skos Posted April 18, 2011 Report Share Posted April 18, 2011 A year ago my pump went out and I replaced it with an A.O. Smith B130 2.4hp. I believe my old pump was a 2hp. I have a 14K pool with 2 skimmers, a fountain in the spa that flow like a waterfall back into the pool and a sheer decent feature. Also went the pump went out it collapsed a lot of the DE grids. I replaced all the grids. Now I noticed after a couple of month that a couple of grids are collapsed again and I constantly have low pressure issues. After I replaced the pump and grids I had 20psi. When I have low pressure in the pool issues it is up to 30psi. I can back wash and I am back to 20psi. Any ideas on the grids issue? Thanks STeve Quote Link to comment Share on other sites More sharing options...
waterbear Posted April 18, 2011 Report Share Posted April 18, 2011 What pump do you have? The motor you used is a full rated 2HP motor with a C frame and a service factor of 1.2 which is where the 2.4 brake HP comes in) . If your previous pump used an uprated motor then you used a motor that is too big (a 2 HP uprated is the same as a 1.5 HP full rated and a 2.5 hp uprated is the same as a 2 HP full rated motor) Providing the full pump model number will help us determine if the new motor is the problem. Quote Link to comment Share on other sites More sharing options...
skos Posted April 18, 2011 Author Report Share Posted April 18, 2011 What pump do you have? The motor you used is a full rated 2HP motor with a C frame and a service factor of 1.2 which is where the 2.4 brake HP comes in) . If your previous pump used an uprated motor then you used a motor that is too big (a 2 HP uprated is the same as a 1.5 HP full rated and a 2.5 hp uprated is the same as a 2 HP full rated motor) Providing the full pump model number will help us determine if the new motor is the problem. Thanks for your help. The motor shows A.O. Smith B130 2.4hp PN#7-159986 type CX and FR# X56J. So I should increase the load on the motor, thus reducing the HP like a variable motor? Quote Link to comment Share on other sites More sharing options...
skos Posted April 18, 2011 Author Report Share Posted April 18, 2011 Also what if I put in some sort of bag filter? That way I can cut down on how often the DE filter needs cleaning and reduce the pressure? Quote Link to comment Share on other sites More sharing options...
skos Posted April 18, 2011 Author Report Share Posted April 18, 2011 Update, when I start to lose pressure from the fountain, my filter reads 33psi. Also the motor filter basket is not completely filled with water. There is an air gap. Maybe an inch. So I can see air in the motor basket but this does not happen for maybe 6hrs of the motor running. So if I turn off the pump, wait maybe 5min and turn back on, we are back to 20psi and the fountain has pressure. Quote Link to comment Share on other sites More sharing options...
PoolGuyNJ Posted April 18, 2011 Report Share Posted April 18, 2011 What size is your filter? How old are the grids? In addition to what waterbear suggested, here are a couple of additionals. Possibility #1 It sounds like you trying to push too mush water in. This stretches the grid fabric. When there is no space between the plastic separator ribs, the grids insides can't collect filtered water. Pressure rises quickly. Possibility #2 The water is out of balance, possibly fighting a nascent algae bloom. Any green when you backwash? Scott Quote Link to comment Share on other sites More sharing options...
skos Posted April 19, 2011 Author Report Share Posted April 19, 2011 What size is your filter? How old are the grids? In addition to what waterbear suggested, here are a couple of additionals. Possibility #1 It sounds like you trying to push too mush water in. This stretches the grid fabric. When there is no space between the plastic separator ribs, the grids insides can't collect filtered water. Pressure rises quickly. Possibility #2 The water is out of balance, possibly fighting a nascent algae bloom. Any green when you backwash? Scott Thanks, no algae. Update, when I start to lose pressure from the fountain, my filter reads 33psi. Also the motor filter basket is not completely filled with water. There is an air gap. Maybe an inch. So I can see air in the motor basket but this does not happen for maybe 6hrs of the motor running. So if I turn off the pump, wait maybe 5min and turn back on, we are back to 20psi and the fountain has pressure. Aqualink rs4 Hayward DE2420L Filter AutoClear salt system Quote Link to comment Share on other sites More sharing options...
waterbear Posted April 19, 2011 Report Share Posted April 19, 2011 What pump do you have? The motor you used is a full rated 2HP motor with a C frame and a service factor of 1.2 which is where the 2.4 brake HP comes in) . If your previous pump used an uprated motor then you used a motor that is too big (a 2 HP uprated is the same as a 1.5 HP full rated and a 2.5 hp uprated is the same as a 2 HP full rated motor) Providing the full pump model number will help us determine if the new motor is the problem. Thanks for your help. The motor shows A.O. Smith B130 2.4hp PN#7-159986 type CX and FR# X56J. So I should increase the load on the motor, thus reducing the HP like a variable motor? I did not ask what motor you have, I already know since you stated that in your first post. I asked what pump you have to make sure you have the right replacement motor for your pump. Quote Link to comment Share on other sites More sharing options...
