for example, if the compressor is not loading at all, the suction regulator opens partially or stuck, the minimum pressure valve is out of order, the pressure in the oil separation tank drops too slowly, or the turbo’s guide vanes do not close properly.

Measurements reveal how well combined operation works

Ampere measurement also makes it possible to monitor energy consumption. Power of the compressor is calculated based on the ampere data, as long as the calculation uses a verified voltage and power factor (cosφ) value that varies according to the motor load.

The amperage measurement reveals how the combined operation of the compressors works. For example, is the simultaneous unloaded running correctly timed, does the low load running take place at the right time, or is the blow-off of turbo a compressor unnecessarily consuming energy. Energy efficiency is also reduced if the compressors output is not regulated at all or it is regulated by the compressor with high unload power.

Sarlin Balance system analytics supports proactive action

Compressor amperage measurement is standard in all Sarlin Balance Smart Management Systems. Amperage measurement can be used to anticipate hardware failure and perform corrective actions remotely to secure the operation of the entire system and ensure the best energy efficiency.

Sarlin systematically develops control tools and analytics for compressed air systems. Future solutions will make extensive use of the potential of automation and artificial intelligence.

Measurements indicate the heartbeat of the compressed air system

The data obtained from the measurements illustrates and tells when the compressor is working properly and when it is necessary to adjust the functions. Below are examples of compressor running cycles and the need for repair:


Speed-controlled compressor (green) speeds up too slowly and the second compressor (black) starts unnecessarily and remains unloaded. This wastes energy.

Compressor starts “stuck”. Suction regulator needs repair.

Oil-lubricated compressor unloads too slowly and wastes energy.

Compressor power (red) climb up at the same rate as pressure (yellow) increase. Overpressurizing waste energy and load compressors.