SeaLevel II, Model 709 Tank Monotor System

SteveG · 01-24-2008, 01:14 PM

I have joined the SeaLevel II installation group. I did not want to remove the OEM tank measuring system so left it in place. Because the One Place panel leaves no significant extra room I initially was going to mount the SeaLevel model 709 display panel in the tank dump compartment. But I noticed that I had a clear access through the adjoining corner of the bathroom wall to the One Place panel so located the display panel at that location. I don't monitor the tank measurement gauges regularly so out of sight is not a problem.

Pulling a cable from the dump compartment to the One Place panel was not as hard as I thought it might be. It took a number of tries to fish a snake from the top to the bottom and the snake was easy to spot and grab through the small squinty vision crack that was available between the top of the tank and the coach underbody after I removed the tank protection panel. The black tank vent stack runs through the One Place wiring space so that helped me locate the snake.

I made up a cable from spare #18 wires I had. I taped four wires together and installed them in a wire loom: 1) spare power wire in case in the future I want to put a display panel in the dump compartment; 2) ground wire; 3) LP gas wire; 4) sending unit wire (the sending units are connected in parallel so just one wire is required back to the display panel.)

I tapped into the One Panel water switch hot side for power. I installed a ground bolt in the dump compartment so it is high enough that the tank protection panel hides it and all the new wiring. I did this ground bolt because the install instructions said to have a common ground for the display panel and the tank mounted senders.

Because my Journey's exterior gray and black tank dimension is 7" (and I am guessing that they are all the same size) and the bottom edge of the tank is rounded, I had to make a sender length decision which I now realize I should have stopped and asked before I completed the installation. I cut the sender to a 6" length and the alternative would have been the minimum length of 4 ½" as you can only cut in 1 ½" segments. I reasoned that maximum sender length would be best. But the rounded bottom tank edge caused me to have to mount the top of the sender within 5/16" of the top tank edge. Since the top tank wall is 3/16" to 1/4" the 5/16" measurement prevents interference and my "P" reading is good at P52 (more about "P" readings below). So everything seems to be working OK. With the sending unit located as it is I was told that 100% will occur when the fluid level reaches the top of the top pad which will mean the tank is absolutely full. Is this good tank management or should I have either cut another pad off or risked mounting the sending unit slightly lower so it was attached to the start of the curve? The factory technician said that he would have done it the same way I did. So when I get the tank full I'll see how it works out.

I followed the instructions pretty close by sanding the two tanks where I installed the sending units and cleaned the sanded spaces with alcohol before installing the senders. I even temporarily taped the senders to be sure they worked correctly before permanently mounting them. But the next time I tape I will only tape the very edges. I taped more then the edge thinking that the masking tape might not hold the board in place. I was very glad that I taped the sending units and highly recommend this step. You need to know that the sending units work correctly before you permanently mount them. Initially my sending units did not look like they were going to work.

Both units (gray & black) seem to measure the tank correctly. The factory tech told me it is the tank height that is being measured not the volume. As my Journey gray and black tanks are pretty close to 7" in exterior depth I cut the SeaLevel sending unit to 6" in length which gives it an effective height of "4" which means there are four 1 1/2" sending pads in each sending unit. This means that each sending pad has the capacity of four reads. So for my 6" sending unit has 4 pads x 4 reads = 16 possible reads. The tank height is thus divided into 16 increments and each segment is considered a percentage of the physical height and displayed in the panel as a percent of the tank height from 0% to 100%: 1-increment=0; 2-increment=6.67%; 3-increment=13.34%; 4-increment=20.01%; etc to 16-increment = 100%. I was told by the factory that there is a 3% error rate and the displayed numbers are rounded to the nearest whole number.

Because the gauges seem to be measuring correctly I moved on to the signal tank penetration test. The installation manual uses an example of "P26" which indicates a 26% tank penetration power. My tank penetration power was "P00". The manual did not discuss what P00 represents. I called my salesperson and here I had some bad luck. He told me it represented zero tank penetration power and something was wrong with the installation. So we spent a while discussing the installation. My installation looked just like the others I have seen in this forum. So nothing he suggested worked so he said he would call the factory. 1 1/2" hours later the answer was that "P00" means maximum tank penetration. So a lot of time was wasted. I re-installed and the "P00" became P52. Go figure!

I took off the masking tape and permanently installed the sending units. Since our tanks are protected by the metal panel I saw no need to further protect the sending units with either a duct tape covering (sales person's idea) or an undercoat covering as discussed in Technical Services Bulletin #19.

