dual voltage motor issue

[BRT]

if it's on a tank, just time it to fill the tank. i.e. an 80g tank is 10.69cf, 100psi=6.9bar, so 74cf at 100psi. Time how long it takes to get there and you get cfm.
If it's a true 3hp motor though, it should be doing 10-12cfm though. That said, you can't run a 3hp motor on a normal wall outlet since the amp draw is going to be close to double what a normal wall circuit can do, so there is that to consider.
17.6a on 120v is around 3hp, but that means the motor is consuming about 3hp, not making about 3hp which is irritating. Realistically it means it will be around 60% efficient, so making around 1.8hp maybe 2? Either way that should still be around 8cfm.

If the motor is turning properly and it the compressor RPM is to spec, then any drop in CFM is going to be due to leaks somewhere. Usually in the valves.

Better recheck your math.

 

[tbone1004]

Better recheck your math.

what'd I miss? running around like mad today

 

[BRT]

what'd I miss? running around like mad today

Maybe I'm missing something. You usually have it right. 74cf at 100psi?

 

[tbone1004]

Maybe I'm missing something. You usually have it right. 74cf at 100psi?

low pressure air compressor, was talking about an 80g air tank. If it holds 80g of water, then it would hold 74cf of gas at 100psi

 

[NAM001]

So I picked up another shop compressor to run my booster. I has a 3hp 120/240V motor on it. Unfortunately the wiring sticker is worn away so I can't tell if it's jumpered for 120v or jumpered for 240v. The 4 terminals are not labelled at all. How can I tell these apart with a multimeter?

(it has 2 capacitors on top if it matters)

View attachment 587591

someone help me here. in a motor you have 4 winding leads. call them A B C D for 220 B anc C at connected to gether 220 is connfected to A and D leaving 120 on each winding becazuse they are in series.. when wiring for 120 you will see 2 pairs of leads connected to each other A and C is one pair and B and D ois the other pair. that makes them in parrelel leaving 120 vac on each coil again. if the wires have not been disturbed when connected to a source if 120 there will be 3 wires tied to gether for line and 3 more wires for neutral. So with out lables you can look at eh wiring and make a pretty good guess. otherwise with loose ends you have to find teh pair that has wome resistance to it and then the other pair with resistance to it and those will be the 2 coils.


240vac - A ____OOOOOO---------- B C -----------0000000000 -------------- D 240 opposite phase the Os are the coils they are in series


120 line A ____________000000000000000----------------- B to neutral
| |
| |
C ------------------ 000000000000000-------------- D

 

[rjack321]

someone help me here. in a motor you have 4 winding leads. call them A B C D for 220 B anc C at connected to gether 220 is connfected to A and D leaving 120 on each winding becazuse they are in series.. when wiring for 120 you will see 2 pairs of leads connected to each other A and C is one pair and B and D ois the other pair. that makes them in parrelel leaving 120 vac on each coil again. if the wires have not been disturbed when connected to a source if 120 there will be 3 wires tied to gether for line and 3 more wires for neutral. So with out lables you can look at eh wiring and make a pretty good guess. otherwise with loose ends you have to find teh pair that has wome resistance to it and then the other pair with resistance to it and those will be the 2 coils.


240vac - A ____OOOOOO---------- B C -----------0000000000 -------------- D 240 opposite phase the Os are the coils they are in series


120 line A ____________000000000000000----------------- B to neutral
| |
| |
C ------------------ 000000000000000-------------- D

There is no way to see any other this, its all in the case.

 

[rjack321]

low pressure air compressor, was talking about an 80g air tank. If it holds 80g of water, then it would hold 74cf of gas at 100psi

yes 2.6cf tank x 6.7 atm = 72cf

Mine is only 20gal though, so 18cf @ 100psi.

 

[BRT]

low pressure air compressor, was talking about an 80g air tank. If it holds 80g of water, then it would hold 74cf of gas at 100psi

Ahhh, all this time I was thinking scuba compressor.

 

[NAM001]

There is no way to see any other this, its all in the case.

if there are wires exposed you should be able to multimeter it out to see if its wired for 120 or 240.

 

[rjack321]

if there are wires exposed you should be able to multimeter it out to see if its wired for 120 or 240.

120V and it runs