In my shop I run a 5HP Ingersol Rand 2 stage compressor. The first
motor lasted just a little longer than the warranty, but until it let
the magic smoke out it started the compressor every single time. I had
an extended warranty so eventually when the service company got tired of
lying to me and lying to the warranty company I eventually got a new
motor. Not the same motor (thank goodness), but also not the same frame
size motor.

(In the interim I ran a cheap motor I bought on-line.)

The interim motor would trip its thermal protector all the time. Drove
me bonkers. The new motor I eventually got also trips its thermal
protector, but not as often. The trip is just about always on startup.
The unloader appears to be operating correctly.

All of the motors are/were single phase induction motors with a great
big pair of caps on them. (run and start caps) In my research into the
original crappy motor from Ingersol Rand (reviews were insanely bad
including claims of bursting into flame) a couple people recommended
installing a soft start kit on the motor or any replacement motor.

Anybody have a soft start for dummies guide they can point me to that
might be appropriate for this application?

I also considered a reduced pulley size to reduce load on the motor, but
then the motor would run longer each time it cycled on. I don't know
what the balance of heat build up would be from longer run, verses less
load. Compressor duty motors are not intended to run continuously.

I also considered a 3 phase motor with a VFD and a soft start programmed
into the VFD, but 5HP 3 phase motors aren't cheap and neither are VFDs
big enough to drive them on single phase.

If this thing exploded tomorrow I'd be tempted to go back to the 3.7 HP
compressors I ran before, and just plan to repair them every couple years.

--
Bob La Londe
CNC Molds N Stuff

--
This email has been checked for viruses by AVG antivirus software.
www.avg.com

"Bob La Londe" wrote in message news:ug4hq7$1cjmf$1@dont-email.me...

In my shop I run a 5HP Ingersol Rand 2 stage compressor. The first
motor lasted just a little longer than the warranty, but until it let
the magic smoke out it started the compressor every single time.

-------------------------

I put this PZEM-061 on my mongrel 80 gallon compressor to observe and
compare the current draw to the motor's rating, to match the motor pulley to
a replacement compressor pump.

https://tinyurl.com/yhjfzcxc

"Bob La Londe" wrote in message news:ug4hq7$1cjmf$1@dont-email.me...

Might your unloader have failed and be forcing the motor to start against
pressure?

My 1/2HP compressor wouldn't start from a 3KW generator until I modified a
blowoff valve into a manual lever controlled unloader. The genny won't start
my ancient Maytag unless I push the spring-loaded motor inward to loosen the
belt.

On Tue, 10 Oct 2023 19:03:44 -0400
"Jim Wilkins" <muratlanne@gmail.com> wrote:

>"Bob La Londe" wrote in message news:ug4hq7$1cjmf$1@dont-email.me...
>
>In my shop I run a 5HP Ingersol Rand 2 stage compressor. The first
>motor lasted just a little longer than the warranty, but until it let
>the magic smoke out it started the compressor every single time.
>
>-------------------------
>
>I put this PZEM-061 on my mongrel 80 gallon compressor to observe and
>compare the current draw to the motor's rating, to match the motor pulley to
>a replacement compressor pump.
>
>https://tinyurl.com/yhjfzcxc
>

Would that be able to show if there was a significant voltage sag
while it was trying to start? Transient events like that (lasting just
seconds) can be hard to spot...

--
Leon Fisk
Grand Rapids MI

On Tue, 10 Oct 2023 15:04:55 -0700, Bob La Londe <none@none.com99>
wrote:

>In my shop I run a 5HP Ingersol Rand 2 stage compressor. The first
>motor lasted just a little longer than the warranty, but until it let
>the magic smoke out it started the compressor every single time. I had
>an extended warranty so eventually when the service company got tired of
>lying to me and lying to the warranty company I eventually got a new
>motor. Not the same motor (thank goodness), but also not the same frame
>size motor.
>
>(In the interim I ran a cheap motor I bought on-line.)
>
>The interim motor would trip its thermal protector all the time. Drove
>me bonkers. The new motor I eventually got also trips its thermal
>protector, but not as often. The trip is just about always on startup.
>The unloader appears to be operating correctly.
>
>All of the motors are/were single phase induction motors with a great
>big pair of caps on them. (run and start caps) In my research into the
>original crappy motor from Ingersol Rand (reviews were insanely bad
>including claims of bursting into flame) a couple people recommended
>installing a soft start kit on the motor or any replacement motor.
>
>Anybody have a soft start for dummies guide they can point me to that
>might be appropriate for this application?
>
>I also considered a reduced pulley size to reduce load on the motor, but
>then the motor would run longer each time it cycled on. I don't know
>what the balance of heat build up would be from longer run, verses less
>load. Compressor duty motors are not intended to run continuously.
>
>I also considered a 3 phase motor with a VFD and a soft start programmed
>into the VFD, but 5HP 3 phase motors aren't cheap and neither are VFDs
>big enough to drive them on single phase.
>
>If this thing exploded tomorrow I'd be tempted to go back to the 3.7 HP
>compressors I ran before, and just plan to repair them every couple years.

