Inrush Current

Ametherm’s Inrush Current Limiters

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Inrush Current Limiters

PTCs

About Inrush Current Limiters

When you switch on an electrical device, it goes through an initial surge of current, also called inrush current. If this surge is too strong, it can harm the device. Inrush Current Limiters (ICLs) work by raising the circuit’s resistance when there’s a lot of current. This reduces the current flow and shields the device.

Many applications, including power supplies, motors, and other devices that experience high inrush currents, frequently rely on ICLs. They play a critical role in safeguarding various electrical devices, preventing damage, and keeping power surges in check.

Here are some advantages of using inrush current limiters:

  1. Shield devices from damage caused by inrush current.
  2. Stop power surges.
  3. Power supplies work more efficiently.
  4. Act as cost-effective protection.

If you’re designing an electrical device that’s susceptible to high inrush current, it’s a good idea to include an inrush current limiter. It’s a straightforward and effective way to guard your device against potential harm

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Standard Surge Limiter

Standard Surge Limiter

The Standard Surge Limiter Series includes devices that protect electrical systems from harmful power surges. These surge limiters have UL Ratings for safety and performance. They offer up to 90 Joules of energy and can handle 10 Amps of current, providing protection against voltage spikes.

You can use these Inrush Current Limiters in various applications, including residential, commercial, industrial, healthcare, renewable energy, and electric vehicle systems.


MS35 Series

MS35 Series

The MS35 Series inrush current limiters can handle up to 800 Joules of energy and current from 10 A to 50 A. They’re built to last, even in demanding high-power situations.

In alternative and green energy setups, the MS35 Series plays a vital role. It prevents sudden power surges when transferring energy from sources like wind turbines and solar panels. By controlling the energy flow into batteries, inverters, and other storage components, these limiters keep the system stable and reliable.


AS Series

AS Series

The AS Series is designed to protect electronic components, including power supplies, transformers, rectifiers, pre-charge circuits, and more, from inrush currents. These UL-rated Inrush Current Limiters provide protection ranging from 230 to 1000 Joules and can withstand current levels of 10 to 50 Amps.

They ensure component safety and extend operational lifespan. With their compact design, the AS Series offers a cost-effective solution for inrush current mitigation. These ICLs are highly durable and suitable for various applications. Ametherm’s AS Series is a reliable choice for engineers and designers seeking efficient inrush current limiting solutions.


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Mega Surge Inrush Current Limiters

MegaSurge Series

The MegaSurge Series of inrush current limiting NTC thermistors offer a simple and cost-effective alternative to using wirewound resistors in combination with timers and relays. These thermistors not only reduce costs but also simplify designs significantly. Moreover, they enhance safety by eliminating the fire hazard associated with failed relays.

Unlike traditional thermistors that are certified for input voltages ranging from 85 VAC to 265 VAC, the UL-recognized MegaSurge devices are certified for both single- and three-phase input voltages up to 480 VAC. This expanded voltage certification provides greater flexibility in application.

In terms of performance, MegaSurge devices have exceptional capabilities. They can withstand high steady-state currents of up to 36 A and handle input energy of up to 300 J. These specifications represent the highest among any single-solution inrush current limiting device available in the market.

The MegaSurge series targets a wide range of applications, including the inrush current protection of power supplies, motor controllers, audio amplifiers, battery chargers, frequency generators, plasma cutting tools, MRI machines, and toroidal transformers. These thermistors offer reliable and efficient inrush current limiting for various electronic systems.


MCL20 500100 PTC Inrush Current Limiter

Inrush PTC Thermistor

The MCL20 500100-A is impressive because of its high voltage rating, allowing it to handle multiple instances of maximum inrush current without losing its performance.

One of its main advantages is the quick reset time. Being a PTC thermistor, it swiftly resets without causing a large inrush current because it starts with a high resistance state. This feature boosts reliability and stability in high-voltage applications.

