Is there an inexpensive low tech alternative to home compressor soft starters?

[vanilla ice]

Is there an inexpensive low tech alternative to soft starters, that do not cost $300? I don't really need or want bluetooth features!

I figured somebody here would know the answer to this.

 

[dgc]

The 64 dollar questions, single phase, three phase, current loading and voltage. Amazon seem to do units costing silly money right down to realistic money.

 

[vanilla ice]

I have only two single phase compressors on 20 amp 110v circuits for the time being, but if you have three phase advice to share in the thread, post em if you got em.

What is the difference between the reduced inrush current kits for table saws? I assume those will not work with compressors. Anyway, what it is, is an older domicile with a window AC unit and fridge, that both flicker the lights. Maybe DIY is not the way to go for soft starters. Not knowing anything about them I figured I'd ask.

 

[fechter]

I've seen a setup where a solenoid valve opens to vent the compressor outlet when it's starting, then closes once the motor gets up to speed. There's still an inrush just getting the motor spinning, but much less than starting against pressure.
I would also assume a kit made for a table saw would work for a small compressor.

 

[rafalg]

The standard solution where I live is to use different type of circuit breakers in your electric system. Normal "B" type breakers, and overcurrent "C" type breakers where you have loads with big inrush current. C type breaker will tolerate a short period of overcurrent before tripping. Of course with the assumption that the rest of your wiring is able to handle the load.

 

[dgc]

Yep
"B" type breakers are a fast trip at around 3 to 5 times it's rated current usually for home use, "C" type breakers are a slow trip at 5 to 10 times it's rated current usually for commercial use. But as already mentioned make sure your wiring can take it, secondly a single phase time delay module is cheap and easy fit if you have an unloader valve on your compressor. I know my neighbors compressor has one fitter on his single phase compressor as I hear it load up once the motor is running. A delay module is about 10 dollars from Amazon.

With three phase star delta starters they start in star configuration to reduce the inrush current then automatically switching to a delta configuration once the motor reaches speed and one could put a time delay module on the delta contractor to then load the system up.

 

[vanilla ice]

Nothing is tripping yet, but the lighting in the older area flickers when either of the two small compressors kick on. I do have some electronics in that area I'd rather not damage. Figured I maybe should head off anything bad happening. Its a 1940's building, with some modern single and multi phase wiring. The compressor and flicker area is the older non updated wiring area.

The soft start kits intended for table saw use are the most inexpensive. They specifically say "for brushed motor use" which is what makes me suspicious of their compatibility with compressors.

www.amazon.com/Pre-Wiring-Accessory-Circular-Grinders-Machines/dp/B0DPP9F9M2

 

[Papa]

Its a 1940's building

Has the incoming service (from the pole, or underground to the main breaker panel) cabling been upgraded or replaced? What is Amp rating of the main (kill all) circuit breaker?

 

[dgc]

Yep, so the question is is the motor toy have brush-less or brushed.

 

[vanilla ice]

Building mostly upgraded to 2015 parts with a big honkin ten kilowatt EV charge port and a new main panel. The one section of the building with the flickering is the section not upgraded. Of course. The fridge is a 1980 unit so I doubt its brushless. The AC is a modern 2015 window unit so may be brushless? I don't know much about compressors. I looked around and see they make 12v mini splits now. I may just do a battery solar isolated 12v system for AC and get rid of the window unit. The electric bills around here are getting ridiculous when running AC.

Actually I take the part back about the 20a circuits, these circuits are so old, maybe they are 10 or 15 amp circuits. I have to look them over and see what they are. I'm wondering if this part of the building is wired as original or if they are like a 1970's upgrade. I will have a look. These days I will forget what I figured out the next day after I figure it out.. is the problem. At least I can post here and re-read what I wrote.

 

[TommyCat]

Once you verify that your electrical power supply is safe and adequate, and the units are not damaged.
(wire size/length, circuit breakers, connection and terminations. Amp draw per appliance within specs…)

The first thing that came to mind would be a hard start kit.

Example:
Hard Start Kit Super Boost SPP6 Relay & Hard Start Capacitor
and
https://www.supplyhouse.com/Supco-R...MIlNGW1_uelgMVq4DCCB3ZNxs6EAQYAyABEgLxkPD_BwE

Simple wiring and device that introduces a high capacity capacitor into the circuit for fast motor starts, then it automatically drops out of the circuit.
Has been known to reduce or possibly eliminate compressor start-up light dimming.
You must get the right kit size based on your units tonnage or horse power rating.

Read up on it and see what you think.
Finding the room for it may be the hardest part...


Regards,
T.C.

 

[vanilla ice]

Has the incoming service (from the pole, or underground to the main breaker panel) cabling been upgraded or replaced? What is Amp rating of the main (kill all) circuit breaker?

Yes, we built out from the back of the building to the pole. New main panel, more service, with permits and the works. I forget the exact numbers. The one outlet for the EV charge outlet is about the same power that the whole place used to be. Original building size was around 800 foot, now its more than twice that. Built to the limits of the local regulations. I wish we hadn't but we left the original wiring in that 800 foot area.

 

[OlderGiantFan]

You could attach a pull starter to it and take some of the load off that way