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bmw625
06-29-2015, 11:18 PM
not a wizard with motors, advice please. 1 hp baldor motor powering a simplex hydraulic pump for press. have not used it a lot,but no problems until today. started bending a piece of mild steel, when suddenly breaker trips, motor stops. reset breaker (20 amp) does it again. tried outlet on different breaker, same thing. motor plate says 7-8 amps (115) motor was HOT to the touch. (can't hold hand on it )

http://www.tksimplex.com/html/product_detail.php?pid=644&catname=Hydraulic%20Power%20Pumps&scatname=G%20Series%20Pump%20Platform

if link works, it is similar to the pump shown,but with solenoid valve. thoughts?

thanks,bmw

Bob Ford
06-29-2015, 11:47 PM
Is your start switch sticking closed. You should hear a click as the motor slows to a stop. If not pull the end bell and look for burnt welded contacts on the switch.

Bob

J Tiers
06-29-2015, 11:47 PM
Sounds like the pump got blocked, or otherwise won't turn, and motor stalled.

Or maybe the motor failed.

Stuck start switch could do that too, but is hard to find without disassembly or having the motor actually start.

You need to see if the motor will work when driving the pump free flow, or when not driving the pump at all (disconnected manually). That should indicate if the motor is any good.

be aware that the motor windings could have shorted to ground and so the case could be live if you take it off the pump assembly.

It is likely to be a positive displacement pump, and so if flow is blocked, the pump will be blocked, and that will stall the motor. Was it a bigger piece than usually bent?

I notice it is a cap start motor, which makes it a little easier to find a bad start switch.

bmw625
06-30-2015, 07:55 PM
I didn't look at it after work tonight -- too tired - actually a smaller piece than what I usually work with. I will have to pull the pressure hose off, try that, proceed from there I guess.
thanks for the advice, I will post what I find in a day or so. bmw

Doozer
06-30-2015, 09:20 PM
+1 on stuck start switch or a blocked pump dragging rpm
down into start mode.

-D

bmw625
07-04-2015, 11:36 AM
haven't disconnected the pump from motor yet,but did pull the assembly off of the reservoir. motor seems to be running at normal speed, no funny noise, ran approx. 15 seconds,tripped breaker. later today I will start dis-assembly of motor, I guess.
bmw

lakeside53
07-04-2015, 12:10 PM
Look for a stuck relief valve on the pump.

As for "normal speed"... even a few % slip of the rated speed (load in excess of the rating) will cause an over-current situation.

bmw625
07-04-2015, 12:56 PM
I am leaning towards switch-- it has tripped while running pump,(pressurizing cylinder) , while not pressurizing cylinder, and with pump out of reservoir (no oil in pump) there is a small switch/relay ? in line from the on/off toggle has 4 wires some go into the motor housing. wonder what it is/does?
bmw

J Tiers
07-04-2015, 03:01 PM
I am leaning towards switch-- it has tripped while running pump,(pressurizing cylinder) , while not pressurizing cylinder, and with pump out of reservoir (no oil in pump) there is a small switch/relay ? in line from the on/off toggle has 4 wires some go into the motor housing. wonder what it is/does?
bmw

Which switch?

When the start cycle is over the switch should open. EASY way to find out......

Get your clamp-on meter, any kind so long as it will show the current you have, although an analog meter with a needle is best. Clamp it on a mains wire. Start motor.

If the start switch is working, motor will start, and the current will spike up, come down, and then suddenly drop to maybe 1/3 of what it was. If switch is not working , the current will stabilize at a higher level, and you will not see a sudden drop.

MaxHeadRoom
07-04-2015, 03:41 PM
I am leaning towards switch-- it has tripped while running pump,(pressurizing cylinder) , while not pressurizing cylinder, and with pump out of reservoir (no oil in pump) there is a small switch/relay ? in line from the on/off toggle has 4 wires some go into the motor housing. wonder what it is/does?
bmw

Your motor may be fitted with a external Potential relay instead of internal centrifugal sw.
It senses voltage across the start winding and cuts out the capacitor.
Max.

bmw625
07-04-2015, 05:50 PM
Your motor may be fitted with a external Potential relay instead of internal centrifugal sw.
It senses voltage across the start winding and cuts out the capacitor.
Max.

could this relay fail and cause breaker to trip?

MaxHeadRoom
07-04-2015, 06:27 PM
Two causes, if the motor is overloaded and the relay does not drop out due to not coming up to speed, or the contacts are welded/remain closed.
Max.

bmw625
07-04-2015, 08:48 PM
if what I think is the "relay" is actually a relay (4 wires ,spade connected , one from power) it got hot in the short time it took to trip breaker.
bmw

PStechPaul
07-04-2015, 10:33 PM
That sounds like a motor overload relay which has a thermal current element which gets hot and causes it to trip after a delay. If properly sized, it should trip before the breaker, but if the motor is close to the rating of the breaker, it may trip first, because it has a shorter delay.

