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Reviews Categories | Filters, AC Line | Ameritron Step-Start Inrush Current Protector ICP-240 Help

Reviews Summary for Ameritron Step-Start Inrush Current Protector ICP-240
Ameritron Step-Start Inrush Current Protector ICP-240 Reviews: 12 Average rating: 3.8/5 MSRP: $79
Description: Ameritron's Step-Start Inrush Current Protector stops damaging inrush current. By starting your linear amplifier through a high power current limiting resistor and then shorting the resistor with a relay, you get a start up sequence that's easy on your tube and power supply components.

Now you can add this protection to your amplifier without complicated wiring -- you don't even have to take the cover off. Simply plug your amplifier power cord into the Ameritron Inrush Current Protector. By limiting heavy inrush current to safe low level, you'll get a longer lasting amplifier. You might avoid replacing expensive tubes and components. Avoiding just one repair job could pay for this extended protection.

Momentary high-voltage "spikes" in the ac line can also cause damage to your amplifier. The Ameritron Inrush Current Protectors have built-in varistors to absorb these spikes before they can cause damage. Works with nearly all linear amplifiers. The Ameritron ICP-240 is for 240 volt wired amplifiers. Limits current to 12 amperes during heavy draw inrush period. 20 amperes continuous operating current.
Product is in production.
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KE0ZT Rating: 4/5 Feb 6, 2018 08:55 Send this review to a friend
Good Idea, But QC Problem  Time owned: more than 12 months
I ordered the ICP-120 (120 volt version) to lessen the surge on my equipment. Instead of functioning correctly, it oscillated, with the relay clicking on and off. I returned the unit to the factory and they fixed it, saying that the relay was defective. It works ok now. Apparently, others have also had trouble with this inexpensive relay.

An outboard inrush protector is a good idea for a product. You don't have to modify your existing equipment. I wish the delay were just a little bit longer, but I'm sure it helps as is. I may buy another in the future -- perhaps redesigning it to work even better.
N9ZI Rating: 5/5 Apr 8, 2016 17:20 Send this review to a friend
Works Great  Time owned: more than 12 months
Have had it for a few years now, switch my amp on & off with no complaints - am happy with what it is doing.
W9OWO Rating: 5/5 Apr 8, 2016 06:58 Send this review to a friend
Using as Master Switch for Operating Desk  Time owned: 0 to 3 months
I have a 20A power strip that feeds some walwarts and my Astron PS that serves two radios and numerous 12V accessories. My ICP-120 is the only on/off control for the entire desk. I believe that everything benefits from the reduced startup shock, plus I have only one switch to startup or shutdown. The relay "click" just tells me it's working. I feel that the price is fair and the product is well made.
W9RAC Rating: 5/5 Apr 14, 2015 19:09 Send this review to a friend
Works like a charm  Time owned: 0 to 3 months
I have a ameritron 811H amp that is a backup to my alpha 8410. I have it set to 240 volt for convenience. Every time I powered it up the power surge thump scared the bejeebers out of me. I decided to do something about it before it destroyed itself. Once plugged in to ICP 240 the problem is solved!
K7UF Rating: 3/5 Mar 13, 2014 19:55 Send this review to a friend
Poor value for the price.  Time owned: 0 to 3 months
Re-write of my review with all of the words in the correct order :-)


Just received one of these and although it will work (I suppose), it is way overpriced for what it is.

Basically, you leave the amplifier turned on, and use the switch on the ICP-240 to switch on and off. There is a relay with N/O contacts in series with the power and a resistor across those contacts. When you apply power, it flows through the resistor, which limits the current. A few milliseconds later, the relay closes and shorts out the resistor, applying full power.

The cheap and nasty relay used is hardly a precision device. I would guess that different instances of it will have wildly different closing times, so its really not very precise.

