Does a high temperature trip restart by itself?

HTM 02-01 (2026) asks for safety interlocks that stop the plant until a user resets the control system through a physical interface; the automatic restart it asks for is after the power supply is reinstated.

Do PSA compressors follow the same rules?

Yes. HTM 02-01 says compressors for PSA systems should comply with its medical air requirements.

Why does a hospital air compressor trip on high temperature?

Q: Why does the compressor feeding a medical air or PSA oxygen plant trip on high temperature, and what is checked?

HTM 02-01 (2026), the NHS England guidance, explains that PTFE rings and lubricating oils could decompose at high temperatures into toxic products, and that this can be countered by a temperature sensor on the cylinder head or compressor output with controls that cut the power when excessive temperatures are sensed.

Why does the compressor feeding a medical air or PSA oxygen plant trip on high temperature, and what is checked?

The HTM adds that manufacturer-specific data is needed to set the temperature range. Its plant monitoring list includes compressor temperature high and after-cooler temperature high as plant faults for each compressor, and compressors for PSA oxygen plants should comply with the same medical air requirements.

Cooling and maintenance in the guidance

Cooling airflow and room temperature. HTM 02-01 asks for plant siting with adequate airflow for air intake to the compressors, cooling of the compressed air by the after-coolers and cooling of the compressors, and for the ambient temperature of manifold rooms and plantrooms to be kept within 10 to 40 °C and no more than 10 °C above ambient. Medical air compressors generate considerable heat under maximum flow.
Cooling equipment. After-coolers are air-cooled and may need ducting with forced ventilation, and compressor cooling airflow may need to be provided mechanically by a duplex system so that a failure does not compromise plant operation.
Design temperature range. The HTM asks for manufacturers to be consulted on the operating temperature range and says refrigerator cooling may be required in extreme cases.
Maintenance. The Compressed Air Challenge maintenance fact sheet (May 2026 revision) says inadequate maintenance can lead to high operating temperatures, lists checking the operating temperature against the manufacturer's specification, and asks for compressor and intercooling surfaces to be kept clean, fans and water pumps inspected, and the cooling fins of enclosed motors kept free of debris, since poor motor cooling increases motor temperature and winding resistance.
Lubricant. In lubricant-injected rotary compressors, the same fact sheet says the lubricant removes most of the heat of compression, and only lubricant meeting the manufacturer's specification should be used.

After a trip

HTM 02-01 asks for safety interlocks that stop plant operation until the control system is reset through a physical interface by a user. For interruptions to the power supply, the HTM asks for automatic restart once the supply is reinstated.

On Ultra Controlo compressors

Each scroll compressor in an ULTRAAR SCA plant is air-cooled with a large passage radiator and a fan mounted on its main shaft, and has a high temperature safety valve; the control panel gives a failure signal for each compressor and has a thermal-magnetic circuit breaker with overload protection and manual reset. ULTRACECO SC compressors are air-cooled with an integrated high capacity fan.