Soft Starters for motors ,Fridges etc.

[mike95490]

You need more battery, or a higher battery voltage. 12 & 24 v systems have huge DC surges with starting motors which gives voltage sag before the inverter.
Super Caps are wrong idea, just another expensive component needing a big expensive fuse for when they expire.

That said, i used a simple timer on my freezer for 2 years till i upped my PV capacity . Manual defrost only, frost free systems often initiate a defrost cycle at power up.

 

[ed1380]

there's already caps inside inverters. you're just supersizing them. is it worth it? no

 

[squowse]

Yes.

The ones that have more detail seem to say that they only do the soft start either when triggered by the separate control wire, or when voltage is first applied. The situation with the fridge is that it's sitting on standby drawing small current then a surge when the compressor is switched on. I would need one that could see that surge and mute it.

 

[mike95490]

Another trick that can sometimes work, is a long 100' extension cord, laid out so no hot spots develop in use. The extra resistance helps limit the starting surge, and the running power will not suffer.

 

[houseofancients]

I've got a few of these and they work surprisingly well. Not sure if they have them for US voltage.

would they work for a 3 kw air to water heatpump.?

 

[upnorthandpersonal]

Should do with the SSR-100WA-R1 or higher. Of course, I don't have the details on your system and I assume you're in Europe or similar and not the States (this soft-started in particular are 230V single phase).

 

[Hedges]

English translation of that page says,

"This product has often been used for motors with the following voltages:

220V ... (50Hz, 60Hz).
230V ... (50Hz, 60Hz).
240V ... (50Hz, 60Hz
The above three voltages are universal for this product."

Whether application is 230V single phase or 115/230V split phase shouldn't matter. The circuit elements in the soft-starter would be isolated from ground.

50 vs 60 Hz would differ a bit. Inductor impedance is proportional to frequency and capacitor is inversely proportional. So the ideal values would differ (like one intended for a different HP motor) but the steps in HP between models is fairly large.

It seems like this product adds a capacitor in series with starting windings according to a time delay and/or voltage developed.
Others with a relay and capacitor engage/disengage based on voltage division between capacitor/winding being sufficient to operate the relay.
Diagrams for connecting this unit don't show what's inside. For others, I've seen an additional capacitor paralleled with the motor's capacitor.

 

[TRW]

This is all very interesting, but I have a few questions, but not sure what they are yet!

 

[Bossrox]

Digital Timer for Lamps & Appliances

Amazing deals on this Digital Lamp & Appliance Timer at Harbor Freight. Quality tools & low prices.

www.harborfreight.com

These are great timers, I use a bunch of them.

 

[Supervstech]

Youtuber great Scott has some diy videos making a soft start.
It slowly increases the voltage to get motors to slowly ramp up rpm.

 

[TRW]

Youtuber great Scott has some diy videos making a soft start.
It slowly increases the voltage to get motors to slowly ramp up rpm.

I am not sure of the rules, but can you post a link to a soft starter for a motor like most of us might want to use? What I found at this site was not applicable to starting a two or three horse power compressor for example.

 

[Supervstech]

 

[TRW]

I am not trying to be funny, but this seems to be a soft start system that needs a soft start system. (The start surge on it causes the need for a soft start) I am done commenting on this, but I don't see it as a solution for our real world problem. I understand the theory of the device, but I am having a hard time understanding how this can help in an application that we are looking for.

 

[Supervstech]

I am not trying to be funny, but this seems to be a soft start system that needs a soft start system. (The start surge on it causes the need for a soft start) I am done commenting on this, but I don't see it as a solution for our real world problem. I understand the theory of the device, but I am having a hard time understanding how this can help in an application that we are looking for.

How so? Maybe I misunderstand?

 

[TRW]

How so? Maybe I misunderstand?

I don't think this device will be a helpful solution to the problem in question. With many of these situations, we will only know for sure unless someone tries it. I watched the entire video, and came to the conclusion that it a has very minimal advantage and will be more of a detriment to the user than and advantage. The device itself consumes power. Again I could be wrong and I don't intend to comment more on it. I do hope others weigh in on it.

 

[Supervstech]

Whelp, that sounds like a challenge.
I see the gadget as a voltage dimmer timer, controlled by programming to slowly increase voltage, preventing surges from motors starting up.

I don’t have a clue what most of the parts he listed in the schematic are, but I guess I will get them and build it to see how well it works.

Not sure why @TRW has issues with it... I don’t see a double soft start ... he seems to be dead set against discussing it, so, I will start ordering parts... I might hit my old electronics boss up and see if he has the parts.

 

[TRW]

Great attitude, good luck with your build!

 

[squowse]

Can anyone give me advice on how to setup this cheap Chinese soft start? Or if I'm doing something wrong?

It's the 1kW version.


500W Victron Phoenix Inverter powering 100W (when running) fridge. The inverter starts the fridge fine but makes a bit of a load buzz for about half a second each time the fridge compressor starts.

With the soft start in line I am getting 700W draw until I switch it all off. Is that it charging a capacitor or something? I'm a bit low on battery charge so not keen for an extended experiment at this moment. I was hoping to have reduced current flowing obviously.

There are two controls. One for the voltage ramp up time 0-30 seconds. And the other is the bottom of the voltage ramp (I think). 0 to 50%.
I've tried them in various positions including both on minimum and it doesn't seem to make much difference to the power drawn.

 

[upnorthandpersonal]

With the soft start in line I am getting 700W draw until I switch it all off.

That sounds very strange. I'll check some stuff on mine...

 

[-sgt-]

A big capacitor right on the inverter lugs

Video shown lesser voltage drop with capacitor...