PoolGuyNJ Posted April 19, 2011 Report Share Posted April 19, 2011 It looks a 48 sq. ft filter and a Super II. At 33 PSI, the filter is dirty and needs a back wash. My next question is how long does it take to get there? When was the last time the grids were soaked in TSP to degrease them of skin oils and lotions? Scott Quote Link to comment Share on other sites More sharing options...
skos Posted April 19, 2011 Author Report Share Posted April 19, 2011 What pump do you have? The motor you used is a full rated 2HP motor with a C frame and a service factor of 1.2 which is where the 2.4 brake HP comes in) . If your previous pump used an uprated motor then you used a motor that is too big (a 2 HP uprated is the same as a 1.5 HP full rated and a 2.5 hp uprated is the same as a 2 HP full rated motor) Providing the full pump model number will help us determine if the new motor is the problem. Thanks for your help. The motor shows A.O. Smith B130 2.4hp PN#7-159986 type CX and FR# X56J. So I should increase the load on the motor, thus reducing the HP like a variable motor? I did not ask what motor you have, I already know since you stated that in your first post. I asked what pump you have to make sure you have the right replacement motor for your pump. waterbear sorry I do not understand your question. What is the difference between the motor and the pump. Isn’t the motor pumping the water? I also have a 3/4hp motor that drives the polars. Quote Link to comment Share on other sites More sharing options...
waterbear Posted April 19, 2011 Report Share Posted April 19, 2011 What pump do you have? The motor you used is a full rated 2HP motor with a C frame and a service factor of 1.2 which is where the 2.4 brake HP comes in) . If your previous pump used an uprated motor then you used a motor that is too big (a 2 HP uprated is the same as a 1.5 HP full rated and a 2.5 hp uprated is the same as a 2 HP full rated motor) Providing the full pump model number will help us determine if the new motor is the problem. Thanks for your help. The motor shows A.O. Smith B130 2.4hp PN#7-159986 type CX and FR# X56J. So I should increase the load on the motor, thus reducing the HP like a variable motor? I did not ask what motor you have, I already know since you stated that in your first post. I asked what pump you have to make sure you have the right replacement motor for your pump. waterbear sorry I do not understand your question. What is the difference between the motor and the pump. Isn't the motor pumping the water? NO, the impeller is pumping the water, the motor is just turning the impeller. It is actually an important distinction as I explain below. I also have a 3/4hp motor that drives the polars. NO, you have a 3/4 HP booster PUMP for the Polaris! It is more than just a motor! AO Smith only makes replacement (and OEM) motors, they do not make pumps. From the pics your pump looks like a Hayward Super II which comes in both full rated and up rated models in several different HP. The model number of the actual pump will tell us the HP of the impeller and volute and whether the pump was full rated or uprated. This way we know whether you have the correct motor on your pump or not. The motor needs to be matched in capacity to the wet end of the pump. The UP rated 2 HP is basically the same pump as the FULL rated 1.5 hp and will use the same impeller, volute, and motor. The UP rated 2.5 HP is basically the same pump as the FULL rated 2 HP and will use the same impeller, volute, and motor. Quote Link to comment Share on other sites More sharing options...
PoolGuyNJ Posted April 19, 2011 Report Share Posted April 19, 2011 The motor is just a motor. Like an engine to a car. Part of a whole. Motors typically rotate. It's what's attached to that motor that is of concern. The motor you have may be too much for your needs or it may suit what you want, specifically the fountain effect in the spa. How long does it take to go from your initial starting pressure to 33 PSI? At 33 PSI in the filter, the pump is meeting a substantial resistance. That is why the fountain drips in height. You are also using more power as resistance builds. The motor won't slow but the water flow going through the pump is. This will lead to what is known as cavitation, a vibration created when water can't get past the impeller on the end of the motor. Think of an impeller as if it was a propeller on a small plane. If you blocked air from the back of a plane's spinning prop, the prop has less new air to bite because the pressure behind it has increased and you're spinning the same air, not new air. The same thing is happening in the pump. If it takes a month of running your system to go from 20 to 30 PSI, that is normal. If it takes 2 days, that is not normal. Scott Quote Link to comment Share on other sites More sharing options...
Beelzy Posted April 21, 2011 Report Share Posted April 21, 2011 Too much Horsepower for that application.....also pop that Salt Cell out and check it, if it's clogged up it will raise the pressure also. Quote Link to comment Share on other sites More sharing options...
footie Posted April 21, 2011 Report Share Posted April 21, 2011 2.4HP sounds far too much for a filtration system in a domestic pool, mine is only 1/2HP (proper HP). Quote Link to comment Share on other sites More sharing options...
waterbear Posted April 21, 2011 Report Share Posted April 21, 2011 2.4HP sounds far too much for a filtration system in a domestic pool, mine is only 1/2HP (proper HP). actually, with a fountain and what looks to be a spillover spa from the picture (I assume there are jets there) 2 HP is about in the ballpark. Quote Link to comment Share on other sites More sharing options...
footie Posted April 21, 2011 Report Share Posted April 21, 2011 2.4HP sounds far too much for a filtration system in a domestic pool, mine is only 1/2HP (proper HP). actually, with a fountain and what looks to be a spillover spa from the picture (I assume there are jets there) 2 HP is about in the ballpark. That explains it. I thought there must have been some reason but couldn't figure it out. Blame doing my work whilst reading this post, in other words doing two things at once, something women keep telling us men we can't do. LOL Quote Link to comment Share on other sites More sharing options...
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