more power from motor

Status
Not open for further replies.
junkhound

junkhound

Senior Member
Location
Renton, WA
Occupation
EE, power electronics specialty
yes, from a 5HP (rated) motor

yes, from a 5HP (rated) motor

please note the line in the previous post ....

It draws 48 A/240V now at 10 HP (48A includes the 1/3 HP blower motor); need to run a 6 AWG feeder if I go up to 8 gpm

Thus, the 5 HP motor is now operating with a 10 HP output with the added blower. 8 GPM at 4 ksi would be about 20 HP. Have run this for a few years 6 - times a year for 5-8 hours at a time, no failures yet.

Per another comment: yes, I expect I'd need to have a few pump seal repair kits on hand if run at 3540 or so RPM.


carry on from there......
 
renosteinke

renosteinke

Senior Member
Location
NE Arkansas
There just happens to be a fellow at another forum who uses the same screen name. Now, this is the internet, and you can't trademark a screen name- so we have no reason to believe our junior member is the bomb-tossing loose cannon guy at the other place.

More educated folks will quickly recognize that the OP's post makes a few assumptions that are not correct.

He assumes all 5hp motors are the same. That's simply not true. Even within the same manufacturer, there are plenty of completely different motors of a given size, each designed for a particular use. That's why you don't use just any motor for an elevator- to use one example. An ordinary motor is not designed to stand up to the short cycling of an elevator. That's just one example.

Put a fan on it? Sure. How about ... use a motor that already has a fan? I'm looking at a 20hp motor as I type, and it's considerably larger than a TEFC 5hp motor across the aisle.

Can you get 20hp out of a 5hp motor? Look at the LRA for the motor. Do the math. No you know whether the motor will choke before you get to 20hp. How long can you get 20hp? At least until you let the smoke out. Short bursts? Insulation damage is accumulative, so you might want to keep a megger log.

What do RPM's have to do with anything? Horsepower is horsepower .... (Well, sort of, as there's a lot of lying motor labels out there!), Changing RPM influences torque, but not horsepower.

Basic science teaches that a valid experiment has only one variable. The OP proposes to change at least two separate things: cooling and RPM. With two variables, the experiment cannot have a valid conclusion- even if a particular arrangement works.

Don't feed trolls.
 
Status
Not open for further replies.
Top