LPG Sensor - Which to use with SeeLevel 2 System?

[trekerboy]

This is a cross-post with a topic I started in a different forum, but since it's sort of bridges that gap between Electrical and "LP Gas, Piping, Tanks & Regulators" topics I thought I'd post here too and let the moderators move or delete it if it's not appropriately categorized...

We're using the SeeLevel 2 Tank Monitoring system (Amazon.com: See LeveL Tank Monitor 709: Automotive) which has the ability to display the remaining level of propane in percent. Our Excella has 2 x 40lb propane tanks connected by a regulator which supplies fuel to all the gas-operated things in the camper.

With all that being said, my question is this: what do I need to be able to monitor the propane tank levels using the SeeLevel 2 panel? Is there supposed to be a sensor on each propane tank? Or is there supposed to be a sensor on the regulator to report the percent full? I see neither in my current setup, so I'll need to buy something to make this work, just not sure what.

1. Do I need something like this Manchester Sender Unit? http://amzn.com/B003D3WPGS. If so, when one tank is empty and I switch to the other, how would the SeeLevel system know to begin monitoring the 2nd tank? Would I have to manually switch the sensor cable from one to another?

2. Or maybe I need a sensor built into the regulator; something like this? Propane Regulator Valves on Sale - PPL Motor Homes. I don't think this exact unit would work for my application since the "sensor" they mention sounds like it's just a light on top of the device itself.

Any advice, or pictures of your setup (with remote level monitoring) would be appreciated, thank you!

[ghaynes755]

The only tanks that I have seen that have the sensors are on the the 2015 Classic. The 40 gal aluminum tanks have a tank level indicator with a sensor mounted on the face. It looks like the Manchester that you show. New AS's use steel tanks which don't usually have the port for a tank gauge. Vintage Trailer sells aluminum tanks with the option of having the gauge at an additional charge.

Might be a good question for See Level.

Here's a link to a shot of the 2015 Classic tanks.

http://colonialairstream.com/2015-ai.../images/38.jpg

[idroba]

In the 70's and 80's it was fairly common for the high end aluminum tank Airstreams to have a propane level indicator built into the tank valve. It had a separate float which operated a lever which turned a magnet on one side of an aluminum separation element. On the other side was either a gauge or a sensor element driven by the magnet. This allowed monitoring without any tank opening.

When the new stile OPD valves were mandated in the 90's unfortunately none were made with the float/magnet/sensor built in. So, anyone with the old single bung tanks was out of luck and had to abandon the gage system, be it dial or electronic.

Newer aluminum tanks such as those shown in the link to the photo above are now available with two bungs, one for the valve, one for the gage/sensor. You can get a gage/sensor as a separate item but must have a 2 bung tank to use it.

There is no new single bung OPD valve and gage sensor unit. None, nada.

So, you cannot have a working electronic gage system anymore unless you are willing to buy new 2 bung tanks and sensors. I would guess the cost of a new pair of tanks and sensors would push $1000 but maybe cheaper, I have never looked.

[Bruce B]

Vintage Trailer Supply has what you need. I too swapped out my useless CatCon system for a SeeLevel system a couple of years ago and ended up with the propane level indicator. The rub for our size trailer was that the 20 lb tanks are not made with gauges so I simply went up to 30 lb tanks and threw away the propane bottle cover. Then I polished the tanks...
My 30 lb tanks were less than $300 each with the gauges I needed for hooking up to the SeeLevel.
Bruce

[trekerboy]

Thanks for the replies everyone. After lots of research and talking to a few different professionals in this sphere, I've confirmed that you can NOT add these types of propane level gauges (also known as "sender units") to tanks that don't already have them installed. The gauges are built into the tanks during the manufacturing process.

Looks like my only option is to ditch my existing, gauge-less tanks and order the units from Vintage Trailer Supply:

40 Lb. (9.4 Gallon) Vertical Aluminum LP Tank

[guskmg]

I just purchased new electrical sender/gauges at Airstream. I have Wothington 40# tanks. IIRC the electrical senders are 90 ohms full-scale.
Also, I have bought them in the past from Propane parts suppliers. Maybe there are some still in inventory if they are no longer available from Worthington.