Later I called the factory to discuss my installation with a technician and they assured me that my work sounded correct and further assured me that after I took a few trips filling and emptying the tanks that if the sending units were not working correctly they would replace them.

I have not yet tried to hook up the LP tank or the fresh water tank. I was not able to find a way to snake the wiring across the "interior" tank space. So I wired it underneath through the exterior automotive part. If I would give up the OEM installation I could re-use those wires. But the OEM water and LP tank gauges are not my big gripe as they measure close enough. So I am keeping the One Place panel original and the OEM system as a back up. Who knows maybe someone will come up with a miracle cure for cleaning the tank innards!

I am hoping the SeaLevel gauges will provide an accurate measurement for the black and gray tanks to help provide better trip management. We'll see what happens next weekend as we will roll for a long weekend camping.

I have attached a couple of photos of the installation:

The Beginning:

Black tank sending unit taped in place

Ground bolt

Black tank sending unit completed

Gray tank sending unit completed

Display panel cutout seen through One Space opening

Display panel mounted in bathroom wall

SteveG · 01-24-2008, 01:14 PM

I have joined the SeaLevel II installation group. I did not want to remove the OEM tank measuring system so left it in place. Because the One Place panel leaves no significant extra room I initially was going to mount the SeaLevel model 709 display panel in the tank dump compartment. But I noticed that I had a clear access through the adjoining corner of the bathroom wall to the One Place panel so located the display panel at that location. I don't monitor the tank measurement gauges regularly so out of sight is not a problem.

Pulling a cable from the dump compartment to the One Place panel was not as hard as I thought it might be. It took a number of tries to fish a snake from the top to the bottom and the snake was easy to spot and grab through the small squinty vision crack that was available between the top of the tank and the coach underbody after I removed the tank protection panel. The black tank vent stack runs through the One Place wiring space so that helped me locate the snake.

I made up a cable from spare #18 wires I had. I taped four wires together and installed them in a wire loom: 1) spare power wire in case in the future I want to put a display panel in the dump compartment; 2) ground wire; 3) LP gas wire; 4) sending unit wire (the sending units are connected in parallel so just one wire is required back to the display panel.)

I tapped into the One Panel water switch hot side for power. I installed a ground bolt in the dump compartment so it is high enough that the tank protection panel hides it and all the new wiring. I did this ground bolt because the install instructions said to have a common ground for the display panel and the tank mounted senders.

Because my Journey's exterior gray and black tank dimension is 7" (and I am guessing that they are all the same size) and the bottom edge of the tank is rounded, I had to make a sender length decision which I now realize I should have stopped and asked before I completed the installation. I cut the sender to a 6" length and the alternative would have been the minimum length of 4 ½" as you can only cut in 1 ½" segments. I reasoned that maximum sender length would be best. But the rounded bottom tank edge caused me to have to mount the top of the sender within 5/16" of the top tank edge. Since the top tank wall is 3/16" to 1/4" the 5/16" measurement prevents interference and my "P" reading is good at P52 (more about "P" readings below). So everything seems to be working OK. With the sending unit located as it is I was told that 100% will occur when the fluid level reaches the top of the top pad which will mean the tank is absolutely full. Is this good tank management or should I have either cut another pad off or risked mounting the sending unit slightly lower so it was attached to the start of the curve? The factory technician said that he would have done it the same way I did. So when I get the tank full I'll see how it works out.

I followed the instructions pretty close by sanding the two tanks where I installed the sending units and cleaned the sanded spaces with alcohol before installing the senders. I even temporarily taped the senders to be sure they worked correctly before permanently mounting them. But the next time I tape I will only tape the very edges. I taped more then the edge thinking that the masking tape might not hold the board in place. I was very glad that I taped the sending units and highly recommend this step. You need to know that the sending units work correctly before you permanently mount them. Initially my sending units did not look like they were going to work.

Both units (gray & black) seem to measure the tank correctly. The factory tech told me it is the tank height that is being measured not the volume. As my Journey gray and black tanks are pretty close to 7" in exterior depth I cut the SeaLevel sending unit to 6" in length which gives it an effective height of "4" which means there are four 1 1/2" sending pads in each sending unit. This means that each sending pad has the capacity of four reads. So for my 6" sending unit has 4 pads x 4 reads = 16 possible reads. The tank height is thus divided into 16 increments and each segment is considered a percentage of the physical height and displayed in the panel as a percent of the tank height from 0% to 100%: 1-increment=0; 2-increment=6.67%; 3-increment=13.34%; 4-increment=20.01%; etc to 16-increment = 100%. I was told by the factory that there is a 3% error rate and the displayed numbers are rounded to the nearest whole number.

