Descrizione
GENERAL INFORMATION Bimetallic thermal protectors are constructed to protect electrical equipment against sudden and abnormal temperature rises. Their operation is mainly based on the expansion and contraction of the sensing element contained within the housing (bimetallic foil). As the temperature rises, the surface of the foil with the greater coefficient of expansion begins to elongate: however, the natural extension of the foil is hindered by the part of the foil with the lower coefficient of expansion. The two surfaces therefore begin to contract, until the more sensitive part flexes the less sensitive one.
OPENING CONTACTS At this instant, the sensing element quickly flexes (quick snap), opening the contact and interrupting the power supply.
RESTORATION OF CONTACT When the temperature conditions prior to the danger threshold have been restored, the protector, taking advantage of the same principles listed above, but in reverse order, returns to close the contact, allowing the circuit to be energized.
NO CONTACTS (Normally Open) In normally open contact applications, the process is reversed.
TYPICAL APPLICATIONS Electric motors, transformers, coils, audio-video amplifiers, home appliances, electronic boards (hard terminals), electrical equipment in general.
To learn more, click on the links to our articles:
WHAT CAUSES CONTACTS TO OPEN AND CLOSE IN A BIMETALLIC DEVICE
THERMAL PROTECTORS AND JOULE EFFECT
LA NORMATIVA EN60079-15
THE COMPRESSIVE STRENGTH
THE TOLERANCE ON TEMPERATURE
THE SENSITIVE SIDE OF THE PROTECTOR
RESET AND ROOM TEMPERATURE
OPENING AND CLOSING CONTACTS OR ON/OFF?
CYCLES: THE LIFE OF A THERMOSTAT
SAFETY IN ELECTRIC BLANKETS
IN CASE OF FIRE WHAT HAPPENS TO THE THERMAL PROTECTOR?
E SE LA NORMATIVA IMPONE GAS MENO INQUINANTI MA PIU’ INFIAMMABILI?
PRODUZIONE CINESE SIGNIFICA PER FORZA BASSA QUALITA’?
THE ENGINES AND THE PAINT
LE DIRETTIVE ATEX
IP68 THERMAL PROTECTORS
THE DOWNGRADE IN DETAIL
THERMAL PROTECTORS WITH DUAL PROTECTION
