Capacitor Replacing ?

[Johnch]

One of the guys I goose hunt with needed to use a trailer
So He is using mine
He was going to sort of rent mine , but I agreed to not charge him LOL

His dad just passed away and he is starting to clean out the house and barn
As the last few years he threw away NOTHING
So he got a dumpster for the junk and will use my trailer to haul home a few things

His dad used to work in a machine shop
At home he had a Milling machine and a lathe at least
My friend is not sure what is still in the barn as it is stuffed full of bags of trash

But I could see part of a older milling machine covered with a tarp
Under a pile of cardboard boxes
My friend told me he used it 2 or so years back
But last time he wanted to use it his dad told him one of the capacitors needed replacing

Long story short
I bought it and any tooling for it for $100
IF the lathe is still there , I can get it and all the tooling for it also

But first he will have to spend a week or 2 filling the dumpster with trash

I have a capacitor tester
But it has been 12 years since I worked on any wiring for larger electric motors
Every spring we would get a number of service calls on pump stations for field drain tile pumps
My former boss would just want us to replace a bad capacitor and leave the others alone
Not sure if this was the best way

I am guessing at least 1 of the capacitors will need replaced
But should I just replace them all when I get to see if one is really is bad ?

Thanks
John

[lancem]

They are cheap considering you probably won't ever have to replace them again. I would look to see what size is needed, order them, replace them and then forget about them.

[rancher1913]

we always powered the tool up then unhooked the capacitors and tossed them to the new guys, if they cought it and let out a howl we new it was good.

[country gent]

I would replace the bad capacitor and go with it. One thing with the mill and lathe is make sure they arnt 3 phase not a big deal the new phase invertors arnt super expensive but they also cost power and life on the motor.

I have an inverter on my bridgeport with no issues so far and run a 5 hp rotary converter on my lathe and the will also be used on the frill press when it gets here.

[Johnch]

I would replace the bad capacitor and go with it. One thing with the mill and lathe is make sure they arnt 3 phase not a big deal the new phase invertors arnt super expensive but they also cost power and life on the motor.


Not a problem
I have 200 AMP 3 Phase service at the barn where I will be using what ever I get
As I had to have 3 Phase for the Field tile pumps next to the barn

John

[farmbif]

I would only replace what is bad. I salvage capacitors from junk motors every chance I get. the ones on water pumps and the like usually 130-250 mf start capacitors are very common but when they get to larger sizes sometimes they are not so easy to find. seems baldor uses completely different sizes than marathon on for example 5hp 1760 rpm. motor.
if the milling machine has capacitors on the main motor up top thats kind of unique if it is a full size milling machine to have a single phase motor.
great find and great deal not matter what kind of mill it is for $100.

[john.k]

Best to check it out ........his dads opinion of whats wrong may not be accurate........obviously ,as you have 3 phase,you know to check the data plate on the motor before connecting it up......in general ,3 phase motors do not have capacitors ,single phase motors do.

[Scrounge]

They are cheap considering you probably won't ever have to replace them again. I would look to see what size is needed, order them, replace them and then forget about them.

What he said!

[ebb]

Replace them all, I have a Powermatic table saw I bought new in the late 80s. It is on its third capacitor now and I find that when I need it , waiting to get it fixed is a real pain. Do everything you can to make it run for ever.

[BLAHUT]

Replace them all and put the good used ones away for later if needed.

[popper]

caught it and let out a howl we new it was good.
Best way to test. Replace them all.

[megasupermagnum]

Most multimeters have a function to measure capacitance. Test them, replace only the bad one. I'm not sure why anyone would do it any other way. There is also a chance none (there should only be 1 or 2) of them are bad.

[GregLaROCHE]

Best to check it out ........his dads opinion of whats wrong may not be accurate........obviously ,as you have 3 phase,you know to check the data plate on the motor before connecting it up......in general ,3 phase motors do not have capacitors ,single phase motors do.

I always thought that 3 phase didn’t need capacitors. Only single phase. I’m not an electrician, but that’s just what I’ve come to believe over the years.

[MaryB]

Capacitors dry out with age and change value. Replace them all, it will help the life of the motor. If it is a capacitor in a digital read out then definitely replace them all!