Because the gauges seem to be measuring correctly I moved on to the signal tank penetration test. The installation manual uses an example of "P26" which indicates a 26% tank penetration power. My tank penetration power was "P00". The manual did not discuss what P00 represents. I called my salesperson and here I had some bad luck. He told me it represented zero tank penetration power and something was wrong with the installation. So we spent a while discussing the installation. My installation looked just like the others I have seen in this forum. So nothing he suggested worked so he said he would call the factory. 1 1/2" hours later the answer was that "P00" means maximum tank penetration. So a lot of time was wasted. I re-installed and the "P00" became P52. Go figure!

I took off the masking tape and permanently installed the sending units. Since our tanks are protected by the metal panel I saw no need to further protect the sending units with either a duct tape covering (sales person's idea) or an undercoat covering as discussed in Technical Services Bulletin #19.

Later I called the factory to discuss my installation with a technician and they assured me that my work sounded correct and further assured me that after I took a few trips filling and emptying the tanks that if the sending units were not working correctly they would replace them.

I have not yet tried to hook up the LP tank or the fresh water tank. I was not able to find a way to snake the wiring across the "interior" tank space. So I wired it underneath through the exterior automotive part. If I would give up the OEM installation I could re-use those wires. But the OEM water and LP tank gauges are not my big gripe as they measure close enough. So I am keeping the One Place panel original and the OEM system as a back up. Who knows maybe someone will come up with a miracle cure for cleaning the tank innards!

I am hoping the SeaLevel gauges will provide an accurate measurement for the black and gray tanks to help provide better trip management. We'll see what happens next weekend as we will roll for a long weekend camping.

I have attached a couple of photos of the installation:

The Beginning:

Black tank sending unit taped in place

Ground bolt

Black tank sending unit completed

Gray tank sending unit completed

Display panel cutout seen through One Space opening

Display panel mounted in bathroom wall

Joe-K · 01-24-2008, 02:33 PM

Steve,

Great job on the installation!

We really liked the SeeLevel in our Journey and will be installing a system in our new rig as well. It's a great system that I'd like to see all the OEM's install straight from the factory.

Y-Guy · 01-24-2008, 02:49 PM

Great write up and thanks for the photos!!!

John_Canfield · 01-24-2008, 03:02 PM

Thanks for taking considerable time to document your installation - you are greatly contributing to the knowledge base of the forum!

While reading through your installation, I had a bit of an epiphany - since the system is basically reading the liquid level in the tank based on the sensor tape, the reading will not be linear unless the tank is a box or rectangle.

The tanks are probably irregularly shaped and if the system reads 25% full, that doesn't necessarily equate to .25 times tank capacity unless there is a calibration routine.

Is there such?

On our last boat, the diesel tank was rectangular shaped except for a wedge shape at the bottom. It was fairly simple to calculate the tank volume of a complex shape, but measuring the level of diesel took a little more work. I created a calibrated stick based on lots of fueling data. If the stick was at 25" of fuel remaining and we took 50 gallons to top it off, that became a mark on the stick. Fortunately we had a direct path from the fill to the tank bottom.

Too bad it isn't that easy for our tanks.

SteveG · 01-25-2008, 04:47 AM

John, I looked at the Journey's plumbing drawings and the tank design shows the black tank as a rectangle and the gray tank a rectangle shaped like a "T" with the standing leg of the T pointing to the rear of the MH. So it appears that the Journey's tanks are at least height wise regularly shaped.

I initially thought that the Sealevel gauges would probably not be able to read linear because in my case they are mounted higher off the bottom of the tank then they are off the top of the tank. But with their described technology that may not be a problem And even if is, I do not think that is a worry as it is a relative measure. Once I establish what constitutes "full" then that will become my full mark. Because the top of the sending unit is so close to the top of the tank 90% may be all I can push into the tank.

But as mentioned, it may be a none issue as the SeaLevel install manual says in Chapter 2, System Description, the sender "...auto calibrates itself so that it can read from empty to full regardless of the height of the tank." And there is no manual or recalibration required. Further, "...it is almost impossible for the system to indicate an incorrect water level..." Then in chapter 6, paragraph 15, "Note that the system "learns" about the characteristics of the tank with use, so the readings may be inaccurate when the tank is empty or almost empty when the system is first tested. Once the tank has been filled as least 1/4 full the system will be properly "taught" and should read correctly after that."

