LP Powered Whole Home Generator

[Firebrick43]

At the day job I have been involved with many 1000 gallon tank installations, and the propane company never installed a drainage system.

They do bed the tank in with sand and they install a cathode protection system.

They also partially fill the tank at install to ensure it won’t float out of the ground.

Maybe they are more interested in selling new tanks down the line?

Since most of our underground installs are in high end additions, that are almost always built in or next to the wooded areas around the rivers and creeks a drain tile to daylight is never a problem as most are built into a hill or a ravine is 50’ aways usually.

We do the bed of sand and two anode bags under the tank and 5 year checks to make sure they are still good.

A tank septic or propane can still float out of the ground if the level gets low and it’s particularly wet. A full propane tank will actually float in water. After Katrina there were hundreds of tanks, many full, that were floating in lake pontchartrain. It’s code in many places now to use screw in anchors with cables to tie them down in flood plains, both below and above

 

[jade97]

I'm only installing the drain for the riser.

 

[mm08822]

Did you ever check the output pressure of the second stage regulator while running under different loads?

 

[Firebrick43]

We condemned an underground put in the 90’s 2 weeks ago. The riser was always damp(but never flooded. It was not one of the tanks we were part of the installation.

The rust on the riser pipe was terrible and pitting depth indicated it would let loose any time. Sort of sad as there was a ravine less than 50’ behind it. Anode bags were good but they can only do so much.

When we go to set a new tank(going to be above ground) I will get pictures.

On the flip side we have on underground that is always bone dry(have to soak the ground for a day with a running hose to do an anode check) that is a 1963 and is still doing great. I don’t think it had anode bags on it either until we made them mandatory, or I should say our insurance made them mandatory.

 

[jade97]

Did you ever check the output pressure of the second stage regulator while running under different loads?

Not since the regulator was replaced.

 

[jade97]

It's been running fine since bailing and digging the trench. Still working on making sure I have the correct pitch...

 

[jade97]

Yard is very sloped. The hill leading down to the tank doesn't help.

Level shown in picture is level.

 

[jade97]

Further down the slope.

 

[jade97]

Who would I want to come look at this? The generator maintenance company? A propane company? It back fired a few times while I'm working on this drainage.

Either way I'm out coin, as the warranty ran out in 2023.

 

[jade97]

Could it have anything to do with humidity?

Load shouldn't be an issue, since it's 38 KW.

 

[Fav Onefour]

Two regulators on that line?

I'm amazed to see so many mention buried tanks. I've never seen one around our region. That also means I've never seen a regulator under water.
That being said, this setup seems to screw up regulators on the dryers.

During cold harvest seasons the regulators often get condensate that drips and freezes around them. They don't fail automatically, but they have short lifespans compared to anything else around the site. Honestly, it seems like we fiddle around with those things way too often. It is tough to diagnose intermittent failures. It's not uncommon to replace one just to see if it works.

That tank also feeds a generator. The setup is less than ideal because of location related to the tank. Must be 1,000 feet of buried line. The generator used to have a dedicated tank but has now been tied into the large system. We did "tweak" the regulator after switching to tank and long line. It has been good for three years.

 

[mm08822]

Two regulators on that line?

I'm amazed to see so many mention buried tanks. I've never seen one around our region. That also means I've never seen a regulator under water.
That being said, this setup seems to screw up regulators on the dryers.

During cold harvest seasons the regulators often get condensate that drips and freezes around them. They don't fail automatically, but they have short lifespans compared to anything else around the site. Honestly, it seems like we fiddle around with those things way too often. It is tough to diagnose intermittent failures. It's not uncommon to replace one just to see if it works.

That tank also feeds a generator. The setup is less than ideal because of location related to the tank. Must be 1,000 feet of buried line. The generator used to have a dedicated tank but has now been tied into the large system. We did "tweak" the regulator after switching to tank and long line. It has been good for three years.

Two is very common.

A high pressure regulator @ the tank to deliver ~10psi from the tank to a second low pressure regulator typically close to point of use @ ~10-12"wc pressure.

Regulator vents are sometimes piped away from the the actual regulator for either water submersion concerns and/or vent too close to combustion sources or inlet vents.

Edit: 1st stage output is 10 psi not 2.

 

[Firebrick43]

Two is very common.

A high pressure regulator @ the tank to deliver ~2psi from the tank to a second low pressure regulator typically close to point of use @ ~10-12"wc pressure.

Regulator vents are sometimes piped away from the the actual regulator for either water submersion concerns and/or vent too close to combustion sources.

The primary/red regulator is 10 psi not 2

 

[mm08822]

Not since the regulator was replaced.

I would check it again at the gen. The regulator at the tank looks very new. I assume that is the one you are referring to.
What about the 2nd one?
How old is it?
Is the vent clear?
Output pressure when gen running?

 

[mm08822]

The primary/red regulator is 10 psi not 2

You're right , I was thinking NG w/2 stages.

 

[Firebrick43]

Who would I want to come look at this? The generator maintenance company? A propane company? It back fired a few times while I'm working on this drainage.

Either way I'm out coin, as the warranty ran out in 2023.

I would have your propane company come out and check pressures, both initial and flow pressure while the genny is runny and you record the results.

