Century B973 as new motor for hayward superpump?

Jump to latest Follow Reply
Diver

Diver

Well-known member
May 5, 2011
493
South of Boston
A.O. Smith STS1072R 2 speed motor is usually mentioned on this forum as a replacement for hayward super pump, but it's 230v only. I was wondering if this motor

Century B973 3/4-1/8 HP 115 V 13.6/3.9 Amps 6 3/8 dia. Frame Century 2 Speed Pool Pump Motor - B973

http://www.emotorpro.com/3418hp115v13639amps638diaframecentury2speedpoolpumpmotor-b973.aspx

B129.jpg


would fit superpump 56J frame? it mentions that it's 6 3/8 diameter frame on the site above, but on http://www.poolcenter.com/motor_parts.htm it mentions it having 56J frame, so i'm wondering if 6 3/8 diameter frame and 56J frame is the same thing?

does anyone know if it has a high/slow speed switch or if one can be easily fitted?
 
56j frames come in two diameters. I believe the SuperPump uses the smaller diameter version. Bolt pattern is the same but if the diameter is different, you might need to change the support.
 
It is the diameter of the motor housing that is different. The part that sits on top of the plastic mounting structure (17 & 18). It is less than 6 3/8" but I don't have the exact size. This will place the shaft and mounting bolts too high to mount with the wet end (7). You might be able modify the support structure but I am not sure about that. You could raise the wet end relative to the motor but then that will change the suction pipe height.

Notice in the picture that the mounting bolts are outside the motor housing but in the B973 picture they are on the inside of the housing. The bolts are at the same diameter but the housings are different sizes.
 
mas985 said:
Notice in the picture that the mounting bolts are outside the motor housing but in the B973 picture they are on the inside of the housing. The bolts are at the same diameter but the housings are different sizes.
Click to expand...

that kinda looks that this motor can't be mated with the superpump's wet end - i would have to reverse the direction the mounting bolts are going but there would be no way to drive the bolts from the mounting plate back to the motor. am i seeing it right?
 
The mounting bolts are exactly the same and are threaded in the motor flange so that is fine. The only difference is that the motor housing has a different diameter. If the SuperPump motor support (17 & 18) can be lowered in some way to accomodate the larger diameter, then it should work ok.

Another option is to search for a direct replacement using the Hayward part# SPX1607Z2MS. That should be a direct replacement but I have noticed that some places show the larger diameter motor for that number.
 
Mark,

The direct replacement (A.O.Smith STS1072R) is 230v and is more powerful (1HP + 1.5SF). B973 is 115v and SFHP (1.125) matches better with what I need and that’s why I was looking at it in first place. Placement wise I think I could make it work by coming up with support structure to align motor with the rest of the pump.

But I got myself completely confused with the wiring for 2 speed motors! Not many diagrams are available online and that doesn’t help.

Single phase single speed motor that I have has 3 wires – ground, neutral and hot. Dual motor with a switch on the motor would have the same wiring (I assume) and the switch would change the speed of the motor using motor circuits.

I inquired the site that sells B937 motor about the high/low speed switch and they told me that there was no switch on a motor. I searched for different wiring diagram and it looks like some motor have separate wiring for high and low speeds. Is it safe to assume that dual speed motor without a switch would have such wiring? And how would it work? The diagrams call for high and low speed wires. Where would I come up with a high/low speed wire?

Right now I don’t even know if my pump is running on 115v or 230v. I’m going to take a look at the timer model to see if it’s for 115v or 230v. It does have 4 wires on the bottom, and it’s possible to combing 2 hot wires with a phase shift to get more then 115V, but with 120 degree shift it would be about 190v and not 230v. So I doubt I have 230v. If I can’t figure it out by looking at the timer, I will take apart switch at the equipment pad and measure the voltage directly there.