It sure sounds like the motor is a tad too small for the task. And/or
needs the pulley system to run the pump slower for a given motor
speed.

Joe Gwinn

"Leon Fisk" wrote in message news:ug65ef$1qtoh$1@dont-email.me...

On Tue, 10 Oct 2023 19:03:44 -0400
"Jim Wilkins" <muratlanne@gmail.com> wrote:
>PZEM-061

Would that be able to show if there was a significant voltage sag
while it was trying to start? Transient events like that (lasting just
seconds) can be hard to spot...
Leon Fisk

-------------------------
They aren't as fast or good as analog meters for detecting glitches, but
they will indicate high circuit resistance that could cause a voltage sag by
the current and voltage drop when running. One reason is that the changing
digital display isn't as noticeable in your peripheral vision as a sudden
needle jump. I leave an analog Amprobe on troublesome old motors to show
when the start switch has stuck open. The PZEM-061 like is a 240V, 100A
Kill-A-Watt. Installing one in an electrical box cover is a good test of
layout and filing skills. I'll just say that I've gotten better at it.

A voltage sag is more a symptom of a problem in your supply circuit.
Although it takes more test equipment I prefer to monitor the current draw
to tell if something is operating normally or has a problem.

My UT61E DVM supposedly can capture peak transients but its readings of them
don't relate well to oscilloscope captures. My datalogger uses it and other
RS232-output DVMs as sensors and won't capture events shorter than a second.

The best I have to capture current spikes on a scope is a Hantek Hall effect
probe for DC and a Fluke current clamp for AC. They were fairly inexpensive
and good enough for hobby use such as measuring refrigerator starting
surges, to select a large enough inverter.

On 10/11/2023 8:00 AM, Joe Gwinn wrote:
> On Tue, 10 Oct 2023 15:04:55 -0700, Bob La Londe <none@none.com99>
> wrote:
>
>> In my shop I run a 5HP Ingersol Rand 2 stage compressor. The first
>> motor lasted just a little longer than the warranty, but until it let
>> the magic smoke out it started the compressor every single time. I had
>> an extended warranty so eventually when the service company got tired of
>> lying to me and lying to the warranty company I eventually got a new
>> motor. Not the same motor (thank goodness), but also not the same frame
>> size motor.
>>
>> (In the interim I ran a cheap motor I bought on-line.)
>>
>> The interim motor would trip its thermal protector all the time. Drove
>> me bonkers. The new motor I eventually got also trips its thermal
>> protector, but not as often. The trip is just about always on startup.
>> The unloader appears to be operating correctly.
>>
>> All of the motors are/were single phase induction motors with a great
>> big pair of caps on them. (run and start caps) In my research into the
>> original crappy motor from Ingersol Rand (reviews were insanely bad
>> including claims of bursting into flame) a couple people recommended
>> installing a soft start kit on the motor or any replacement motor.
>>
>> Anybody have a soft start for dummies guide they can point me to that
>> might be appropriate for this application?
>>
>> I also considered a reduced pulley size to reduce load on the motor, but
>> then the motor would run longer each time it cycled on. I don't know
>> what the balance of heat build up would be from longer run, verses less
>> load. Compressor duty motors are not intended to run continuously.
>>
>> I also considered a 3 phase motor with a VFD and a soft start programmed
>> into the VFD, but 5HP 3 phase motors aren't cheap and neither are VFDs
>> big enough to drive them on single phase.
>>
>> If this thing exploded tomorrow I'd be tempted to go back to the 3.7 HP
>> compressors I ran before, and just plan to repair them every couple years.
>
> It sure sounds like the motor is a tad too small for the task. And/or
> needs the pulley system to run the pump slower for a given motor
> speed.
>
> Joe Gwinn

I assure you its very unlikely I will ever buy another IR compressor.

--
Bob La Londe
CNC Molds N Stuff

--
This email has been checked for viruses by AVG antivirus software.
www.avg.com

On Wed, 11 Oct 2023 13:10:53 -0400
"Jim Wilkins" <muratlanne@gmail.com> wrote:

<snip>
>The best I have to capture current spikes on a scope is a Hantek Hall effect
>probe for DC and a Fluke current clamp for AC. They were fairly inexpensive
>and good enough for hobby use such as measuring refrigerator starting
>surges, to select a large enough inverter.

