Need Warning before Compressor Starts to Prevent Cardiac Arrest

Thread Starter

KeefyW

Joined Feb 1, 2020
21
No. It doesn't have an operating system and the IDE runs on Windows. Be warned, it's buggy and the Arduino (and RPi) forums aren't very friendly. I gave both a try, both to learn and contribute, but found the environment to be hostile (mostly from very high post count members who are too full of themselves).
It's the same on most forums. That's why I'm reluctant to get involved, on the whole. You guys however seem quite nice and helpful. My neice got the crap bullied out of her on - get this - Mum's net !!! I had an electronic problem on my motorbike which I solved but never found the original cause of the problem. Went on to Yamaha forum to ask advice and got tons of meaningless crap from people who obviously didn't understand my question but were 4- or 5-figure contributors. Get the ratings up but don't actually help anyone. If you're interested in the problem I had, from an electronic pov, go here:
http://foc-u.co.uk/index.php?topic=25860.msg308085#msg308085

or for a preview of all posts:

http://foc-u.co.uk/index.php?action=profile;area=showposts;u=12819

Cheers :cool:
 
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drc_567

Joined Dec 29, 2008
1,093
There is a device called a soft start module. The primary purpose is to limit the start-up inrush current to the electric motor. However, it would likely affect the initial complaint of an abrupt noise. The devices appear to have delay options, depending on the particular model. ... Relatively simple installation. ... You might inquire at a local air conditioning or industrial supply store.
 

djsfantasi

Joined Apr 11, 2010
7,633
No. It doesn't have an operating system and the IDE runs on Windows. Be warned, it's buggy and the Arduino (and RPi) forums aren't very friendly. I gave both a try, both to learn and contribute, but found the environment to be hostile (mostly from very high post count members who are too full of themselves).
But not everyone has the same experience. I found the Arduino forum friendly and helpful. And I’ve yet to find a bug in the IDE. The IDE is free and just about anything you need to do is addressed by it.

Programming is done in a variant of C+. And the language is powerful. Arduino is more than a microprocessor. It is a complete system. Built-in features include PWM, digital input/output, analog input. And there are many peripherals available (Arduino calls them shields). Music players, SD card file storage, motor control, hobby servo control, voltage and current sensors... And development boards for designing your own peripherals.

And the IDE can be used to program a wide range of Arduino systems (Uno, Mega, Nano) as well as standalone chips (ATTiny series).
 

dl324

Joined Mar 30, 2015
12,798
You guys however seem quite nice and helpful.
I got trolled on this site by several high post count members when I first joined, but moderation intervened and I stayed. This site has an ignore member feature which also helps. When I asked if such a feature existed on the Arduino and RPi forums, the high post count members started trolling me.
 

Thread Starter

KeefyW

Joined Feb 1, 2020
21
There is a device called a soft start module. The primary purpose is to limit the start-up inrush current to the electric motor. However, it would likely affect the initial complaint of an abrupt noise. The devices appear to have delay options, depending on the particular model. ... Relatively simple installation. ... You might inquire at a local air conditioning or industrial supply store.
Will look into that. Many thanks..
 

Thread Starter

KeefyW

Joined Feb 1, 2020
21
I got trolled on this site by several high post count members when I first joined, but moderation intervened and I stayed. This site has an ignore member feature which also helps. When I asked if such a feature existed on the Arduino and RPi forums, the high post count members started trolling me.
That's the internet for you ! Don't mention brexit or you will surely be trolled to within an inch of your life !!!!!
:eek:
 

Thread Starter

KeefyW

Joined Feb 1, 2020
21
There is a device called a soft start module. The primary purpose is to limit the start-up inrush current to the electric motor. However, it would likely affect the initial complaint of an abrupt noise. The devices appear to have delay options, depending on the particular model. ... Relatively simple installation. ... You might inquire at a local air conditioning or industrial supply store.
OK You have it !!! No audible warning necessary. It will start softly. That's all I want. My table saw and skill saw do the same. Nothing too shocking to the aged auditory flaps. Module cheaper than time delay thingy. Perfect. Thanks.

Can you imagine being in your own little world pottering round the workshop listening to the radio when, with no warning a 95dB compressor starts up at full chat. I can tell you it makes you jump and you don't get used to it. Trust me.

I guess you can close this thread now.

Sorry Ron. Thanks again to all.
 

MaxHeadRoom

Joined Jul 18, 2013
22,857
OK You have it !!! No audible warning necessary. It will start softly. That's all I want. My table saw and skill saw do the same. Nothing too shocking to the aged auditory flaps. Module cheaper than time delay thingy. Perfect. Thanks.
Be aware that most compressors start loaded, which means they require a very high starting torque, if you are reducing the torque at start up, you could see problems
Your table saw and skill saw (Universal motor) do not start under load generally, also the universal motor is not an induction motor .
Those that fit VFD's to 1ph motors often see drop out of run when loaded.
Just something to be prepared for.
Max.
 

drc_567

Joined Dec 29, 2008
1,093
... Just a thought ... When the compressor sfarts, the interna! pressure should be at the minimum setting, not the maximum. That being said MHR's comment about a load at start-up is a valid point, so you will have to try it out and see if it works.
Let the forum know when you have a chance.
... regards to wife and cats.
 