The factory tech told me that the system has a digital design that borders on artificial intelligence. I thought that was a bit much but he said that with respect to the systems ability to "learn" about the tank. His statement sounds like hyperbole but the proof will be in the filling and emptying. Based on others experience I am expecting the gauge to measure pretty accurately.

The sales person told me this is similar technology used to measure the volume of crude oil off loaded from ships. Apparently there were at one time some unscrupulous Captains that would off load 90% and keep the other 10% for selling to others later. Don't know if that is a sea pirate story or not....

John_Canfield · 01-25-2008, 08:09 AM

Interesting story Steve. I suppose it really doesn't matter if a 50% reading doesn't mean you have exactly 40 gallons left in an 80 gallon tank.

Let us know how the system does after you have some experience with it.

There is (or was) a tank monitoring system designed for the marine market (think it's called the Tank Tender) that would read any volume tank. To make a reading you had to pull/push (pump) a knob to pressurize the system and that somehow equated into a tank level measurement.

I never did understand how it worked and never really took the time to figure it out since it was expensive and we weren't in the market for such.

Harry B · 01-25-2008, 08:20 AM

Steve, Nice write up and pictures.

I was considering another make out there (Catcon) that measures the weight of the liquids to determine the tank levels. Catcon at Catconproducts.com like SeeLevel has been around for a while and is used as OEM equipment by other RV brands. Catcon is supposed to come out with a new continues display LCD panel, which is what I am holding out for. It appears that SeeLevel's manufacturer has a continues display version available as well but I can't justify their price difference for that feature.

I have the same concerns John has with irregular tank sizes. An additional concern that I have is regarding the shallow tanks that we have in our coaches. It may require the coach to be pretty well level to get an accurate reading with the SeeLevel system specially with reading increments of 7%.

Have you found this to be an issue or am I concerning myself about non issues and should just go ahead with the purchase of a SeeLevel system?

Fakrwee · 01-25-2008, 08:41 AM

Great writeup Steve. On my last big trip to Alaska we did a lot of dry camping and it was frustrating trying to second guess the readouts. When I got back I swore I was going to install the Sealevel. Time went by and it fell back on the list of to do's. Your writeup motivated me again.

Tom

John_Canfield · 01-25-2008, 01:19 PM

<BLOCKQUOTE class="ip-ubbcode-quote"><div class="ip-ubbcode-quote-title">quote:</div><div class="ip-ubbcode-quote-content">Originally posted by Fakrwee:
Great writeup Steve. On my last big trip to Alaska we did a lot of dry camping and it was frustrating trying to second guess the readouts. When I got back I swore I was going to install the Sealevel. Time went by and it fell back on the list of to do's. Your writeup motivated me again.

Tom </div></BLOCKQUOTE>Ditto for us Tom - the tank resolution or accuracy isn't an issue unless we are dry camping, then it becomes a big deal.

Harry - the Catcon system is most intriguing and would be my preference in terms of technical design, but there isn't the track record of the SeeLevel, at least with the DIY folks.

Randy Chesnutt · 01-26-2008, 05:50 AM

I enjoyed reading your artical. I'm ready to go and purchase me one. I want need there instruction I got yours. One thing about it done make know differents what shape your tanks are when your say full you know where the level is , because you put it in and it's time to pull the valve. Great job. Thank you

Gary CA · 01-26-2008, 10:26 PM

Steve: Good install and pictures.

You mentioned you have not hooked-up the fresh water tank. I found access to the top of the fresh water tank by running a wire behind the water pump. The pipes to the tank in my coach are a straight shot to the tank from the water pump. I reached the side of the tank via access panel infront of the tank at the exterior dump valve. Remove some styrofoam and you can reach the top of the tank for the monitor strip.

Good luck with your project, looks good.

SteveG · 01-28-2008, 04:49 PM

Gary, thanks for the feedback. I am familiar with both the water pump and the hatch access to the water tank. I had a joint leak where the 90 degree fitting attaches to the water tank that allows the tank to be emptied. The fix was easy (after I got some help from forum member RedT) in that I just had to tighten the joint after I emptied the tank and removed the tank cover. So I am familiar with that territory. I just can not spot an upper internal clear path between the tank and the dump compartment and there may not even be one. In the end I don't think it's a problem as I have already run the wire in a wire loom through the cable trough along the frame rail and tied it off at the tank waiting until I have got the time to install the sending unit etc.. I'll probably find a place above the tank access hatch to drill a wire entry hole. I'll re-post when this water tank installation is completed.

