Problem with the Soft Start module mod for the SB220 from Harbach

[Army Curtis]

Francisco,

Very interesting point. It is easy for us in the US to forget sometimes that other countries use different power systems from what we have here. Your 220/380 volt system is similar to our 277/480 volts that is common here. But as you found out, 220/380 three phase is very different from the 120/240 volt single phase system so common in the US, and it certainly would cause 200 volt MOV's to explode.

Thanks very much for sharing your experience with us.

73,

Army - AE5P
Nacogdoches, the oldest town in Texas
acurtis at andersoft.com


*********** REPLY SEPARATOR  ***********

On 10/6/01 at 11:07 AM Francisco Viegener wrote:

>I bought in Ebay a SB220 Heathkit RFamplifier and after installing the
>Soft Start Module from Harbach I had a big ,skared,nice explotion, after I
>pluged it  in the 220volt normal AC pwer line here in Argentina.
>Everything was good connected but one of the varistor Z 2 (200VMOV) had
>exploded and maked a lot dirt inside and near the Start module.
>Harbach give you in the kid 1MOV for 390volts that is connected between
>the two end terminal of the power line were you have 220 volts,this is
>good for USA and for countries like mine that had 220/380volts.
>But then Harbach provide 2 Mov's rated for 200volts that are connected
>from each of this terminal to ground,and in my case one of this terminal
>is neutral to ground and the other is hot with 220 volts to ground so the
>MOVs rated 200volts is to low and that happen to explote it.
>Maybe this is not interesting for USA but it is important to all countries
>with 220/380volts.
>(In USA the voltage when the Ampl is connected to 220 volt the voltage
>between each terminal of the Power line and ground is 110 volts thats way
>MOVs rated for 200volts are good.)
>Thanks , and my intention was to help not to complain,
>Francisco LU3EEC.
>
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