It’s insane how many times we get a call that the furnace or generator tech is trying to blame pressures for their problems. First question I have for the home owner is did the tech check the pressures with their own tools and the answer is always no.

We to safety checks for free. We are typically irritated during deep heating seasons when techs play games but right now is a slow time and I personally have no issue stopping and helping a customer nail down a problem

 

[jade97]

I would check it again at the gen. The regulator at the tank looks very new. I assume that is the one you are referring to.
What about the 2nd one?
How old is it?
Is the vent clear?
Output pressure when gen running?

No, the red one at the tank was installed in 2018 when the generator was installed. The upper green regulator was replaced 2023, when the original wouldn't control the pressure....went high, not allowing the gas solenoid to open at start up

 

[mm08822]

Typical UG tank detail.....

 

[mm08822]

No, the red one at the tank was installed in 2018 when the generator was installed. The upper green regulator was replaced 2023, when the original wouldn't control the pressure....went high, not allowing the gas solenoid to open at start up

So need details.......what pressure is the gen seeing NOW both at standstill and while running with various load levels?

Do you have a pressure gauge in the 0 - 30 "WC range? Know how to use it? What is the spec'd operating range of the gen 10 - 12" or...?

When the gen backfires/burps, is it coinciding with a change in electrical load?

 

[jade97]

mm08822, you're in NJ, I'm in Berks Co PA, walking distance to Lehigh Co.....I should pay you to stop by

 

[jade97]

So need details.......what pressure is the gen seeing NOW both at standstill and while running with various load levels?

Do you have a pressure gauge in the 0 - 30 "WC range? Know how to use it? What is the spec'd operating range of the gen 10 - 12" or...?

When the gen backfires/burps, is it coinciding with a change in electrical load?

I can only say when it pops, the lights flicker. It doesn't seem to be load dependent, but I could be wrong.

I did buy a gauge for trouble shooting the bad upper regulator, but I'm not really comfortable f-ing with propane or AC power.

 

[mm08822]

mm08822, you're in NJ, I'm in Berks Co PA, walking distance to Lehigh Co.....I should pay you to stop by

What town?

 

[jade97]

Hereford

 

[wyliesdiesels]

sounds like a service call is in order

 

[Fav Onefour]

Two is very common.

A high pressure regulator @ the tank to deliver ~10psi from the tank to a second low pressure regulator typically close to point of use @ ~10-12"wc pressure.

Regulator vents are sometimes piped away from the the actual regulator for either water submersion concerns and/or vent too close to combustion sources or inlet vents.

Edit: 1st stage output is 10 psi not 2.

I know.
Sometimes just asking a question helps a person take a different look at the problem.

I've been in a few head scratcher situations where I couldn't see the solution. Right in the middle of all the frustration comes along someone with a simple question and the light bulb flashes.

In the end, I bet this one is related to water submersion and the combination of regulators.

 

[mm08822]

mm08822, you're in NJ, I'm in Berks Co PA, walking distance to Lehigh Co.....I should pay you to stop by

You are well over an hour away! Bucks county would be a different story.

You should start with your local LPG supplier. Tell them you want to prove out whether the installed system is delivering the proper pressure and flow.
Need a tech to review the system and put a test gauge at the gen while it runs under various loads.

 

[gmcgeo]

After reading over most of this, My only concern is 10psi first stage with 5/8 copper. By the pictures i see looks to be more then 50' run.

at 50' for 5/8 copper your producing 901,000 btus. While your 38kw gen is asking for 450,000 btus you should be ok. However start up will take max pressure, typically when i size large Generators i take the Btu rating and times it by 3. This would give you a 1.350 mil rating at start up. Seeing that you are getting the gen to start and it runs. I would say your issue is not LP issue. However, i need to know the max run this 5/8 copper is running underground to 2nd stage reg.

 

[jade97]

I will start with the propane company and then the generator company.

Thank you all for your help!

 

[jade97]

Tech was out today to perform the scheduled maintenance. Pressure under load checked out fine. They replaced the plugs (as part of maintenance) and the popping was still observed. The more load, the worse the backfire.

In consultation with someone at his company or Generac, he is stating the issue is probably a bad ignition coil.

I ordered 4 new coils and will replace them as soon as they arrive.

 

[mm08822]

Not sure how difficult it is to rip down the gen to get to the coils on your 38KW, but I would get a pair of these and check first. ( I use 2 when I do PM's for time savings. It saves on shut down/re-positioning time to check the other plug - 2 cylinder units.)

Measure what each existing gap is and what spec is.

 

[jade97]

The coils are relatively easy to get to...same with the plugs.

 

[jade97]

New coils solved the misfire issue.

Is there a way to test old coils to see which one(s) were bad?

 

[mm08822]

Easiest way could have been to change one at time and throw out the offending one. Take ohm readings of each from plug wire to coil lamination. See if any reading is far off from the others. This particular test application is probably better using a megger than an ohm meter.

Maybe find the "oddball" with different readings and put it back in. See if gen starts to misbehave with it installed. Keep 1 or 2, for future just in case. Throw out the rest.

.

 

[jade97]

Coil Cyl #1 primary 1.2 ohms secondary 7 Mohms
#2 p 1.4 ohms s 6.9Mohms
#3 p 1.3 ohms s 6.8 Mohms
#4 p 5.3 ohms s 7.2 Mohms
#4 is probably the problem child