The documentation claims that initial current is limited to 6A.
The resistor is 20 ohms. When I learned Ohm's law, a 20 ohm resistor with 240v across it would pass 12A. I think this is actually what the design calls for and the documentation is wrong, because it specifies 12A for the 120v version.

In series with the resistor is a 2A (slow-blow) fuse. Keep whacking that with 12A, and it will blow.

I have to say I am not impressed, either by the design, or by the execution.

About $10 would be a reasonable price for this.

For the price paid, I would expect a better quality relay. I would expect a simple timer for more precise control over the delay time triggered by the voltage drop across the resistor and the fuse should really be properly rated.

I may just re-build the whole thing. The box isn't too bad.
KM4AH Rating: 5/5 Feb 15, 2014 15:13 Send this review to a friend
No Complaints  Time owned: more than 12 months
The relay in mine started sticking. I looked at the paperwork and I have been using it on average more than once a day for eight years. I ordered another relay. Maybe it will go another eight years.
W0FEN Rating: 5/5 Jul 29, 2013 10:09 Send this review to a friend
Works as Designed  Time owned: more than 12 months
I bought and installed one of these for use with my amp a couple of years ago. It has worked from day one and I hope it continues.
W4VR Rating: 3/5 Dec 4, 2012 18:29 Send this review to a friend
OK  Time owned: 0 to 3 months
I bought one of these units a few days ago to use with my PW-1 amplifier. I bought it not so much for the inrush current protection as I did for the voltage surge protection that is missing in the PW-1. I plugged the thing in and all I could hear was relay chatter. I opened it up and found that the relay contact arm was loose on the relay frame. I tightened the spring and put little pieces of tape on the relay contact arm to eliminate the chatter. I finally got it to work OK. If Ameritron would check out every unit before shipment we wouldn't have this problem, despite the fact there was a QC label inside the unit...the inspector must have been sleeping on the job.
VK4CC Rating: 0/5 Nov 13, 2011 19:51 Send this review to a friend
CAUTION!!!  Time owned: 0 to 3 months
Thank you very much to those posting in this thread. I have just received two of these units and after reading the comments here I opened one up. The spring hadn't come loose, the whole relay arm was hanging by the spring and the contact on that arm was brushing one of the 240v input wires. I immediately opened the other and found that it was exactly the same. I have replaced the relay components but frankly am afraid to feed 240v into the bloody things.

I photographed the loose items before I fixed them in place and will send a report back to my supplier, whom I view with great respect (thanks Diana). She can decide whether to inform MFJ.

When deciding whether to buy these items I emailed them to inquire about the availability of the IPC-240 with plug and socket to suit Australian fittings. I was told to cut the plug off the cable and fit an Australian one. Fair enough but then I pointed out that the socket on the unit wouldn't accept the Australian plug on my amp I was told that that was the way they are and if I am not happy with that, don't bother buying one. Great customer relations.

I will try to find some adapters and work up enough courage to turn on the power. If they work as promised I will update my report in a few months. In the meantime I have learned one valuable lesson about MFJ/AMERITRON,, The QC sucks as has been pointed out before and ALWAYS OPEN THEM UP AND CHECK FOR YOURSELF.

WB1CQW Rating: 2/5 Sep 26, 2010 06:47 Send this review to a friend
time to modify design  Time owned: 0 to 3 months
This is a followup to a previous review of the IPC-240. In speaking with the Ameritron factory representative, he politely verified that the unit should not have a REPEATED clacking, loud enough to wake up the dead, or to hear from three rooms away, whichever comes first. I mentioned that with the huge power demand on this unit, required to handle a full kilowatt, it needs to work 100%. A failure under the right conditions could even lead to a fire. He speculated that perhaps the spring had slipped out of place in shipping. I suggested to him that if this unit has a demonstrated history of returns, then perhaps it would be in both Ameritron's and the customer's interest to discontinue production or else modifify the spring assembly to eliminate the defect. Still, there is no alternative product available, and I am awaiting my third unit to test it.
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