Sump Pump Question

John151 · « **on:** 24 Jul 2011, 10:00 pm »

I have two pumps in my sump:
1) Primary pump is a 3/4 Wayne submersed pump.
2) Back up pump is a 1/2 HP Zoeller Aquanot pedestal pump that runs on battery power.

The discharge of the two pumps are connected with a "Y" so there is only one discharge pipe leaving the house.

The other night we had a major monsoon dumping 6"-8" of rain in a few hours. Primary pump ran constantly, but could not keep up, so the back up pump kicked in (setting off the alarm). I kept a close eye on the pumps to make sure my basement did not flood. After several hours of operation on the back up pump I could smell something burning. I touched the top of the motor and nearly burned my hand - it was really hot. It did appear to be pumping fine, but I was concerned by the heat, so I disconnected it and let it cool off. By this time the rain had subsided and the primary pump was able to keep up (barely, pit was still near the top). Half hour later I connected the back up pump again and it ran fine and did not appear to heat up, at least not immediately.

The back up pump has run for extended periods before when the primary pump has failed and when the power went out - never noticed it getting hot before.

I pulled the back up pump out today and disassembled the pump (bottom of the pedestal) and could not find anything wrong - the pump was clean, pristine, and would turn easily by hand. I ran the pump on my work bench (dry), and it ran fine except for vibrating quite a bit (possibly from spinning faster than designed since there was no water to pump?).

My question is: Would the pump be running hot due to running along side another pump resulting in greater resistance? Or, is there likely something wrong with the pump? Is the vibration a concern, or would you expect the sump pump to vibrate pretty good when run dry on a work bench?

Thanks in advance.

thunderbrick · « **Reply #1 on:** 24 Jul 2011, 10:12 pm »

Did you have check valves in place for each pump? It may have been fighting the output of the larger pump. Do you have a larger output pipe coming out of the Y? If the pipes are all the same size the pumps may have difficulty pushing the combined water flow.

John151 · « **Reply #2 on:** 24 Jul 2011, 10:21 pm »

Quote from: thunderbrick on 24 Jul 2011, 10:12 pm

Did you have check valves in place for each pump? It may have been fighting the output of the larger pump. Do you have a larger output pipe coming out of the Y. If the pipes are all the same size the pumps may have difficulty pushing the combined water flow.

Both pumps have separate check valves (before the Y).

Diameter does not increase past the Y. I have been wondering if I should increase the diameter after the Y. Having separate discharge lines would take a lot of work as the discharge goes into the storm sewer.

I did check the flow rate of the discharge pipe outside the house that night and there was an amazing amount of watering exiting the house.

Big Red Machine · « **Reply #3 on:** 24 Jul 2011, 10:32 pm »

Is the back-up submersed? If not, then overheating will occur since they are not meant to run continuously.

JackD201 · « **Reply #4 on:** 24 Jul 2011, 10:49 pm »

Quote from: thunderbrick on 24 Jul 2011, 10:12 pm

Did you have check valves in place for each pump? It may have been fighting the output of the larger pump. Do you have a larger output pipe coming out of the Y? If the pipes are all the same size the pumps may have difficulty pushing the combined water flow.

+1

John151 · « **Reply #5 on:** 24 Jul 2011, 11:05 pm »

Quote from: Big Red Machine on 24 Jul 2011, 10:32 pm

Is the back-up submersed? If not, then overheating will occur since they are not meant to run continuously.

The back up pump is a pedestal type, so the motor is above water.

I believe this pump has run for prolonged periods before, but I can't say for sure that it did not get hot.

John151 · « **Reply #6 on:** 24 Jul 2011, 11:59 pm »

After giving this considerable thought, and reading all of the replies, I am going with "too much restriction in the pipe from the other pump" theory. Here's why - the back up pump was professionally installed along with a 1/3 HP primary pump. I later upgraded the 1/3 HP pump to 3/4 HP after the 1/3 HP motor failed to keep up in a major storm. I am guessing that upgrading from 1/3 to 3/4 HP primary pump changes the equation considerably.

Make sense?

Thanks for all of your replies!

Tone Depth · « **Reply #7 on:** 25 Jul 2011, 12:07 am »

It sounds like your backup pump is now mismatched by your upsized primary pump. You could add a separate parallel discharge pipe if feasible. Otherwise, you ought to have someone evaluate the system to determine needed improvements. At the very least, you need to reconfigure the float switches/control system to keep the pumps from operating in parallel.

John151 · « **Reply #8 on:** 25 Jul 2011, 12:43 am »

Quote from: Tone Depth on 25 Jul 2011, 12:07 am

It sounds like your backup pump is now mismatched by your upsized primary pump. You could add a separate parallel discharge pipe if feasible. Otherwise, you ought to have someone evaluate the system to determine needed improvements. At the very least, you need to reconfigure the float switches/control system to keep the pumps from operating in parallel.

