Ashton Crusher wrote:
On Tue, 08 Feb 2011 17:37:18 -0600, bud--
wrote:

Jon Danniken wrote:
bud-- wrote:
A lot of people here work with electric motors - no one seems to know
what SPL is. Jon might but he isn't saying much.
The two local motor rewinders that I called yesterday told me it stood for
"special", as in it is a particular type of rating used in motors for
specific applications, namely compressors.
Much more appropriately I saw someone call it "Someone's Probably Lying".

I'm sure you could contact Magnetek/Century (the manufacturer of the motor
on my compressor) for a more specific answer.
Now apparently owned by AO Smith.
IMHO their website sucks. I looked earlier for info on SPL and couldn't
find anything, including no phone number.

I agree with everyone but Jon that it is an excuse to lie.
The only "lie" would be calling a 3HP SPL (15A/115V) motor a 3HP motor,
which may have been the case in the past with less than reputable merchants
such as Sears/Craftsman, among others. To some of the participants on this
newsgroup, that is an excuse to consider legitimate motor manufacturers
guilty of the same type of deception, even when they properly label their
products.
There was a class action lawsuit about 5 years ago about fraudulent HP
ratings on compressors/motors. The manufacturers lost and were supposed
to use real HP ratings. You have the old fraudulent rating hidden behind
"SPL". Your 3HP rating is a lie intended to deceive. The same as in
class action lawsuit (with a minor cover your ass).

gfretwell wrote "if it is 120v it will not be more than 1HP." He is
right. Yours works because it is not a 3HP motor. Because of past, and
apparently current, fraud about everyone here has said ignore HP ratings.

I believe the phrase "when all you've got is a hammer, everything looks like
a nail" is appropriate here.

Is there any reason why the "real" HP is not used?
How is a 3HP SPL motor different from a motor with a real HP rating?
What possible reason is there to use "SPL"?

I can think of one reason.
It is the same fraud as in the class action lawsuit about 5 years ago,
with a minor cover-your-ass.


I can think of another. It possible that there is some design
difference in how the motor is wound or some other aspect that makes
it more difficult for it to stall if someone shuts it off and then
immediately back on when it's pumping under high pressure.

Far as I know they all unload when the motor stops I wouldn't bet on
starting against high head pressure.

I think the answer is closer to what clare wrote. In looking around, the
motors I saw on compressors were capacitor start, capacitor run. Those
motors, in general, have relatively high starting torque and relatively
low starting current for that torque. I have seen no reason to believe
"special compressor motors" are anything but standard cap start, cap run
motors.

The problem I have is Jon's 3HP SPL motor. It is a scam rating. Just
like the scam ratings that resulted in the class action lawsuit, which
the manufacturers settled. If Jon knew it was not a real number then why
post it? (And then there was Jon's 2.3HP miscalculated value.)

A scam "peak" 3HP motor has a peak (near stall) torque that is equal to
the normal running torque of a 3HP motor. It is not the starting torque
of a 3HP motor.

For many of its smaller compressors, Grainger gives both the scam "peak"
HP (competitive with Jon's scam rating) and a real HP.

I haven't seen any reason to believe that the "real" HP is not the
appropriate rating. Because there are plenty of scam ratings, you can't
compare compressors based on HP rating (as many people here have said).
Even with real HP ratings you need to compare the air you need with what
a compressor provides (also as many people here have said).

=============
This is similar to joule ratings on surge suppressors. In that case
there is not a defined way to measure the joule rating. So some
manufacturers use deceptive ratings. As a result, some major
manufacturers no longer give a joule rating.

--
bud--