The MCL20 500100-A provides designers with a more compact and cost-effective solution. It has a diameter of 19 mm, a maximum height of 9 mm, and a lead spacing of 7.8 mm. This means you don’t have to use a power resistor, relay, and timer on a single circuit to achieve the same results.

This thermistor is made specifically for applications that need inrush current control and protection against overcurrent in high-voltage situations. It’s perfect for welding equipment and plasma cutters operating in the 480 V to 930 V range.


MM35-DIN in a DIN Block

MM35-DIN

The MM35-DIN Series made for heavy-duty industrial work, where you need a lot of power. These Inrush Current Limiters handle continuous currents from 50A to 80A at 680V RMS and store energy up to 1,200 joules. They do a great job at managing the high power levels you find in factories and industrial places.

The MM35-DIN Series can handle more energy and is perfect for distributing power. They work well in systems that get turned on once a day because they can handle a lot of electricity continuously. You won’t need extra circuitry since they are a single part solution.

You can use these limiters in both single and three-phase systems, including things like AC motors, transformers, and power supplies. The Maximum Power Ratings Chart gives you more information on where to use them. Installing the MM35-DIN Inrush Current Limiters is easy; you only need a screwdriver to mount them on DIN blocks in a power control box.

Whether you’re dealing with three-phase or single-phase power in an industrial setting, the MM35-DIN Series Inrush Current Limiters are the right choice for high-power needs.


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MiniAmp Inrush Current Limiter

MiniAmp Series

The miniAMP series offers small inrush current limiters designed for tight spaces. These compact devices work well in situations where you don’t have much room on a circuit board. The miniAMP inrush current limiter is an affordable way to protect relays, diodes, and fuses from current surges.

You can get them in three sizes: 3mm, 5mm, and 8mm, and they are very light, weighing as little as 0.06 grams. The miniAMP series has cold resistance that ranges from 5 ohms to 220 ohms.

These inrush current limiters have a continuous current rating of 250 mA to 3 Amperes and can handle up to 20 joules of energy. They work reliably within a temperature range of -40 to +150 degrees Celsius.

The miniAMP inrush current limiters come with leads that are either kinked or straight, and the standard lead length is 1/2 inch. You can buy them in bulk or on a Tape and Reel for easy handling.


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RTI SURGE-GARD Inrush Current Limiters

RTI SURGE-GARD™ Inrush Current Limiters

RTI’s SURGE-GARD™ Inrush current limiting devices from specially designed metal oxide ceramic materials, and they effectively control high inrush current surges.

The recovery time for SURGE-GARD™ devices varies depending on factors like the device itself, how it’s mounted, and the surrounding temperature. We recommend allowing at least 60 seconds for them to cool down. These devices come with features like reducing the required peak forward surge current rating, reducing noise, and preventing fuse failures.

RTI’s SURGE-GARD™ Inrush current limiting devices offer various installation options:

  • Thru-hole leads
  • Insulated/uninsulated configurations
  • Standoffs
  • Preformed leads

It’s important to know that you shouldn’t connect SURGE-GARD™ devices in parallel because one unit would carry most of the current. These devices offer reliable protection and can be easily added to different power supply setups.


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BigAmp Inrush Current Limiters

bigAMP Series

The bigAMP Series effectively manages high initial surges of electricity when you turn on a device. It starts with high resistance and quickly reduces it once the regular current is flowing.

In devices like power supplies, the initial surge happens because of large capacitors and the power coming in. The thermistor’s resistance drops almost instantly within milliseconds during this surge. This makes sure the regular current flows smoothly with very little power loss.

The bigAMP Inrush Current Limiter can handle up to 260 joules of energy and can handle a steady current of 36 amperes. It’s useful in various applications like power supplies, motors, power backups, variable speed drives, and any equipment that needs protection from sudden surges of power.

Ametherm’s bigAMP Inrush Current Limiters are specially designed thermistors that can continuously handle up to 36 amperes of current and up to 260 joules of energy.