Motor replacement advice

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The IntelliFlo might be a good choice for you.

For IntelliFlo, you will need to make sure that the wiring is at least #12 AWG for wire runs up to 100 feet and #10 AWG for lengths longer than 100 feet.

I’m still concerned about the voltage drop at the motor. You can get an inexpensive clamp on amp meter to check the amps.

I think that the voltage drop is going to be either the motor drawing too much amps or a problem with the wiring.

I wouldn’t put on a new IntelliFlo if there is a chance that the wiring has an issue. I would suggest getting a new breaker. I would suggest Pentair part Number PA220GF (2 pole 20 amp GFC) if it will work in your box.

I would suggest having an electrician replace the breaker, add a surge protector and check the wiring.

Then, once the power is correct and verified, add the IntelliFlo.

In your first post, you say that the motor is only 2 to 3 years old. It should not have failed this fast. I suspect that the power supply might be the cause of it not working.

The main reason I suggested having the motor checked was not to repair it, but to determine if it was the cause of the voltage drop.

If the motor checked out ok, then it would definitely point to a power supply issue.

A diagnostic fee should not be too much. How much did they want for a diagnostic fee?
 
JamesW said:
The IntelliFlo might be a good choice for you.
Click to expand...
I pulled the trigger on the Intelliflo

JamesW said:
For IntelliFlo, you will need to make sure that the wiring is at least #12 AWG for wire runs up to 100 feet and #10 AWG for lengths longer than 100 feet.
Click to expand...

I'm probably about at 100 feet as the junction box is on the opposite side of the house.

JamesW said:
I think that the voltage drop is going to be either the motor drawing too much amps or a problem with the wiring.
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I can buy a clamp meter. What would I be looking for that would tell me if it was the wiring or the motor? A surge in the Amp would suggest it is the motor? Wouldn't that trip the breaker?

JamesW said:
I suspect that the power supply might be the cause of it not working. The main reason I suggested having the motor checked was not to repair it, but to determine if it was the cause of the voltage drop.
Click to expand...

JamesW said:
If the motor checked out ok, then it would definitely point to a power supply issue.
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If it is the power supply and not the motor, I don't understand why it would suddenly start failing. Also, it would run dry fine but not under load (priming the basket). Wouldn't that point to it being a motor issue?

JamesW said:
A diagnostic fee should not be too much. How much did they want for a diagnostic fee?
Click to expand...

He didn't quote me a diagnostic fee. But he said something to the effect that it would take an hour of time just to check it out on the bench, plus any time to service it. You're easily looking at several hours at $125/hr. I can get you a new motor for $400, so it doesn't make much sense to try and repair it.

From what he said I'm guessing they would charge $125 to check it out.

Unfortunately, there only seems to be 2 electric motor repair shops in San Diego and the other one only does commercial/industrial.
 
I'm not sure but I suspect that there could be something about the power supply that might be causing the motor problems.

Maybe corrosion on the connections somewhere. Maybe where the breaker makes contact with the bus bar. I'm not an electrician or on site. Just trying to help you figure it out.

Maybe it's just the motor. I don't know. As the motor increases load, the voltage drops.

The voltage drop depends on load in amps and resistance of the wiring. High amps could be from a bad motor. High resistance could be from bad wiring or a bad connection somewhere.

I think that it will be pulling excessive amps if the wiring is bad or if the motor is bad. So that might not tell us anything.

When you install the IntelliFlo, make sure that the voltage is good before turn on and under load.

I would recommend having an electrician check the breaker and wiring before installing the Intelliflo to make sure that it's good.
 
If the wiring was installed correctly, there should not be more than a 5% voltage drop at full circuit load (20 amps).

You're getting about double that at 10 amps which indicates that the wiring has about 4 times the resistance (impedance) than it should. (Assumes full rated amps of motor. Since the breaker is not tripping, the load should not be more than 20 amps). Even if the motor was pulling close to 20 amps, the wiring has about double the impedance than it should.

In my opinion, that points to a wiring issue.

Note: I'm not an electrician or electrical engineer. Maybe I'm incorrect about my analysis.

I do think that it's worthwhile to get it checked by an electrician.

What can happen on the power supply side is a connection point can corrode over time slowly increasing resistance. This causes voltage drop and voltage drop causes increased amp draw.

Corroded contact points heat up and can cause a fire in some cases.
 
I checked the voltage at the breaker when the motor turns on and there was a small dip but nothing significant (239V to 233V).
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I don't know that that's insignificant. A 6 volt drop right at the breaker seems high. That's 1/2 your allowable drop right at the breaker.

There's basically no run at all. If the wire goes from the breaker directly to the pump with no connections along the way, I suspect that the problem is corrosion where the breaker meets the bus bars.
 
JamesW, These are all great suggestions and your points are well taken. I definitely want to get to the bottom of it before putting my new motor in.

I think I will be calling an electrician but I want to do as much detective work as I can to understand what has happened and what needs to be fixed.

Here is some information that might help:
My current motor is listed at 10Amps / 1.6SF or 16max amps. 230V

[I have no doubt now that the motor was getting less than 230V at least initially and maybe triggering an internal cutoff. But my question(s) 1). wouldn't this only happen at max speed? I would think the motor would still run on low speed unless the draw when the motor starts initially is the same. 2) Why now? The motor has worked well for months (presumably years). What changed?]

I estimate my wire run to be at 150 feet.
The wire is 12AWG at the breakers. Next to the pool it junctions with a switch box, an old mechanical timer, and then the motor. (I will have to check that the wire remains 12AWG for those portions)

According to voltage calculators with a 150 foot run and 12AWG:
Voltage drop: 9.53
Voltage drop percentage: 7.94%
Voltage at the end: 110.47

According to voltage calculators with a 150 foot run and 10AWG:
Voltage drop: 5.99
Voltage drop percentage: 4.99%
Voltage at the end: 114.01

So at this length, even with 10AWG, the motor may be getting less than 230V!

I bought a new breaker and I can swap that out but I realized I might be able to troubleshoot a little more (once it stops raining here).
I have a booster motor for the spa. It is not the same motor or pump and it bypasses the DE filter. But it is (or should be) 230V running on parallel lines to the Quadplex breaker.
I could measure the voltage and amp draw on it on the current lines and also when connected to the lines of my failed motor/pump.

I actually put a whole house surge suppressor in my Amazon cart but I didn't buy it because I realized it required it's own dedicated breakers. Unfortunately, this is a 35 year old house with a 100A circuit limited panel which is already maxed out. Many, possibly too many, of the breakers are already tandems to get around the lack of breaker space.

My plan to get solar electric panels are currently stalled because of the panel limitations. My options presented by the solar company are:
1) Retrench, to upgrade the panel. (but the power company won't do this in the current panel location. The panel was originally installed next to the gas lines and that is no longer allowed by code)
2) Derate the panel to add an RMA (Now I am afraid that doing this will cause me more problems with my pool electrical issues).

I wonder if adding a subpanel closer to the pool would alleviate the problem? It would certainly fix the voltage drop but I would still have to upgrade the main panel to support the subpanel.
Any way you cut it I see some major electrical costs in my future....
 
The old motor might have a cutoff amps for high and low. We don't know what the programming is.

For 150' you want at least 10 awg.

The IntelliFlo should be ok as long as the rpm and amps are low enough to keep the voltage loss down to 5% or less. IntelliFlo shows power, so you can calculate amps.

The main problem is that the installation won't meet Pentair's instructions and might not meet local code.

I would start with checking all electrical connections to make sure that they are good.
 
240 volts at 20 amps at 150' run with 12 awg wires gives a voltage drop of 9.53 volts, which is about 4% of 240 volts.

That's an acceptable wire size. IntelliFlo specifies 10 awg. Local code might find it acceptable.

I think that since you're getting 2 to 4 times the expected voltage drop, it's going to be due to bad wire connections.
 
I should clarify my voltage drop calculation:
120V on a 150 foot run and 12AWG = Voltage drop: 9.53
(so wouldn't the voltage drop be double? 9.53 per line or 19.06? or 7.9% drop)

Not sure this applies since each line has its own terminal on the quadplex breaker but 240V (2 conductors per phase in parallel) on a 150 foot run and 12AWG:
Voltage drop: 4.76
Voltage drop percentage: 1.98%
Voltage at the end: 235.24

Remember my Voltage was 243V measured at the motor when powered but not running, 233V when running dry, and 220Volts when the basket was primed just before it cuts out.

If it was bad connections in the wiring, would I have measured 243V to start?

I think it will be informative to check the voltage drop on the other motor. I should probably go out and get a clamp amp meter and check that while I'm at it.

VD = Voltage drop (http://ecmweb.com/code-basics/dont-let-voltage-drop-get-your-system-down)
I = The load in amperes at 100%, not 125%, for motors or continuous loads

R = Conductor resistance (2 Ohms/1000 ft) = 0.002/ft (150ft doubled for 2 lines, so 300ft x 0.002 = 0.6V)

VD = I x R

With the line powered but motor off. The controller draws minimal current say between 2-5Watts or 0.02A. VD = .02A X .6V = 0.012V
I measured 243V
So if the motor were working perfectly I would expect VD = 16A x 0.6V or a 9.6V drop that is driving the load.
I measured 233V with the motor running dry (This value is not too far off from what the calculations would suggest)

BUT ... I measured 220V with the motor primed. The conductor resistance would not have changed so the formula would be 23V voltage drop = ???? x 0.6V where ???? is equal to 38A.
If my measurements and calculations are correct, the increased amp draw could only have come from the motor.

I'm obviously no expert here but that seems to follow doesn't it? Increased conductor resistance due to bad connections could still be an issue I guess. But if the motor is not the cause then the amp draw of the motor would have been constant in the dry vs primed conditions and there would have been no voltage drop.

I guess I did these calculations on the MaxAmps of the motor rather than the nominal current but the logic would still hold.
If nominal current is 10A then:
(powered). VD = .02A X .6V = 0.012V I measured 243V
(Running dry) VD = 10A x 0.6V or a 6V drop that is driving the load. I measured 233V with the motor running dry
(Primed) Calculation unchanged 23V voltage drop = ???? x 0.6V where ???? is equal to 38A. and the maxAmps should have been 16A

I don't see a specification for wire size in the 0110118 Intelliflo installation guide other than the need to use a "bonding conductor not smaller than 8 AWG." It does say to follow NEC and local codes.
That would still put me at 12AWG & 20A for the motor alone. As you stated 10A might be better given the length of the run.
 
The voltage drop is 9.53 total, not per line. That puts the loss at just under 4%.

The voltage drop depends on the resistance (impedance) of the conductors (wires, switches, connections etc.) and the current.

The voltage drop is directly proportional to the current. With low load, you get low voltage drop.

Running dry pulls about 44% of the amps of fully primed. Running dry will have about 44% the voltage drop of fully primed.

The resistance (impedance) of the conductors stays the same.

Wiring the IntelliPro VS-3050
To connect the IntelliFlo VS to an AC power source:
1. Make sure all electrical breakers and switches are turned off before wiring motor.
2. Make sure that the wiring voltage is 230 VAC ± 10%.
3. Use #12 AWG for wire runs up to 100 feet and #10 AWG for lengths longer than 100 feet. When in
doubt use a heavier gauge (larger diameter) wire. Heavier gauge will allow the motor to run cooler and
more efficient.
Click to expand...
This is in some manuals. They might have removed it. You can Google part of this to find it. You're ok as long as the wiring complies with your local code.

I think that the main thing you're missing is that your calculations assume that the impedance is equal to 150' of #12 wire.

However, that's only if the wire is all good. I think that the wiring impedance is probably equivalent to 300 to 600 feet of #12 wire due to bad connections.

We're also missing the amp draw. We're assuming somewhere between 10 and 20 amps. If we could get the exact current, that would help. I'm guessing that it might be about 11 to 12 amps if the controller shuts off if it detects amps at 110% to 120% of full load amps.
 

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If you put 600 feet into a voltage drop calculator and use 0.05 amps for powered but not on, 5.3 amps for running dry and 12 amps for full prime, you will see a close match to your results.

It's the same concept in plumbing. A 1.5" 90 degree fitting has as much resistance as 7.5 feet of straight pipe.

A bad wiring connection can have as much resistance as several hundred feet of wire.

In other words, while it's only 150' of wire, it is acting like 600 feet of wire due to bad connections.

We can assume that the motor is not pulling over 20 amps because the breaker is not tripping (unless the breaker is bad).

If we use 20 amps and 150' of #12 wire, the expected voltage drop is 9.53 volts. However, you're getting 23. That's 2.4 times what's expected.

Your wire resistance is at least equal to 350 feet of #12 wire.

That indicates that the wiring is equivalent to 350 to 600 feet of good wire.
 
If I understand correctly. Your saying the resistance from bad connections is going to vary with the load also? Ok. So definitely checking the other motor on the current line and with the line to the suspected bad motor would yield some useful information. Unless it is at the breaker since they share the same quadplex breaker. But if that is the case then somewhere along the line there would be a lot of heat being generated right?

This is turning into quite an education. Thank you for all your help JamesW! Hopefully, I can do the investigation this weekend and report back.

I would like to get this resolved in the next week or two. I'm giving a whole new meaning to the phrase "going green" ;-)
 
There are three factors. Resistance, amps and voltage drop. If you know any two, you can calculate the third.

We only know voltage drop exactly. We are assuming that the amps are somewhere between 10 and 20.

We assume that the amps are above 10 because the motor's overcurrent protection is tripping. We assume that it's less than 20 because the circuit breaker is not tripping.

The resistance stays the same. The amp load is changing and the voltage drop is changing.

The voltage drop is directly proportional to the amp load. If you double the amp load, you double the voltage drop.

If you check the voltage at the end of the wires with no load, you will have no voltage drop. You will measure the same voltage at the end of the wires as at the breaker. Only when a load is applied will the voltage begin to drop.

If we knew the exact amp load and voltage drop, we could calculate the resistance.

Since we only know (assume) the approximate amp range, we can only calculate an assumed range for resistance. The assumed range is equivalent to about 350 to 600 feet of #12 wire.

Since the actual distance is only 150 feet, we can assume that there is a problem somewhere. Most likely, it's bad connections.

Any time current flows through wires that have resistance, there will be heat generated. The heat is dissipated over the length of the wire, so the wires won't get excessively hot unless they're overloaded. They might only heat up by a few degrees.

A bad connection can have the same effect as adding hundreds of feet of wire. The connection will generate the same amount of heat, but it will be concentrated in a small area. This can cause the connection to get very hot.

As the connection continues to deteriorate, the resistance increases and the area gets hotter and hotter until it eventually fails by melting or burning.
 
Finally got a chance to pick up an ammeter and measure the amps on the motor. On both lines (measured separately) the amps jumped up to 60 when the motor kicks on.
That is way above the maxAmps on the nameplate.

I can still check the voltage and amps if I rewire it to the booster motor to see if the volts and current are ok. That should isolate the problems to the motor itself.

My new intelliflo came this weekend. Looking to start re-piping this weekend assuming the electrical is ok.
 
Could be a bad motor. I suspect that the wiring has issues that contributed to the motor failing. I would recommend that you have the wiring checked by an electrician before installing the Intelliflo to make sure that the motor is going to get good power.

VS pumps are susceptible to failure due to power quality problems.
 
You can try putting a load on the line to see if the voltage drops out. You can use any 240 volt load. If you don’t have something handy, you could get a 240 volt heater element for about $7.00 at a hardware store etc.

You would want something between about 2,000 watts and 4,500 watts. Measure volts and amps at the same time to see what happens.

You could use a water heater element, but that would be damaged by dry firing.

You could use a stove top electric element. Just make sure that it’s 230 volt and about 2,000 to 4,000 watts. Example.

New Range Burner part number MP21YA.This is a large 8" burner 2100 watt 230v 5 turns.

It will get hot, so make it safe.

This will give you a steady load. Ideally, you don’t want more than a 5% voltage drop at 20 amps. At a starting voltage of 240 volts, you wouldn’t want to see the voltage drop to less than 228 volts. At 10 amps, the voltage drop should not exceed 6 volts, so not less than 234 volts.

The pump might be pulling more than 20 amps, but that would point to a problem with the breaker since it's not tripping.

Don’t do anything that you’re not sure that you can do safely.
 
So I put my booster pump on the lines for the old pump and it ran fine. It ran a steady 240V without a drop and the amps were also steady at 5.8 per line. (These were the same readings the booster pump gave on it's own power lines).

I think the current draw of the old motor was too short to trip the breaker.

I have two questions about installing the new pump:
1) currently I have no way to drain the pool without backwashing the DE filter. Would you recommend adding another 3 way or other valve to allow for draining. I've been doing the old fashion garden hose drain with all this rain and no pool pump.

2) I want to put union connections on the pump but I am not sure how to order the correct ones. Somewhere I read (maybe incorrectly) that Pentair had unique threads but I don't see any part numbers on their website. Are there recommended brands or types of unions for the Intelliflo 011018? Is this "hi-temp union" what I need? https://www.amazon.com/PACK-Hi-Temp-Union-Whisperflo-Intelliflo/dp/B00AKMV4K8

Here are some others I found by searching: Pentair, Unions, & 011018:
http://www.poolcleaningparts.com/pentair-intelliflo-pump-unions.html#tab-2
https://www.poolzoom.com/pump-2-inch-union-cpvc-21063-200-000-cmp.html
http://qpzr7.com/intelliflo-2-threa...ntair-intelliflo-pool-pump-2-pack-163761.html

I need threaded on one side and slip on the other for 2" pipes.
 

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