Identifying Spa Pump & Motor Replacements



www.RickRobinsonHomes.com

Identifying Spa Pump & Motor Replacements

Identifying a correct motor or pump replacement for a spa can be a tricky business: motors come in various sizes, pumps can have non-standard (up-rated/brake horsepower) ratings, sometimes the horsepower rating will be blank. Correct identification can make the difference between a profitable parts sale/service call and an expensive mess.

Let’s cover some of these terms:

• Up-rating – The practice of labeling a motor at higher than its traditional horsepower rating. For example changing a 2 HP pump into a 3 HP pump by only changing some of the ratings on the sticker.(See Brake/SPL ‘Special” Horsepower)
  
• Frame Size – Motors come in different sizes, we define these standard sizes by motor frame numbers. Unfortunately these motor manufactures do not agree on the terms they use for these frame sizes. For simplicity we refer to standard spa motors as 48Y and 56Y, but motor manufacturers call them all sorts of things. Some motor manufacturers even call the 48 frame motors 56 and vice versa.
  
• Brake/SPL “Special” Horsepower – These are commonly used for even bigger “up-ratings” a 2 HP pump can change to 4.5 HP or higher merely by changing the sticker on the motor. This rating is primarily based on the HP the motor attains less any load. True HP is the rating of the motor under load, this is the most important rating we as techs look for.
• 
  With horsepower ratings you cannot trust and frame sizes called all sorts of different things – what are you to do? The best weapon in our quest to identify a correct replacement is careful observation. We can identify frame size with a ruler and noting where the bolts are, we can get an idea for the horsepower by observing the amperage & voltage and find out one speed or two speed with the RPM rating. Everything we need to know is at hand you just need to know what to look for.
  
• Below is a checklist of things we use when identifying a pump. We don't always them all, but the more you know the more likely it is you will get it right.
  

• Pump ID checklist:

  • Amperage
  • Voltage
  • RPM rating
  • Pump brand
  • Pump model
  • Motor diameter
  • Impeller part number
  • Pump casing part numbers
  • Number of screws that hold the pump wet end together
  • Shape of the pump faceplate
  • Distance between motor thru-bolts and the head size.
  • Position of motor thru-bolts
  • Pump discharge location
  • Pump suction location
  • Outside thread diameter of suction and discharge

What do we do with all that?

Amperage and voltage – Normally the correct replacement will be the same voltage and near the same amperage.
RPM Rating – A 3450/1725 rating means you have a 2 speed motor, a single 3450 rating means you have a standard 1 speed motor, a single 1725 rating means you have circ pump motor, ratings of 2850 or 1425 mean you have a 50 hertz overseas motor.
Motor diameter – 48 frame motors are around 5-1/2” in diameter, 56 frame motors are around 6-3/8” diameter.
Distance between motor thru-bolts – 48 frame motors have thru-bolts about 3-5/8” apart, 56 frame motors have thru-bolts about 4-1/8” apart.
Thru-bolt head sizes – 48 frame motors usually have 1/4” heads on the thru-bolts, 56 frame motors usually have 5/16” heads.
Mounting Bolt Pattern – The distance between the bolts on the 48 frame bolt pattern = 3.65". The ditance between the bolts on the 56 frame = 4.1".
Pump brand/model – Replacing a pump with exactly the same pump will ensure a good fit. With most pump models only one motor size fits, eliminating a lot of the frame questions.
Pump case/impeller part numbers - These will usually lead to a particular pump model, and the impeller numbers to a model and horsepower. If there are no part numbers we can use basic shape and number of screws to try and narrow down to a pump model.
Outside thread diameters (where the plumbing hooks up) - The common thread sizes are 1.5” Buttress = 2-7/16” diameter, 2” Buttress = 3-1/16”diameter and 2.5” Buttress = 3-11/16” diameter.
Thru-bolt locations – most motor bolts that attach pump and motor are located at 11:00, 1:00, 5:00 and 7:00 O’clock. If yours are located elsewhere, ask before ordering a motor.
Pump discharge location – some pump discharges are located directly in-line with the motor shaft (they may be straight up or point left or right) we call these “center discharge” pumps, some pump discharges are set off to the right side of the wet end we call these “side discharge” pumps.
Pump suction location – most pumps have the suction is in the center of the wet end, 100% Drain pumps have them lowered to the bottom.
As you can see there are a number of things to consider when selecting spa pumps and their parts, if you follow the guidelines above you will find it is not hard to get it right.

This Article Supplied by Spa Parts Plus.

Until Next Time...

How to replace the seals in your pump

Rick the Spa Guy

The following is my easy (LOL) to follow steps for, How to replace the seals in your pump.


The following tips are general there are MANY pumps out there and a lot of pumps use different seals, this being said I will discuss the most popular types of pump seals out there.


The first thing to do is identify what pump you have and then which seal assembly is used in that type of pump. If you look on the label of your pump there usually will be a name for the pump like Aqua-flo, Theramax, Duramax, Flow master etc. Once this info is obtained you can google that pump name to find out which seal assembly is needed. Example's of seals are PS200, PS201, PS1000.

PS 200 seal assembly

Now once you have the seals you will need to remove the pump from the spa to more easily make the repairs.


Once the spa pump is removed you need to open the back cover of the pump where the wires go and locate the pump shaft (some motors will just have a small round cap on the back, in the center of the motor remove this cap to expose the back of the shaft). You will need a good strong flat head screwdriver and vise grip pliers to hold the shaft still.

Power Flo pump

Once you located the shaft and know where you can grab it to hold the shaft still you need to remove the pump face plate, there are several small screws on the front of the pump, remove these and pry off the pump face plate and set to the side. Once open you will see the impeller inside the housing this is what turns to push the water through the pump, the seal assembly is located behind this impeller. 


Hold the shaft still and reach into the front of the pump and turn the impeller counter clockwise to unscrew the impeller off the pump shaft, this will expose the seal assembly. Seals have 2 parts to them as pictured above, the white ceramic seal and the spring type mechanical seal, when these two pieces get compressed they form a water tight seal between the plastic pump end and the metal motor end of the pump assembly.

Impeller front and
Picture courtesy of
Spa Parts Plus

You will see how these two seals are installed once you separate the impeller from the shaft, remove the old seals and REMEMBER which part of the seal goes where. The white ceramic part must come in contact with the raised part of the mechanical seal as pictured above. 


So once you removed the old seals and you are installing the new spring type mechanical seal be careful not to damage it, you may need a SMALL amount of lubricant to get the seal so slide into place be sure it is snug fitting, sometimes the mechanical spring seal is installed on the back side of the impeller and and the ceramic is pressed into the rear housing of the pump sometimes this is reversed, it is very important that you know what part goes where, take a picture once you have the pump apart you you can reference it later if needed.


Now you have the seals installed and it is time to re install the impeller and re install the front face plate of the pump. There is also an o-ring on the back of the face plate you may want to replace this as well. Once all this is done just re install the pump fill the spa and check for leaks. It sounds harder than it is. LOL just take your time and you will be fine.


Until Next Time...