Ingersoll Rand problems

[Daz2012]

Got the possibility of buying a 4hp 1400rpm 4-pole 3-phase motor .

What else would I need to use this ? I know I'll need a starter,what else ?

 

[tigler]

The correct pulley and you are good to go.

 

[Daz2012]

Shenion said "You would have to change the pressure switch with a 3-phase contactor."

What's that ?
Do you know the formula for working out pulley sizes ?

 

[shenion]

A 3-phase contactor has three contacts to switch all 3 lines. Single-phase has two.

I'm not familiar with starters for 3-phase and I have never needed one. Some starters may include a contactor.

A fo pulley sizes, take the size and RPM of the existing motor. Change the pulley by the inverse ratio of the motor speeds. If the new motor is half the old one then use a pulley twice as big.

 

[tigler]

The pressure switch can be wired to operate the contactor relay, so a 3 phase one is not required.

 

[Daz2012]

That's assuming I had the right size pulley in the 1st place.
What rpm should the type 30 run at ?

 

[tigler]

As far as I can determine for your model T30, 820 RPM. So the motor drive pulley needs to be 1.70 times smaller than the pump pulley.

 

[Daz2012]

Thanks

 

[Daz2012]

I bought that motor so I'l let you know how it pans out

 

[tigler]

Don't forget, with a 3 phase motor it can run in either direction, so when it's installed make sure it runs in the correction direction for the pump, if it doesn't swap 2 motor wires (phases) around.

 

[eil]

Remember to get the appropriate overload for your contactor as well, you don't want to be frying your new motor now do you.

 

[Daz2012]

Got it running today,seems ok,I'll give it a good test this week.

I see there's another thread just started with the same pump wanting to use a single phase 3hp motor,well I used a 4" pulley (the diameter is actually measured overall not to the 'v') and we know how that turned out lol

I'm using an 8" pulley now and the pump seems to be turning at a higher rpm than before.I'm thinking the 3hp motor I was using wasn't actually powerful enough to drive the pump at the correct speed.

It's something for the other poster to consider before he uses a 3hp single phase motor to drive that big pump

Oh and thanks to everyone who offered advice on this thread

 

[Daz2012]

Final update,compressor is working great and the fill up from empty has come down from 4mins 30secs to 3mins 40 so I'm a happy chappy

 

[tigler]

Nice one ! Lets have some pix then ?!

 

[Daz2012]

Nice one ! Lets have some pix then ?!

It's no beauty queen

 

[eil]

Glad to hear you have got it going and you are happy with it, so 4hp motor and 8" pulley you used then, means you have more cfm and should last you quite a while if you don't neglect it too much, ugly queens need some love too you know

 

[Daz2012]

I'll keep her well oiled don't you worry lol

 

[Daz2012]

Told you she was no beauty queen lol

 

[tigler]

She's lovely !! Regular oil changes and keep that air filter clean.