Agreed. I plan to have a pro take a look and advise. As for the float switch, it does not engage until the pit is 3/4 full so it only engages when the main pump is not cutting it.

Ideally, I would get a 2nd pit, but not sure I am that motivated as that is a pretty decent sized project.

Mikeinsacramento · « **Reply #9 on:** 25 Jul 2011, 12:50 am »

Quote from: John151 on 24 Jul 2011, 11:59 pm

After giving this considerable thought, and reading all of the replies, I am going with "too much restriction in the pipe from the other pump" theory. Here's why - the back up pump was professionally installed along with a 1/3 HP primary pump. I later upgraded the 1/3 HP pump to 3/4 HP after the 1/3 HP motor failed to keep up in a major storm. I am guessing that upgrading from 1/3 to 3/4 HP primary pump changes the equation considerably.

Make sense?

Thanks for all of your replies!

No. If the RPM rating of the 3/4 HP pump was the same as the 1/3, there would be no changes to the system. I'm curious if you increased the RPM when you put the 3/4 on.

We oversize pump drivers all the time when we can't get exactly what we need in a timely fashion. As long as voltage/phase/rpm are the same, it doesn't really matter.

Don't ask me too many questions about this though, because you're talking about a dinky little residential thing. And I don't dwell in that realm. lol!

jackman · « **Reply #10 on:** 25 Jul 2011, 01:35 am »

I would email the manufacturer to see what they say. There is a lot of speculation from people on this thread but you really don't know if anything is wrong with the backup because it might be designed to operate a bit hot. My pump was going crazy last night but I don't have a backup. This thread reminded me of the need!

I installed a 1 hp pump when my old 1/2 pump got stuck in the ON position for a very long time. It was so hot, I could feel the heat from three or four feet away. I unplugged it but it, but when I plugged it back in the pump continued pumping, non-stop, even though there was no water in the sump pit. The new pump installed very easily and Home Depot said it had a lifetime warrantee. The new pump is at least 1hp, maybe more (I don't recall exact HP) and it pumps water out like a rocket launcher. It's way louder than the old pump and might be overkill for this operation. At the time, I was thinking, bigger is better but didn't consider the noise and vibration factor. Doh!

Good luck,

J

John151 · « **Reply #11 on:** 28 Jul 2011, 03:54 pm »

Major storms again last night. This time we lost power for 3-4 hours.. Luckily we did not get the insane amount of rain as last week and the battery back up pump did the job when the power went out (i.e. dry basement). Not sure what would have happened last week if we had lost power.

More storms forecasted for tonight!

Wayner · « **Reply #12 on:** 28 Jul 2011, 07:07 pm »

Increasing the horse power of the AC pump did nothing to improve your situation. You should have increased the pipe size so that it could pump more water volume. Higher HP pumps are usually required with a long stand pipe, or extra distance for the discharge hose.

The battery back-up is nothing more then a back-up sump and is not intended to run continuous duty. Like your other sump, it probably should be 1 on and 3 off in terms of time intervals. Also with two pumps going thru the same pipe, and running continuously, you are increasing the pressure of the discharge and the small pipe is not able to handle the volume. If you use the regular plastic baffled discharge hose, the baffles actually impede the water's ability to vacate the pump system and also causes a "back up".

So, I would do 2 things. Go to a larger size discharge pipe (will have to change out check valves) and I would use a larger outdoor pipe instead of the flexible black baffle stuff, or at least, use as much straight pipe as possible and also increase the size of the baffle pipe.

As in electricity, less resistance = more volume and less work for the motors.

Or too much input, not enough output.

It reminds me of the highway going thru town here. 2 lane coming in, then goes to 4 lane thru town, then back to 2 lane. results: no change in traffic speed, or volume.

Wayner

TomS · « **Reply #13 on:** 28 Jul 2011, 07:54 pm »

Two years ago I arrived back from spring break vacation to a finished basement listening room with about 8" of water in it, resulting in a total loss of everything I had. It was a very sad day.

The failure mode ran something like this: The primary 1/2hp AC pump (less than 2 years old on a 3 year warranty) failed mechanically. There was NO restriction found on the outlet piping or path to the drain area outside the house. The battery backup pump, even though it supported full duty cycle, not the typical cheapo plastic pumps, DID kick in and quickly ran out of juice since we were not home (within 24 hours). This left us completely unprotected. Water then had its way with our basement.

My insurance company worked through all this with us and did everything possible to make us whole on it. The loss coverage we had is no longer offered generally but we were grandfathered. They then sued the pump company with regard to the warranty and they actually ruled on our behalf (on a $150 pump).

