Ametherm SL22 2R508

The SL22 2R508 inrush current limiting thermistor from Ametherm offers a maximum steady state current of 8A (up to +25°C), resistance of 2.5Ω ±20% (at 25°C) and a maximum recommended energy rating of 90J. The Ametherm SL series suppresses surge currents that occur when electrical circuits are switched on, preventing serious damage to sensitive electronic components if their rated current values are exceeded. Connected in series with the load, at “switch-on” they limit the current due to its relatively high cold resistance. As a result of current flow, the thermistor self-heats and in turn reducing its resistance value so that once the initial surge current has been safely held off, the resistance in the thermistor is maintained at a low value to maximise efficiency

• Inrush current limiting thermistor
• Resistance of 2.5Ω (at 25°C)
• Maximum steady state current of 8A (up to +25°C)
• Maximum recommended energy of 90J
• Voltage ratings of 120VAC and 240VAC
• Actual energy failure at 200J
• 0.06Ω at 100% maximum current and 0.14Ω at 50% maximum current
• Body temperature of +162°C at maximum current
• Dissipation constant of 32.4mW/°C
• Tolerance ±20%
• Thermal time constant of 94mW/s

Typical applications for the SL series include:

• Limit current inrush to PSUs and battery chargers
• Lighting circuits and thermostat protection
• Electric motor soft start

The below table gives the full specifications of the Ametherm SL22 2R508 series: