Compressor motor/starter swap wiring

[Cryptic1911]

We picked up a 5hp 80gal 2340n5-v 3ph ingersoll rand compressor a while back cheap and figured we would just throw another motor on it. I got a good deal on a 7.5hp 1ph motor and grabbed a cheap weg mag starter enclosure, but we’re not quite sure how the hell to rewire this thing. One thing I hadn’t considered is the pressure switch. Would I have to change that too? I’ve included some pics of what we are working with

 

[Cryptic1911]

 

[The Cobbler]

looks like your starter is only capable of a 3 hp motor to me.

 

[wyliesdiesels]

That starter will not work. It is rated for 3 hp at 115 V.

That 7 1/2 hp motor may not work for your pump either

While the pressure switch is rated for 208v 3phase, you should still be able to use it since its just switching one side of the starter coil

 

[Cryptic1911]

looks like your starter is only capable of a 3 hp motor to me.

Think thats for 120v. I have seem some places list it for 7.5, although I've seen a couple just now saying 5? Pretty sure it said 7.5hp 1ph when I picked it up though

 

[wyliesdiesels]

Think thats for 120v. I have seem some places list it for 7.5, although I've seen a couple just now saying 5? Pretty sure it said 7.5hp 1ph when I picked it up though

If the label on that cover is for the starter, then no its limited to 3HP @ 115v. Read the label again. Notice in the HP column it says 3?

 

[Cryptic1911]

oh I just noticed on the inside of the lid where it doesn't have voltages other than 120v listed, but this site says it will do 7.5 on 220 https://www.imc-direct.com/product_p/cwm40.htm

I was going off the cwm40 rather than the lid of the box

 

[Bert_]

The pressure switch just controls the coil. The little diagram on the lid that says two wire control shows how to wire it.

Look on the side of the contactor that's usually where the ratings are for IEC stuff. 3hp at 115 is probably 7.5 at 230v

 

[Terry D]

oh I just noticed on the inside of the lid where it doesn't have voltages other than 120v listed, but this site says it will do 7.5 on 220 https://www.imc-direct.com/product_p/cwm40.htm

I was going off the cwm40 rather than the lid of the box

Looks to me, according to your link, it is rated for 5 hp @ 230 volts

 

[Cryptic1911]

Looks to me, according to your link, it is rated for 5 hp @ 230 volts

Hm yeah looks like the page says 7.5, but if you click the link to the specs sheet it says 5 I can't remember where I got it, but it must have been mislabeled there as well Looks like a few other places list it that way too

 

[Cryptic1911]

Removed the cwm40 starter itself from the box to view the left side and its printed right there 120v 3hp / 240v 1ph 7.5hp, so I should be good. The original ad I found when I bought it specifically mentioned 7.5hp single phase. not sure why info is all over the place online.