Ametherm MS15 40004

The MS15 40004 inrush current limiting thermistor from Ametherm offers a maximum steady state current of 4.1A (up to +25°C), resistance of 40Ω ±25% (at 25°C) and a maximum recommended energy rating of 135J. Ametherm’s MegaSurge™ series of inrush current limiting NTC thermistors reduce costs and greatly simplify designs. In addition, they increase safety by eliminating the fire hazard associated with failed relays. While traditional thermistors are only certified for input voltages from 85 V_AC to 265 V_AC, UL recognised MegaSurge™ devices are certified for single and three phase input voltages up to 480 V_AC. These specifications are the highest of any single-solution inrush current limiting device on the market.

• Inrush current limiting thermistor
• Resistance of 30Ω (at 25°C)
• Maximum steady state current of 4.2A (up to +25°C)
• Maximum recommended energy of 135J
• Voltage ratings of 120VAC, 240VAC, 440VAC and 680VAC
• Actual energy failure at 270J
• 0.23Ω at 100% maximum current and 0.87Ω at 50% maximum current
• Body temperature of +150°C at maximum current
• Material type H (for beta and curve)
• Tolerance ±25%
• Dissipation constant of 49.4mW/°C
• Thermal time constant of 114mW/s
• Recognised by Underwriters Laboratories (UL) for ensured safety

Typical applications for the MS15 series include:

• Inrush current protection of power supplies
• Motor controllers, Audio amplifiers, Battery chargers and Frequency generators,
• Plasma cutting tools, MRI machines and Toroidal transformers

The below table gives the full specifications of the Ametherm MS15 30004 series: