Motor replacement advice

[SilverSD]

I have a century 2 speed motor which appears to have died. (1.5 HP, 1.47sf, 2.2tot HP 115v). By the serial number it is only 2-3 years old.

I'm getting a fault 7 error - turn motor shaft.

I tore it apart. No plumbing obstructions. Impeller and shaft both turn freely. Start capacitor tested good. Replaced it anyway. Tested motor again still separate from pump housing and got the same error. Maybe the windings are bad ?

Assuming I need to replace it I was wondering if I'm better off replacing the pump housing as well.

It is much older and has likely served several motors but still appears to be in good shape (we just moved in so I'm not sure of the history). It is labeled:
Purex-Triton Whisperflo 1 HP 1.65SF

My first question is whether the pump is sized correctly for the current motor ( 1.5 HP motor but pump housing is labeled 1hp). So why is the pump a lower HP than the motor? Does that mean the impeller is incorrectly sized?

Second question: if we wanted to put in a variable speed motor can we do that with the current pump housing or would we have to change the pump out? If we have to change the housing also is it worth going from a 2 speed to a variable?

Third question: where are recommended places to shop?

My stats- 33,000 gal pool. 8 hr cycle or 70 GPM flow. DE filter is sized up to 70. I calculate my head at tdh=33 with 2 inch PVC.

Thanx

 

[mas985]

I'm getting a fault 7 error - turn motor shaft.

Where are you getting that error? Most two speed motors have no readout.

My first question is whether the pump is sized correctly for the current motor ( 1.5 HP motor but pump housing is labeled 1hp). So why is the pump a lower HP than the motor? Does that mean the impeller is incorrectly sized?

It is ok to put to a 1.5 HP motor on a 1 HP pump. But the other way around is an issue. If you want to confirm the pump "Size" look for the impeller part number.

Second question: if we wanted to put in a variable speed motor can we do that with the current pump housing or would we have to change the pump out? If we have to change the housing also is it worth going from a 2 speed to a variable?

You could put a variable speed motor on the current wet end if you wanted to go that route. Depending on the frame type:

A.O. Smith 1.65 HP Variable Speed Pool Pump Motor Round Flange - ECM16CU - INYOPools.com
A.O. Smith 1.65 HP Variable Speed Pool Pump Motor Square Flange - ECM16SQU - INYOPools.com

 

[JamesW]

Fault 07 is overcurrent. The only 115 volt two speed is the B2981T, which has a total of 1.25 hp. If your whisperflo is 1.65 hp total, then that would overload the motor.

The 1.5 hp motor is the B2983T, which is 230 volt only.

Can you confirm the motor model number and supply voltage?

 

[SilverSD]

My mistake. I thought the motor would have four wires for 230v. Mine only has line, load, and ground. But it does occupy two slots in the panel and the model is B2983T.

 

[JamesW]

If you have something that says Line and Load, that's usually a switch, like a timer.

The wires going to the switch would be "Line" wires. The wires going from the switch to the motor would be "Load".

For 230 volt, there would be two colored wires (usually black or red) going to the motor.

Note: Wires coming from a power supply are "Line" wires and wires going to an appliance are "Load" wires. Wires going from a switch to an appliance are "Load" wires from the perspective of the switch but they are "Line" wires from the perspective of the appliance.

 

[tim5055]

For 230 volt, there would be two colored wires (usually black or red) going to the motor.

Careful with this description.

I would say "For 230 volt, there should be two colored wires (usually black or red) going to the motor." The only way to be sure is with a meter. I have found numerous "handyman installations" where they used standard romex for a 220v application and did not tag/flag the white wire as a "color".

 

[JamesW]

Good point.

 

[SilverSD]

All right. I used the terms for a switch because mine are the typical white, black, and copper. I guess I could grab the meter to confirm but it is the B2983T.

Any thoughts on the fault 7 error? Or recommendations on where to get a variable speed that would fit?

 

[JamesW]

Check voltage at the pump terminals. Black and white suggests 120 volts. However, as noted above, that might just be from someone not using the correct color wire.

If it is 120 volts, that could be the problem. But, I really would think that the pump wouldn't work at 120 volts at all. [Edit]It might work because the motor is oversized for the impeller.[End Edit]

You could go to a small pump (total hp less than 1.0) or 2 speed or variable speed.

California won't allow a single speed pump at 1.0 total hp or higher.

Based on your electrical rates, I would consider a variable speed pump. Maybe a FloPro VS, SuperFlo VS, or one of the Hayward pumps.

I wouldn't rebuild the current pump. Since it says Purex, it's really old.

One issue with a variable speed pump is that it needs power all of the time, which can cause problems when it turns off because the salt system is still powered.

 

[mas985]

One issue with a variable speed pump is that it needs power all of the time, which can cause problems when it turns off because the salt system is still powered.

Why does it need power all the time? Most VS pumps if not all that I know of have built in memory so they can be powered off for more than 48 hours before losing any of the timer settings. These include all of the major lines, Intelliflo, SuperFlo, MaxFlo, Ecostar, etc.

 

[JamesW]

I thought that it was preferred to keep the pump powered all the time. If it is OK to power off on a regular basis and the pump will not lose settings or otherwise be adversely affected, that can help with avoiding conflict with salt systems.

 

[SilverSD]

From the timer manual:
OVERCURRENT Fault 07 - Remove power and rotate shaft. Wait for maximum 1hr. and take necessary action. It is due to the locking of shaft.

Like I said before. I'm not sure of the history of the pump but we have been in the house since August and it was working fine (although the prime wasn't great - it always had some air). I doubt there had been any recent work on the pump/motor given the difficulty I had in taking it apart. Based on the motor serial number (12214J2) it looks like the motor is 2-3 years old. Could this problem be due to a mis-sized impeller if they increased the HP of the motor when it was replaced 2-3 years ago? Would it take that long to kill the motor?

Actually the motor still seems to be trying to run. It starts for 1-2 seconds and then shuts off with the Fault 7 error showing on the timer screen.

It can't overheat in that amount of time.
The impeller and shaft turn freely and smoothly. No resistance at all.
It is not due to a blockage and I t the same error when the motor is turned on when disconnected from the pump housing.

Just wondering if I'm missing anything else before I plunk down for the new pump and motor. The motor really seems to be in good shape and I am loathe to buy a new one if I don't know how/why the old one died. Any other suggestions on how I could test it?

Double checked voltage at the motor. And I have 120V on L1 and 120V on L2. (240V total across L1 L2).

 

[JamesW]

Are you getting 240 volts measured line to line while the pump is on?

Note that it's important to measure line to line, not each line to ground and added up.

It's also important to check voltage under load, because the voltage might check ok with no load and drop off considerably once a load is applied.

If yes, I would recommend checking amps, if you're comfortable doing that.

Maybe check the capacitor. If you take it to a motor repair shop, they can check it. Or, just get a new one and try that.

If the capacitor is bad, it will make the power factor be off, which causes the amp draw to increase.

An undersized impeller won't cause an over current problem.

 

[SilverSD]

Thanks @JamesW. They were measured individually to ground but line to line for the total. I'll measure again when the motor is turned on. Unfortunately, I don't have a clamp meter to measure amps.

The capacitor checked out. I replaced it anyway but it didn't make a difference.

 

[SilverSD]

OK. That was interesting. The motor hasn't worked in weeks but when I went to test the voltage it ran! Even when I had it pulled off the pump it would run about only 2 second and shut off. But when I primed the basket and put on the lid it stopped.

Powered not running - 243V
Motor running - 233V
Primed and running- Voltage drops to 220 and shuts off.

So what do you motor experts make of that? I could use your analysis.

 

[JamesW]

That's a big voltage drop. Can you measure amp draw?

Maybe a problem with the motor or maybe the supply breaker or wiring.

Might be worthwhile taking the motor to a local motor shop for evaluation. Usually it's a reasonable fee for diagnosis.

If the motor checks out ok, you might want to have the supply side checked for problems.

 

[SilverSD]

Unfortunately I don't have an induction clamp meter to measure amp draw.

I'll try to test it at the breaker. Maybe I'll get lucky and have a bad breaker. That sounds easier to check than pulling the motor out again.

We are getting storms coming in for the next couple of days so I'm not sure how much I can do on it.

 

[SilverSD]

Kinda funky breaker the way they are connected together. What is the best way to test this type of breaker? All four lines individually?

 

[JamesW]

I would recommend that you get the motor checked at a motor shop. If that checks good, have an electrician check the supply.

 

[SilverSD]

I checked the voltage at the breaker when the motor turns on and there was a small dip but nothing significant (239V to 233V). I spoke to a local motor repair shop and gave them the details and info off the motor nameplate. Their advice was that it wasn't even worth bringing it in for diagnostics, since the inspection fee and repair costs would exceed the cost of a new motor.

JamesW - you pointed out that my pump is quite old and suggested getting a variable speed.

I agree and think that would work best for different scenarios - basic circulation/SWG, Suction cleaner, or spa only etc.

I have been reading about some of the different brands -

Hayward Ecostar, SP3400VSP, 3HP variable speed pump - Generally considered more efficient and lower cost
Pentair Intelliflo, 011018, 3HP variable speed pump - Universally acclaimed, generally considered to have better longevity

JamesW - Would you recommended the Superflo over the intelliflo for my pool? I guess I am more worried about longevity and would rather have the higher HP and run at a lower RPM

Other possible considerations - I'm guessing the my TDH is quite high due to 2 skimmers multiple pool returns, 2 drains, 8 spa returns. On top of that, the pump etc is 30 feet away (50 feet from the deep end of the pool. )
Historically, with the old and possibly dying motor, I would consistently get high pressure readings between 20-30. Even after a full cleaning of the DE filter it would still be in the 15-20 range but didn't seem to stay there for long (crystal clear pool with high FC so it wasn't algae).

All that to say, I am leery of under sizing the pump and limiting my flexibility. So am I falling into the classic pattern of buying too much motor?