To prevent re-occurance, I consulted with several "experts" in the business. Most had no idea what they were talking about, but I finally happened upon a chap who completely understood my concerns and how far I would go to prevent damaging my equipment again.

I have 3 pumps with 2 independent outlet circuits. There are 2 AC powered pumps, which are identical, in the bottom of the pit, configured with upper (8" higher) and lower slide switches so that if the bottom one fails, the upper one takes over. They do NOT run at the same time unless the bottom one is somehow overwhelmed. They each feed into their own check valve and then join at a Y to the primary outlet. The final component, since we are on city water, is a municipal water pressure powered pump, that is fully capable of supporting the full load all by itself. It uses water for power, so is very wasteful when it runs, but given the alternative of a basement full of water, a couple hundred dollar water bill is a bargain. This has a second totally separate outlet pipe that just dumps a few feet outside the house. Since it should never be running I don't really care if it dumps into the yard for a day or so. I bought mine from Basepump systems http://www.basepump.com/Basepump.htm. It works like a champ and does not depend on AC power or batteries to work. I think I'm finally secure and I don't have to deal with batteries, which are a constant maintenance nightmare in themselves.

The systems you get at the big box stores are basically junk for the most part. I learned the hard way, but was fortunate to have solid insurance coverage and was able to recover fully.

Tom

Wayner · « **Reply #14 on:** 28 Jul 2011, 08:10 pm »

Water powered pumps are great, but not a universal answer (like for those in rural areas) and these are the folks that see the most frequent power outages.

The one thought that I always pondered on was a 250 gallon sump basket. It could run for days into this stupid thing and then use a big ass pump to clear it out.

The sump pump thing is really annoying. "Let's build a boat with a hole in the bottom, only to be saved by electricity, which is known to fail at the time you need it, like in a thunderstorm".

If someone can design a pump that works in a failsafe mode, you will be a fricken millionaire!

Wayner

thunderbrick · « **Reply #15 on:** 28 Jul 2011, 08:12 pm »

When I first moved into my existing house the downspouts ran right into the foundation. We had a spring-time gully washer and we had water FLOWING in the basement. In on the north, out the door on the south. I brought in two truckloads of dirt and built a retaining wall to get the outside water AWAY from the house. We also routed the downspouts into that 4" black corrugated pipe there were buried so they came out 50' downhill from the house. I also installed a sump pump below the concrete that wasn't that big a deal to install if you know which end of a shovel is the handle

. That sump also drains downhill. In the 20 years since I have had one small puddle near the sump, and that was it.

Main thing is, block the water at the source if you can, before the sumps take over.

TomS · « **Reply #16 on:** 28 Jul 2011, 08:56 pm »

Quote from: thunderbrick on 28 Jul 2011, 08:12 pm

When I first moved into my existing house the downspouts ran right into the foundation. We had a spring-time gully washer and we had water FLOWING in the basement. In on the north, out the door on the south. I brought in two truckloads of dirt and built a retaining wall to get the outside water AWAY from the house. We also routed the downspouts into that 4" black corrugated pipe there were buried so they came out 50' downhill from the house. I also installed a sump pump below the concrete that wasn't that big a deal to install if you know which end of a shovel is the handle . That sump also drains downhill. In the 20 years since I have had one small puddle near the sump, and that was it.

Main thing is, block the water at the source if you can, before the sumps take over.

I did most of that when we first bought the house 15 years ago, connected all the downspouts, put in new perimeter drains, etc to collect 50' downhill through hard pipe into a large stone dry well we had built. Most of the time the pump doesn't even run but a few times during the spring thaws the water table must really get up there so it runs for a few days. Then it's quiet for months. Go figure.

thunderbrick · « **Reply #17 on:** 28 Jul 2011, 09:20 pm »

Sounds good! Spring thaw? You live in the Rocky Mountain snowpack?

Mikeinsacramento · « **Reply #18 on:** 28 Jul 2011, 09:31 pm »

Quote from: Wayner on 28 Jul 2011, 08:10 pm

If someone can design a pump that works in a failsafe mode, you will be a fricken millionaire!

The problem isn't the pump, it's the driver. You can run electric off a transfer switch to a generator.

Or drive with an engine.

JLM · « **Reply #19 on:** 28 Jul 2011, 09:42 pm »

Double check valves are needed to insure no backflow from one side of the Y to the other (that's how I plumbed my primary-A/C/lower/submersible and backup/battery/higher/submersible sump pumps with no problems (foundation was block walls - another bad idea in heavy/wet soils).

In my 6 year old house sump and perimeter foundation drains work by gravity (code still required a pump). All 2 foot overhangs with gutters. Downspouts all tie to another gravity drain (foundations are poured concrete).