Someone (JasonLion?) on this forum mentioned that it’s possible to switch 115V breaker to 230V breaker at the switch panel to get 230V – which I also don’t understand how. The breaker simply cuts the line when the current exceeds the threshold, but it doesn’t step down/up the voltage. Unless there is one that does that. Is there?

As you can see I’m all confused :)
 
Most 2 speed motors will be either 240v or 120v but it is very rare to find one that will support both because of the rewiring required to go from 240v to 120v for each of the set of windings.

Anyway, if the motor is a 120v, then there will be four connections, one ground, one neutral and two hot, one for low and the other for high speed.

For 240v, you will also have four connections, one ground, one common and two hot. But the common is the one leg of the 240v and the other leg goes to either low or high speed.

Also, the US uses split phase power to most single family residential units. This is not the same as feeding only two phases of three phase power. You can read about that here. Anyway, there are three lines coming into the house, one neutral and two lines that are 180 degrees out of phase form each other. This is why 240v is twice 120v. If you have two phases of the three phase power, the voltage between the lines becomes sqrt(3)*Vo or 208v where Vo is 120v line to neutral. Some multi-family units use this type of power.

In the breaker box, the two hot lines alternate between breakers so two vertical breakers will have 240v between them. So when feeding a 230v pump, you use two breakers without the neutral.
 

Enjoying this content?

Support TFP with a donation.

Give Support
mas985 said:
If the SuperPump motor support (17 & 18) can be lowered in some way to accomodate the larger diameter, then it should work ok.
Click to expand...
There is an adaptor (SPX2600Q (Mounting Foot Adapter))that will allow either diameter to work. It is shown in the picture, but not identified.

For the larger diameter motor, the adapter is not used.

[edit]I'm not sure that all Superpumps have the spacer/adaptor. I saw a Superpump (SP2607X10) today and it looked like the mounting foot was one solid piece as shown in this parts diagram.

If you are changing from a smaller diameter motor to a larger diameter motor, and you have the spacer/adaptor then you just remove the spacer/adaptor to accommodate the larger diameter motor. If the mounting foot is the solid piece, I think that you should be able to cut down the back motor support to accommodate the larger diameter motor. [end edit]
 
Mark,

I'm going to educate myself a little bit on the wiring and also I will take the back of my superpump motor off this weekend to see if the jumper is on 115v or 230v position - this way i will know for sure the voltage. I also want to see how many wires are going to my single speed motor and how i can rewire it for 2 speed. I will report back if I'm still somewhat unclear.

James,

Thanks for the heads-up on the mounting adapter, I will keep it in mind.
 
ok, i got some things figured out :)

i took the end cap from my superpumps motor this morning. i have a jumper switch on the motor set at 240V, so now i know the voltage. i also have 3 wires (not counting ground wire) coming to the motor, all three of them a green :). One of them is neutral and the other two are 120V. so now i know the wiring.

So it seems that i should be all set wiring this to a two speed 240V motor with a switch or i can buy an end cap switch and a motor without it. STS1072R seems as a good motor to replace my existing one.

So for 2 speed 240v motor - does the slow speed run on 120V and high one on 240V? that's how it works?
 
Both high and low speeds run on the same voltage but different connections. You will have four terminals for 240v. Ground, common, high and low. 240v goes between common and high OR common and low which is why you need a switch to change speeds. A two speed timer will also work.
 
gotcha. looks like the end cap switch assembly (#615332) that is being sold around for STS1072R doesn't fit aosmith motors anymore:

We stopped carrying this product because it did not fit the AO Smith motors. You may be able to contact AO Smith to see if they have any further updates for a switch that is compatible with their motors. 770-734-9696/ 937-667-2431 www.aosmithmotors.com

Inyo Pool Products
www.inyopools.com
Click to expand...
 
You must log in or register to reply here.
Thread Status
Hello , This thread has been inactive for over 60 days. New postings here are unlikely to be seen or responded to by other members. For better visibility, consider Starting A New Thread.
Top Bottom
Back
Jump to latest Follow Reply