Thanks, good info👍

Analog meters were still widely used when I started working. Switched
to a digital (bought my own) a few years in. The analog meter
spike/twitch was sorely missing. Maybe 10 years later I bought a Fluke
87 which had the bottom bar in the display that updated 4x? faster than
the digital display. Was quirky but helpful once you got used to it...

--
Leon Fisk
Grand Rapids MI

On Wed, 11 Oct 2023 14:02:43 -0400, Leon Fisk <lfiskgr@gmail.invalid>
wrote:

>On Wed, 11 Oct 2023 13:10:53 -0400
>"Jim Wilkins" <muratlanne@gmail.com> wrote:
>
><snip>
>>The best I have to capture current spikes on a scope is a Hantek Hall effect
>>probe for DC and a Fluke current clamp for AC. They were fairly inexpensive
>>and good enough for hobby use such as measuring refrigerator starting
>>surges, to select a large enough inverter.
>
>Thanks, good info?
>
>Analog meters were still widely used when I started working. Switched
>to a digital (bought my own) a few years in. The analog meter
>spike/twitch was sorely missing. Maybe 10 years later I bought a Fluke
>87 which had the bottom bar in the display that updated 4x? faster than
>the digital display. Was quirky but helpful once you got used to it...

My compressor motor was originally wired for 115 and it kicked out on
start-up about hnalf the time when cold and about 10% of the time when
warm. I switched it over to 230 and it hasn't had a single issue
since. I even put a bigger pulley on it after converting to 230. My
original motor was a repulsion start monster(with brishes) but the
start switch went bad and parts were unobtanium so I switched to the
cap-start

"Bob La Londe" wrote in message news:ug4hq7$1cjmf$1@dont-email.me...

In my shop I run a 5HP Ingersol Rand 2 stage compressor. The first
motor lasted just a little longer than the warranty, but until it let
the magic smoke out it started the compressor every single time.

--------------------------

Here is a better controlled alternative to a mechanical unloader. It might
reduce the starting surge enough to make the motor last much longer.
https://tameson.com/pages/compressor-unloader-valves

Their indirect valve operates like the water valves on a lawn sprinkler
system. It does the same thing as my manual cammed-open pressure relief
valve, lets the motor start without a load. A mechanical unloader releases
the air between the compressor head and the tank check valve when the
pressure sensing diaphragm in the control unit rises to shut off the motor,
but the head outlet pipe's volume is low and the unloader vent valve closes
when the diaphragm drops and pressure builds again on the first piston
upstroke. A timed unloader can vent the air until the motor reach full
speed.

I think you could add one in parallel with the mechanical unloader, the
compressor won't build pressure until both unloaders have stopped venting.

Today at the ham radio flea market I picked up and examined a 1-10 second
time delay relay of the type I had used in industrial relay logic
controllers in the 70's. The seller explained using it to time a solenoid
valve unloader on a compressor, which suggests he had seen it done. I was
just trying to remember if I already had one like it. I built a 240V
spotwelder timer with another one that I set to 0.2 seconds for 22 gauge
galvanized steel.

On Fri, 13 Oct 2023 20:09:49 -0400, "Jim Wilkins"
<muratlanne@gmail.com> wrote:

>
>
>"Bob La Londe" wrote in message news:ug4hq7$1cjmf$1@dont-email.me...
>
>In my shop I run a 5HP Ingersol Rand 2 stage compressor. The first
>motor lasted just a little longer than the warranty, but until it let
>the magic smoke out it started the compressor every single time.
>
>--------------------------
>
>Here is a better controlled alternative to a mechanical unloader. It might
>reduce the starting surge enough to make the motor last much longer.
>https://tameson.com/pages/compressor-unloader-valves
>
>Their indirect valve operates like the water valves on a lawn sprinkler
>system. It does the same thing as my manual cammed-open pressure relief
>valve, lets the motor start without a load. A mechanical unloader releases
>the air between the compressor head and the tank check valve when the
>pressure sensing diaphragm in the control unit rises to shut off the motor,
>but the head outlet pipe's volume is low and the unloader vent valve closes
>when the diaphragm drops and pressure builds again on the first piston
>upstroke. A timed unloader can vent the air until the motor reach full
>speed.
>
>I think you could add one in parallel with the mechanical unloader, the
>compressor won't build pressure until both unloaders have stopped venting.
>
>Today at the ham radio flea market I picked up and examined a 1-10 second
>time delay relay of the type I had used in industrial relay logic
>controllers in the 70's. The seller explained using it to time a solenoid
>valve unloader on a compressor, which suggests he had seen it done. I was
>just trying to remember if I already had one like it. I built a 240V
>spotwelder timer with another one that I set to 0.2 seconds for 22 gauge
>galvanized steel.
>
>
My solution was to increase the volume of the line between the outlet
of the compressor and the check valve at the inlet to the tank,
providedof course, that this line is de-pressurized when the motor is
awitched off.