Papabravo

Joined Feb 24, 2006
15,783
I'm skeptical on the claim that sudden loud sounds can trigger an MI (Myocardial Infarction), especially if you are free of other risk factors. Do you have any evidence on this or is it just your opinion or feeling that: "it must be true". I might believe that a factory work subjected to loud noise for an entire 8 hour shift from a punch press might have a higher risk, but I think a compressor is unlikely to be a significant causal factor.

What I think is that smoking, eating, weight, exercise, stress, and cholesterol should be under control before you worry about flyspecks in the pepper.
 
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MaxHeadRoom

Joined Jul 18, 2013
22,857
... Just a thought ... When the compressor sfarts, the interna! pressure should be at the minimum setting, not the maximum.
Some compressors that start under high load are fitted with unloaders, for this reason.
My shop compressor starts from where the P.S. re-restarts the motor, <80lbs. NO unloader.
Max,
 

Thread Starter

KeefyW

Joined Feb 1, 2020
21
Be aware that most compressors start loaded, which means they require a very high starting torque, if you are reducing the torque at start up, you could see problems
Your table saw and skill saw (Universal motor) do not start under load generally, also the universal motor is not an induction motor .
Those that fit VFD's to 1ph motors often see drop out of run when loaded.
Just something to be prepared for.
Max.
True. Saws start with 0 load. Maybe I'll go back to the delay option... beep beep beep. Shame. Soft start seemed ideal. What do you think of this ? Not my idea but is for a fridge compressor which presumably also starts on load. Go here https://www.homemade-circuits.com/motor-soft-start-circuit-for/

Comments gratefully received.
 

Thread Starter

KeefyW

Joined Feb 1, 2020
21
I'm skeptical on the claim that sudden loud sounds can trigger an MI (Myocardial Infarction), especially if you are free of other risk factors. Do you have any evidence on this or is it just your opinion or feeling that: "it must be true".
I have history of cardiovascular events but was not entirely serious, nonetheless. I am not daft enough to think that a mild shock could trigger an MI either. Just a sense of the melodramatic with a touch of (optional) humour. Humour - Nanu Nanu...
 

MaxHeadRoom

Joined Jul 18, 2013
22,857
As the article is titled, Home made Electrical Projects! :rolleyes:

As one can see from the extract of the text, they are sending pulsating DC to the motor, just at a time when maximum torque is required!
A start cap is just that, its job is to supply current for the start period when the motor needs it most.
I personally would be very leery of applying this mod to my fridge!

"QUOTE: Refrigerators tend to draw appreciable amounts of current each time their compressor switch ON, and this could happen many times per day.
The capacitor in a capacitor start motor has nothing to do with the speed of the motor.
The capacitor is there just to energize the field coil of the motor for helping the main winding to start the rotation, after which it's cut-of from the system.

.As soon as the internal relay of the refrigerator clicks ON, diode D1 provides a half wave AC to the refrigerator forcing a slow soft start to the motor,
the SCR is unable to conduct immediately due to the the presence of the capacitor at its gate.
Therefore at the start, the refrigerator is able to get only a half wave AC through the rectifier diode, until the capacitor across the SCR gate/cathode charges up and fires the SCR.
During this period the half wave AC allows only around 50% of initial voltage to the refrigerator, providing a soft start to the motor, until within seconds the SCRs fires and restores full available power to the motor.
Once the SCR is fired it takes on the other half of the AC so that the refrigerator motor is able to gain its full rated torque."
 

Thread Starter

KeefyW

Joined Feb 1, 2020
21
... Just a thought ... When the compressor sfarts, the interna! pressure should be at the minimum setting, not the maximum. That being said MHR's comment about a load at start-up is a valid point, so you will have to try it out and see if it works.
Let the forum know when you have a chance.
... regards to wife and cats.
My wife, Dennis's cats !!! :)
I will tinker and get back to you. At the moment stat is set so pump runs at 80 psi and cuts at 115 psi. My wife's tools like 60 - 80psi so all is groovy. See another post for a suggestion for modulating fridge compressors. Interesting ? Let me know what you think. Thanks
 

Thread Starter

KeefyW

Joined Feb 1, 2020
21
As the article is titled, Home made Electrical Projects! :rolleyes:

As one can see from the extract of the text, they are sending pulsating DC to the motor, just at a time when maximum torque is required!
A start cap is just that, its job is to supply current for the start period when the motor needs it most.
I personally would be very leery of applying this mod to my fridge!
Thank you Sir. Very valid arguement against this idea. However in their defence and mine, I am a Home made kind of bloke. I think I will go for the beep/delay method.
 

K OBrien

Joined Nov 28, 2020
14
I would consider using a solenoid powered three way air valve to unload the compressor on startup. Like a Trimantec https://cdn.shopify.com/s/files/1/0068/3235/7429/files/Airtac-3V2_Trimantec.pdf Common port to the compressor, normally open port to outside air and normally closed to the tank. Then put the solenoid coil in series with a time delay, connect across the line after the motor contactor. Like the ICM controls ICM102 delay on make time delay. https://www.icmcontrols.com/documents/LII032-1ICM102Instruction.pdf Your compressor should start unloaded pushig air out the valve until after the time delay then it should begin sending air to the tank.
 
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