Compressor high pressure setting?

[Tyler]

So I'm trying to find the last few accessories to get blasting, and today I called a buddy that works at a paint store that specializes in autobody stuffs. I was needing a water trap/filter. Everything I have found so far at the BORG's is either not a fine enough filter (my regulator wants a 5 micron in front of it) or the max pressure is too low. So I'm thinking my buddy will have what I need. We get to talking about pressure rating, and he suggested something that has me scratching my head. He says he'd set the upper end of the pressure of the compressor to 150psi instead of the 175psi it's rated for. He said the cost in heat and electricity to get to the max pressure isn't worth it, law of diminishing returns.

My compressor doesn't slow down as it approaches max pressure but I'm sure the current draw must increase some as the load increases. Seems that the lower high end would mean more cycling, and isn't the start up spike an expensive part of running an electric motor? Obviously, I'm skeptical, but what do I know?

Thoughts?

[baweaverpipes]

Tyler,
When we blast, a lot of air is used to blow the media. Other applications like painting, tools, filling tires, require very little compared to sandblasting @ 115psi.
It would be cycling like crazy to keep up if you lowered to 150.
But, what do I know? Rod Davies should chime in since, I hate to admit, he is the resident expert.

[KurtHuhn]

It would cycle less often, but as you approach max pressure the current that the motor is drawing increases drastically. At the same time a crapload of heat is getting generated inside the windings of the motor, and when it kicks off that heat sits there with no fan running to help dissipate it - and risk of burning the insulation off the windings increases.

Start windings do draw a lot of power, but only momentarily. They also generate a lot of heat, but again, only momentarily - and once the compressor motor is running, the fan is cooling the start windings off.

It's really a tradeoff - less cycling while blasting, or more wear and tear on the motor.

[Tyler]

Thanks guys.

My 3 pipes a year doesn't matter a hill of beans either way, so I guess this is just an exercise in curiosity.

Another factor, I suppose, is how much punch the motor has? In other words, if the high end of the pressure never actually challenges the motor that much, then going to 175 might not be into diminishing returns yet. The motor on my compressor is huge. It's silly big compared to the "5 HP" motors on the Home Depot units. I think my motor is 5HP, but I'm not sure. There's not a plate on it. I look at it though, and the motors on similarly rated compressors, and it just doesn't seem like mine should be stressed.

I need to borrow a meter that measure current, and watch the compressor cycle. Be interesting to see the curve as it approaches shut off.

...or I could just start blasting.

(There's a reason I only get three pipes a year done, I guess.).

Tyler

[Sasquatch]

Is this you, Tyler?

http://www.youtube.com/watch?v=bnqtXOi1iaY

[RadDavis]

I now how to blast a pipe. I don't know nothin' about cycling or reducing max pressures or nothin' like that.

Rad

[SimeonTurner]

I now how to blast a pipe. I don't know nothin' about cycling or reducing max pressures or nothin' like that.

Rad

Rad also doesn't know how to spell "know," apparently.

[RadDavis]

I now how to blast a pipe. I don't know nothin' about cycling or reducing max pressures or nothin' like that.

Rad

Rad also doesn't know how to spell "know," apparently.

I ment to do that.

Rad

[e Markle]

I now how to blast a pipe. I don't know nothin' about cycling or reducing max pressures or nothin' like that.

Rad

Rad also doesn't know how to spell "know," apparently.

I ment to do that.

Rad

It's "mint" M-I-N-T, "mint".

Hoap this helpes