http://electrical-engineering-portal.com/thermal-overload-motor-relay-protection
http://electrical-engineering-portal.com/working-principle-of-thermal-motor-protection-relay

http://thumbs1.ebaystatic.com/d/l225/m/m5AUuB2bYwPWhPVS_RN5Cdw.jpg http://thumbs3.ebaystatic.com/d/l225/m/mJCN3OW5NJC8rIaG8pUPipw.jpg http://thumbs4.ebaystatic.com/d/l225/m/mUdyiAdoP4oAgBkWQ0YALBQ.jpg

The relay itself is usually part of a motor starter, which also includes a contactor that actually opens and closes the power to the motor.

bmw625
07-04-2015, 11:51 PM
this is the motor http://www.baldor.com/catalog/JL3509A at least most of the numbers match my motor. the small box on mine has a smaller box attached,holding the "relay"
bmw

MaxHeadRoom
07-05-2015, 10:06 AM
According to the schematic it is a 3 winding motor and has an internal Centrifugal SW as well as external thermal/current (relay) switch.
Max.

bmw625
07-05-2015, 01:24 PM
I assume the centrifugal switch is at one end of the motor? which end usually ?
bmw

danlb
07-05-2015, 02:09 PM
The switch is usually on the end opposite the shaft. There's a cover that comes off with relative ease.

Dan

bmw625
07-05-2015, 04:33 PM
took end off motor. there is no switch on end of shaft. looked at youtube to make sure I knew what a cent. switch looked like.

bmw

MaxHeadRoom
07-05-2015, 04:38 PM
Just going by the PDF on the motor part No. You gave.
If you don't have a C.F. switch then it sounds as though you have the single potential relay only externally.
Max.

bmw625
07-06-2015, 01:46 PM
apparently I have a "sinpac " switch need to investigate further
bmw

bmw625
07-06-2015, 02:32 PM
multi-meter test across 2&3 supposed to be 500k or more. with multi meter at 2000k setting, it shows 000 ??
bmw

MaxHeadRoom
07-06-2015, 02:40 PM
at 2000k setting, it shows 000 ??
bmw

If infinity (open) that may be correct for 500k min, if 0 ohms then it is shorted.
Synpac looks like a SS potential relay, http://www.torq.com/pdffiles/cat-sinpac.pdf
https://docs.google.com/viewer?url=http%3A%2F%2Fstearns.rexnord.com%2Fpdf% 2FCat_902%2F22-25.pdf
Max.

bmw625
07-06-2015, 04:01 PM
I guess the "000" is infinity ? the test pdf says infinity is ok. I don't know what next to check, the motor starts fine, runs about the same amount of time before it trips the breaker.
bmw

MaxHeadRoom
07-06-2015, 04:13 PM
What you need to do is try and detect if there is any start winding current when the motor comes up to speed, you could do this by measuring the voltage across the start cap, if there is constant voltage or does not drop to zero then it would indicate the potential relay is bad possibly as long as the motor appears to come up to normal rpm.
Max.

PStechPaul
07-06-2015, 04:40 PM
A reading of 000 would not be infinity. It should probably show a 1 and blank, the same as you see with the leads disconnected. There could be a resistor across the capacitor or contacts but if so it's probably 10k or more and should show up on the 2000k range. Seems to be shorted or very leaky.

bmw625
07-06-2015, 05:07 PM
test link http://www.google.com/url?sa=t&rct=j&q=&esrc=s&source=web&cd=1&ved=0CB4QFjAA&url=http%3A%2F%2Fstearns.rexnord.com%2Fpdf%2FCat_9 02%2F28.pdf&ei=BO2aVfzOHMa0yATi35sI&usg=AFQjCNFl3mM7tvY61dITr_MPqK3bl6d1Jg&bvm=bv.96952980,d.aWw&cad=rja

when the multi meter is set to ohms, it shows 000 when I touch the leads together(continuity) it shows the same through the relay, if I test between the other terminals on the switch (not in the test instructions) it shows 804 ?

MaxHeadRoom
07-06-2015, 05:13 PM
Between 2 & 3 it should be open circuit.
Max.

bmw625
07-06-2015, 05:19 PM
so no continuity between 2&3 ? bmw

MaxHeadRoom
07-06-2015, 09:19 PM
See the PDF, disconnect from motor before trying.
Max.

bmw625
07-06-2015, 11:00 PM
I took it off of motor before I tested -- you could not see the terminal # s with it attached
bmw

bmw625
07-06-2015, 11:07 PM
my understanding of electrical is very basic - I know the multi meter shows continuity when it shows 0.00 or 000. the 20,200, 20k, 2000k settings I really don't understand - I am not an electrical guy - just a truck driver !!
bmw

Rosco-P
07-07-2015, 09:36 AM
my understanding of electrical is very basic - I know the multi meter shows continuity when it shows 0.00 or 000. the 20,200, 20k, 2000k settings I really don't understand - I am not an electrical guy - just a truck driver !!
bmw

https://www.youtube.com/watch?v=GpmrVgOaDGY

bmw625
07-07-2015, 02:42 PM
now the next challenge - where to buy just one sinpac switch - so far online not looking promising ! bmw