Soft Start question

[Glenn_And_Kitty]

I installed a briidea soft start on my Coleman-Mach A/C. After installation A/C came on I see a "green light" on the soft start unit which is supposed to mean it is working. Should the voltage change after the fan and then the compressor starts? Let me explain.
I take a voltage reading and it is 116 volts. I turn on A/C and voltage drops to 111 volts and stays there.
I was under the impression that the A/C fan would come on and drop voltage slightly and then the compressor would come on a short time after and drop the voltage a bit more.
I did not take any reading on voltage drop before I installed the unit so maybe a 5 volt drop is not that much and that is how a soft start works. It seems that the fan and compressor are coming on at the same time when I turn the A/C on.
Can anyone advise me.
Glenn

[pianotuna]

It takes 5 starts for the soft start to "learn". Do that on a GOOD power source.

[wa8yxm]

Nothing wrong with 111 The fact it's not going to like 105 or 100 means the soft start is working.

The fact it's drooping means the wiring (likely park side) is anemic.
The A/C draws around 13 amps running. that's what's drooping the voltage.
Normally it can draw a whole not more (And thus a much larger drop) Starting but the soft start is limiting that.

[Glenn_And_Kitty]

To prichardson: Yes, I am taking readings on the inside of my RV from a volt meter I have plugged into an outlet. It's not about the actual number but more about the amount of decrease in volts. Again I was expecting the fan to come on then the compressor but it seems like both are coming on at once. If it is only a 5 volt drop when both come on I'm assuming that is OK and the unit is doing what it is designed to do.

To 3 Tons: I will try your suggestions and give the unit some time to "learn" my A/C. the real test, and what I installed the unit for, is when I use my generator.

[3_tons]

I can’t say for certain, but I also have a Coleman Mach 1 P.S. with a ‘EasyStart’ soft-start, so a couple of observations:

First off, it’ll take several start and stop cycles for the soft-start ‘to learn’ how best to properly function…

Considering that the fan and compressor are starting-up and running simultaneously, 111v seems acceptable (108v is typically the lower design limit), and may have something to do with the power supply (especially summertime in a RV park!) or robustness of supply wiring, though I wouldn’t necessarily count this to be an item of primary concern - JMO…

On ours, I set the t-stat function switch so that the fan is on continuous LOW speed, while compressor has about a built-in 3 min start-up delay…This helps avoid the likelihood of concurrent dual motor starts, thereby reducing overall inductance (current surge)…

Hope this helps 🙂

3 tons

[prichardson]

Are you taking the readings in the RV or at the service connection? A voltage drop is normal when operating a high current device like an A/C. How much it drops will be affected by the quality of connections (ie plug & receptacle), voltage, and wire size. A start assist device only reduces the the current spike of the compressor start.