correct capacitor for 110v 3.5 hp motor: need help

[Jvvmusme]

i need to calculate the correct capacitors (run and start) for a compressor that has a motor of 3.5 hp at 110v. i need also the electronic centrifugal switch

thanks in advance

 

[Jvvmusme]

i need to calculate the corrects capacitors for a 110v 3.5 hp motor
thanks

 

[wyliesdiesels]

Gonna need more info

What is the brand and model#?

Isthere existing caps?

 

[Norcal]

It's related to this thread. https://www.garagejournal.com/forum/showthread.php?t=383497&showall=1

 

[Jvvmusme]

Gonna need more info

What is the brand and model#?

Isthere existing caps?

Type: ML 901-2
Kw: 2.5
H.P. : 3.5
V: 120
A: 27
Ins.CL: F
IP: 55


Hz: 60
S: SI
R/min: 3480
80 MF 250v
600 MF 150v

Able Electric Co.

 

[Jvvmusme]

Gonna need more info

What is the brand and model#?

Isthere existing caps?

Yes plus centrifugal switch

 

[Jvvmusme]

Photo of capacitirs


QUOTE=Jvvmusme;7324002]Type: ML 901-2
Kw: 2.5
H.P. : 3.5
V: 120
A: 27
Ins.CL: F
IP: 55


Hz: 60
S: SI
R/min: 3480
80 MF 250v
600 MF 150v

Able Electric Co.[/QUOTE]

 

[alfredeneuman]

Hz: 60
S: SI
R/min: 3480
80 MF 250v
600 MF 150v

 

[Jvvmusme]

Hz: 60
S: SI
R/min: 3480
80 MF 250v
600 MF 150v

those are the ones I have and the motor will not start properly.

it worked fine the first time I connected to the wall. after I disconnected the motor and tried it again the motor will not work anymore. every time it will trickle the breaker or show a message of motor overload in the screen

breaker of 40 amps, 8 gauge cable.

 

[AA7483]

Those are some big caps. Did you test them?

 

[James-W]

I don't understand the problem. The data plate gives the capacitor values. You have the capacitors that tell you the value. If one or both of the capacitors are bad then replace them with the same value capacitors. Why do you need to calculate what they should be?

 

[walta]

Please measure the supply voltage when the motor is off and again when the motor is trying to start.

The motor is labeled for 120V your post say you are supplying 110V if this is the case you may need a buck boost transformer to get the correct voltage.

Walta

 

[walta]

I do not read Chinese but you may have the wrong centrifugal switch as yours is labeled 220V this photo shows 120V model.

Walta

 

[Jvvmusme]

I do not read Chinese but you may have the wrong centrifugal switch as yours is labeled 220V this photo shows 120V model.

Walta

you know where I can get these in the USA ?

thanks

 

[DenisG]

From other thread:

https://www.garagejournal.com/forum/showthread.php?t=383497&showall=1

jyxg 03-08

from jycapacitors.com

3hp

110v
60 hz
1 phase

116 psi (8 bar)
12 cfm

150 liter tank
electronic control unit

i had a buying agent visit the factory, research its reputation, send me an owners and operation manual . the operation and owners manual has no typing or spelling mistakes !!!! in perfect english .... no chinoenglish....

they agreed on 110 volts,1 phase

$ 700 dlls fob shangai. I ordered 12 units for a 12 friends buying group. I should have them in Colombia by june 15. I will report when received....

Hard to believe that a perfectly written manual from a reputable company would not have included requirements for installation and installation instructions.

This is not a good advertisement for this product.

 

[walta]

This is from china but it looks like you could buy 1 at a time.

http://renaissance.en.makeronly.com...al-switch-201611051423331651934144659395.html


the DMS05U looks like it should work to me.
http://www.isovolt.com/

Walta

 

[Worsedog]

I do not read Chinese but you may have the wrong centrifugal switch as yours is labeled 220V this photo shows 120V model.

Walta

you know where I can get these in the USA ?

thanks

That is not a centrifugal switch. It is a motor brake rectifier.

While it is certainly possible that you have defective parts in your new compressor, firing the parts cannon is not helping here.

Go back to basics and verify that you have the proper supply voltage and enough current to start the motor. If your supply voltage was too low earlier when you ran the compressor damage could have been done that is causing the problems you are experiencing now.

 

[American Locomotive]

That is not a centrifugal switch. It is a motor brake rectifier.

While it is certainly possible that you have defective parts in your new compressor, firing the parts cannon is not helping here.

It is a "centrifugal switch". Some websites poorly translate it as "motor brake rectifier". I've noticed that more and more Asian-made electrics motors are doing away with mechanical centrifugal switches. They now often utilize electronic "centrifugal" switches. It just monitors the motor's speed electronically, and then switches out the start winding once it hits a certain speed.

If he's got a 230v rated switch, he will certainly need the 120v one.

 

[Jvvmusme]

Problem solved.

An empirical compressor guy arrived with like 20 capacitors and started playing around until he got the right combination.

it tok him like 4 hurs.

40 amps breaker and 8 gauge cable

 

[Jvvmusme]

first of all its my fault. I should never had ordered 3.5 hp motors with 110 volts. They should had being 220v 1 phase as the factory had them . So my stuborness in ordering 110v is my fault.

I finally changed the starting capacitor from 600mF 150 vac to the new one of 300mF 250 vac and everything works perfect on all 12 compressors.