Home Forums General Discussion Technical Questions Replacing Siemens Soft Starter

Changing a siemens soft starter tomorrow. Just wanted to know if anyone that has done this before ran into any problems or may have any suggestions.
Is there a learn procedure on first start up?
Any parameters need to be changed?

Im replacing a Siemens 72G Soft starter with the same model.

Overload current is FLA off motor data tag. Make starting current 3x OL amps, some versions of software ask for a percentage of FLA, then make it 300%. You can make it as high as 4x if the motor is taking too long to get up to speed, usually big dry units. Make on delay and off delay the same as the old one but a good rule of thumb is set them to 0 on any microprocessor controller.

Rotation=ABC/CBA, you may have to change that. It'll tell you if it's wrong. IDWT mentions starting amps. If your data tag just says "AMPS", then 125% of that value is OL current. Also, are you changing the starter because the LCD display was blank, but you had 3phase incoming power? If so, before you yank the old one out, measure between terminals 1&3 and IF you have 120VAC, you only need change the logic card, not the whole shebang (obviously for future reference). Setting parameters would be the same though.

Thanks for the help, it was a very simple swap. I didn't know they came with a installation manual. The only thing I noticed was that the manual recommended I change the starting amps to 250%. Other than that you guys were spot on. Thanks

elmcannic is dead on the logic card going blank. Upper right hand corner a resistor capacitor opens up. Read about it here and everyone was having the same problem. And I thought we have over a hundred of them and never seen this problem. Well the first time it happened I looked like I knew what I was talking about . We now keep 3 x-tra boards in stock and get a bad one every month or so!!!

This was actually my first time seeing this as well. I had the 120vac on terminals 1 and 3. Guess I pulled the trigger to quick. I plan on repairing the board and keeping it as a spare. When you guys replace the boards, is the board specified for that model number? For example the board I have is from 72N model. Can I put this into a 72G or 72DV model?

with a core we get rebuilt boards from access elevator for about $100 so its hardly worth fixing yourself unless you do it at night in front of the TV. And yes one board fits all.

Wow, can you see me in my living room?

But ya, 9 times out of 10 it's just the logic board, although I have seen the IGBTs fail too. I keep 2 in my van and I have used both in a weekend. Over 90 volts from 1 to 3 and no display or a stuck or not closing up to speed contact = logic board.

HAHA yes yes I can. Do not worry your secrets are safe with me.!!!Please go to you tube and search Dirt on Dirt!!!!! HAAAAAA!

Just to close this thread...
If anyone decides to repair the logic card. The right capacitor and resistor value is below. part# is also included for easy reference.

Resistor Value(R58): 20ohm 3w
Manufacture: Vishay BC components
Part#: AC03000002009JAC00

Capacitor Value(C46): .033uF 450v
Manufacture: TDK Corp.
Part#: C3225C0G2W333J250AA

The capacitor shorts and takes out the resistor. I've heard of people snatching the capacitor off and just replacing the resistor.

Yes, thats what I have done many times. And I've never had that problem once the capacitor is removed. And I also repair the "Up to speed contact" shorted problem in the field.