SteveG · 02-04-2008, 01:59 PM

I can now report that I observed through the toilet exhaust pipe the black tank filled and the SeaLevel II gauge reported 100%. I emptied it and the gauge reported 0%. I filled the gray tank until the gauge said 100% and it did not overfill but it is not possible to observe that the tank is actually filled. But given that both sender units were installed in the same manner the gray tank must also be reporting a full tank. I am confidant that the new SeaLevel II gauge will at last keep me informed as to the tanks fill status.

Joe-K · 02-04-2008, 02:43 PM

Steve,

If I understand you issue with the freshwater tank, you need to find a wiring path from the freshwater tank near the access panel to the dump compartment.

When I installed the SeeLevel 709 in our Journey 36G, I found a path inside the coach that may work for you.

In the second PS storage bay, you should be able to see the freshwater gravity fill hose run across the to of the compartment and down to the water tank. That hose follows a path from the tank up through a hole cut in the floor into a cupboard in the kitchen. By removing the bottom drawer in the kitchen you can fish the wire into the Kitchen, then run it rearward underneath the shower.

Remove the inspection panel under the shower base, and you can feed teh wire down on top of the black and grey tanks where it is pretty easy to fish it over to the dump compartment.

I used that crossover route above the tanks for quite a bit of wiring including that of the macerator system in the dump bay.

SteveG · 02-04-2008, 05:32 PM

Thanks JoeK. I'll check that path. I found the path up to the bottom drawer but did not see the one to the shower. Thanks for the assistance.

SteveG · 02-12-2008, 05:07 PM

The Freshwater Tank sending unit installation is now complete. I choose not to attempt to measure the entire fresh water tank depth. The overall tank on our 2004 Journey 36G measures approximately 16" tall. The irregular part of the tank where I mounted the single 12" sending unit is approximately 14" tall but the water exit fitting takes up the bottom 1 1/2" of that space. That leaves 12 1/2" to mount the sending unit. So the bottom of the sending unit is setting on the top of the water exit pipe fitting leaving about a 1/2" margin space at the top of this irregular tank section. If the entire tank height needed to be read, a second sending unit would be required; for a tank installation similar to our Journey it would be mounted behind the tank drain valve. Other forum members have successfully completed this type installation.

The Winnebago OEM gauge reads the tank in 1/3 increments. The SeaLevel II 12" sending unit has 8 pads x 4 reads per pad = 32 possible reads. The tank height is thus divided into 32 increments and each segment is considered a percentage of the physical height and displayed in the panel as a percent of the tank height from 0% to 100%: 1-increment=0; 2-increment=3.23%; 3-increment=6.46%; 4-increment=9.69%; etc to 32-increment = 100%. Each increment equals a 3/8" space. I was told by the factory that there is a 3% error rate and the displayed numbers are rounded to the nearest whole number.

What I think this all means physically is that the single SeaLevel II gauge will show empty on my tank when the water level reaches the top of the water exit pipe which is the bottom of the gauge. It will show 100% (full) when the water level reaches 14" deep. It will not read the upper 2" of tank space. When the tank is physically full the SeaLevel II gauge will show 100% until enough water is drained so the water level reaches the top of the sending unit. This also means that when filling the tank the SeaLevel gauge will report the tank full at 100% when there is actually still 2" of tank space remaining. But it is not the filling that concerns me; it is the emptying. And now I will have a gauge that will measure the available water more accurately.

I have attached a couple of photos of the installation:

Top of irregular shaped fresh water tank

Bottom of sending unit

Top of sending unit

External wiring installed. Others have been able to fish wiring across the top of teh gray and black tanks internally. I was not able to do that.
http://www.irv2.com/photopost/data/2..._installed.jpg

Completed installation

SteveG · 02-19-2008, 12:52 PM

A freshwater tank followup: The SeaLevel II gauge read 41% when I installed it. That represented the tank water level at instalaltion. I filled the tank today to 95%. At 41% the OEM guauge initally read 2/3 full; at 95% the OEM gauge read 2/3 full.

From 41% to 95% was illustrated on the display in 3% intervals. From 41% to 95% is eighteen 3/8" intervals or the water level of the tank rose about 6 3/4". Next time I'll fill it to 100% to see if that tips the OEM guage to "Full."

Anyway, it's a little easier now for me to manage my water tank with the additional and more specific information.