"Gerry" wrote in message news:ho1kiihvrqktcle5poqdiad9p5862i5ir9@4ax.com...

My solution was to increase the volume of the line between the outlet
of the compressor and the check valve at the inlet to the tank,
providedof course, that this line is de-pressurized when the motor is
awitched off.

--------------------

I did that too, by adding a loop of Parker Push-Lok air hose that won't
degrade from vibration as unsupported copper tubing might. My HF compressor
pump has a built-in air cooler attached to the head, that adds some volume.

I think the best approach is to capture and compare the motor starting surge
with a digital storage scope and current clamp, both as-is and with the
compressor outlet disconnected to simulate a timed unloader.

"Bob La Londe" wrote in message news:ug6n6v$1v4l2$1@dont-email.me...

>> Anybody have a soft start for dummies guide they can point me to that
>> might be appropriate for this application?

---------------------------

I've been investigating soft start options and mainly found $200-$300
commercial units and much cheaper DIY solutions that require knowledge,
construction and test equipment. It seems the common requirement is reducing
the air pump starting load so I posted what I found about that. Reducing the
motor start current is a separate issue that might be solved or helped with
an unloader.

Bob La Londe <none@none.com99> wrote:
> In my shop I run a 5HP Ingersol Rand 2 stage compressor. The first
> motor lasted just a little longer than the warranty, but until it let
> the magic smoke out it started the compressor every single time. I had
> an extended warranty so eventually when the service company got tired of
> lying to me and lying to the warranty company I eventually got a new
> motor. Not the same motor (thank goodness), but also not the same frame
> size motor.
>
> (In the interim I ran a cheap motor I bought on-line.)
>
> The interim motor would trip its thermal protector all the time. Drove
> me bonkers. The new motor I eventually got also trips its thermal
> protector, but not as often. The trip is just about always on startup.
> The unloader appears to be operating correctly.
>
> All of the motors are/were single phase induction motors with a great
> big pair of caps on them. (run and start caps) In my research into the
> original crappy motor from Ingersol Rand (reviews were insanely bad
> including claims of bursting into flame) a couple people recommended
> installing a soft start kit on the motor or any replacement motor.
>
> Anybody have a soft start for dummies guide they can point me to that
> might be appropriate for this application?
>
> I also considered a reduced pulley size to reduce load on the motor, but
> then the motor would run longer each time it cycled on. I don't know
> what the balance of heat build up would be from longer run, verses less
> load. Compressor duty motors are not intended to run continuously.
>
> I also considered a 3 phase motor with a VFD and a soft start programmed
> into the VFD, but 5HP 3 phase motors aren't cheap and neither are VFDs
> big enough to drive them on single phase.

like everybody else says reduce the pulley. Your line voltage may also be
too low. A three phase motor at 5hp should cost less than 1 single phase
one as no other junk like starters or capacitors are needed. The do make
soft starters for 3 phase motors at under $100. They mess with the power
going to one phase, but it works. The starter coils on single phase motors
draw a ton of power and could be the overheating cause if you're
constantly starting and stopping that motor. 3 phase motors don't have
this issue at all.

On Wednesday, October 11, 2023 at 2:52:23 PM UTC-7, Clare Snyder wrote:
> On Wed, 11 Oct 2023 14:02:43 -0400, Leon Fisk <lfi...@gmail.invalid>
> wrote:
> >On Wed, 11 Oct 2023 13:10:53 -0400
> >"Jim Wilkins" <murat...@gmail.com> wrote:
> >
> ><snip>
> >>The best I have to capture current spikes on a scope is a Hantek Hall effect
> >>probe for DC and a Fluke current clamp for AC. They were fairly inexpensive
> >>and good enough for hobby use such as measuring refrigerator starting
> >>surges, to select a large enough inverter.
....
> My compressor motor was originally wired for 115 and it kicked out on
> start-up about hnalf the time when cold and about 10% of the time when
> warm. I switched it over to 230 and it hasn't had a single issue
> since. I even put a bigger pulley on it after converting to 230. My
> original motor was a repulsion start monster(with brishes) but the
> start switch went bad and parts were unobtanium so I switched to the
> cap-start

This reminds me that motor startup is critically dependent on the AC wiring
gage; that '230' conversion using similar gage wiring has less resistive power
loss at any given load than the 120V connection, because the
higher voltage uses less current. A long, not very heavy, wiring
connection from the breaker box to the socket that motor plugs into, would
have the overheats-at-start effect, even on a properly designed motor
and compressor with working unloader.

If you get overheating during starts, suspect the wall wiring.