MEP 802A Aux fuel tank option

[MrShawn305]

Hey everyone, I was MIA for a while there. Had alot going on around here and just haven't had time to be on the web. I finally got some time this week to mess around with my 802a fuel setup and was able to come up with a solution.

So a local guy near me deals in scrap and vehicle dismantling. He had a square (more rectangular, actually) fuel tank off of either a school bus or a box truck. It has the mounting hardware still on it and everything, makes for a great skid or surface to mount/weld to. So here is the part I was struggling with for a long time: How to interface the -5 (5/16" JIC) on the gen to the 1/2" compression fitting on the aux fuel tank pickup.

I pulled the fuel pickup tube out of the fuel tank and started looking at it closely. It appears to be a 3/8" NPT with a dip tube brazed into it. So I took my aux hose and the pickup tube down to my local hydraulics shop and showed them what I have and what I need. After a few minutes of brainstorming and looking at our various options, I said "what if I cut this tube off and braze it onto a new fitting?". He looked at it and said that he could probably remove it there and try brazing it if I wanted. I said let's try it. So he had a 3/8" NPT to 5/16" JIC elbow in stock and sure enough was able to unbraze the dip tube from the old fitting and braze the tube to the new one. He also has what he needed to make me a fuel hose for it to go from JIC to JIC in whatever length I wanted. So now I have a ~50 gallon aux tank that is easily hooked up and requires no modification to the generator. Also, I don't have a whole bunch of different fittings trying to adapt one thing to the other that could potentially leak. I'll add some photos later today or this weekend as I don't plan to install it for another week or so. I need to change out the aux fuel/no fuel switch in the tank.

I figure this is a cheap (tank cost me $60 and the hose/brazing/fitting cost me $20 and some change) option for people wanting to get a multi day capacity fuel tank for their gen without having a drum sitting near it. These are DOT rated and designed for fuel, they have the correct venting and should be pretty resistant to water ingress.

 

[kloppk]

For those looking for a mate to the Aux Fuel inlet.. ---> Aux Fuel Fitting

 

[MrShawn305]

For those looking for a mate to the Aux Fuel inlet.. ---> Aux Fuel Fitting

They actually had those at the shop. They put two of those, the hose and brass "collars" (I don't recall the proper name) and crimped them in the hose machine. Got it made up really nice for less than two of those on Amazon.

 

[cuad4u]

The male fitting on the Facet fuel pump is either 1/8 or 1/4 male pipe threads. Install a brass 3/8 hose barb to it. Ditto on your fuel tank. Install a 3/8 fuel hose between the fuel tank and the Facet fuel pump. Fasten the hose with a SS worm clamp on each end. I guess you could use 5/16 fuel hose. This is exactly how I connected a 100 gallon fuel tank to my 003A and a 40 gallon fuel tank to my 002A. If I missed your point, sorry for my post.

 

[69birdman]

Hey everyone, I was MIA for a while there. Had alot going on around here and just haven't had time to be on the web. I finally got some time this week to mess around with my 802a fuel setup and was able to come up with a solution.

So a local guy near me deals in scrap and vehicle dismantling. He had a square (more rectangular, actually) fuel tank off of either a school bus or a box truck. It has the mounting hardware still on it and everything, makes for a great skid or surface to mount/weld to. So here is the part I was struggling with for a long time: How to interface the -5 (5/16" JIC) on the gen to the 1/2" compression fitting on the aux fuel tank pickup.

I pulled the fuel pickup tube out of the fuel tank and started looking at it closely. It appears to be a 3/8" NPT with a dip tube brazed into it. So I took my aux hose and the pickup tube down to my local hydraulics shop and showed them what I have and what I need. After a few minutes of brainstorming and looking at our various options, I said "what if I cut this tube off and braze it onto a new fitting?". He looked at it and said that he could probably remove it there and try brazing it if I wanted. I said let's try it. So he had a 3/8" NPT to 5/16" JIC elbow in stock and sure enough was able to unbraze the dip tube from the old fitting and braze the tube to the new one. He also has what he needed to make me a fuel hose for it to go from JIC to JIC in whatever length I wanted. So now I have a ~50 gallon aux tank that is easily hooked up and requires no modification to the generator. Also, I don't have a whole bunch of different fittings trying to adapt one thing to the other that could potentially leak. I'll add some photos later today or this weekend as I don't plan to install it for another week or so. I need to change out the aux fuel/no fuel switch in the tank.

I figure this is a cheap (tank cost me $60 and the hose/brazing/fitting cost me $20 and some change) option for people wanting to get a multi day capacity fuel tank for their gen without having a drum sitting near it. These are DOT rated and designed for fuel, they have the correct venting and should be pretty resistant to water ingress.

I used a 45 gallon tank, I got a pair of them for $90

 

[MrShawn305]

The male fitting on the Facet fuel pump is either 1/8 or 1/4 male pipe threads. Install a brass 3/8 hose barb to it. Ditto on your fuel tank. Install a 3/8 fuel hose between the fuel tank and the Facet fuel pump. Fasten the hose with a SS worm clamp on each end. I guess you could use 5/16 fuel hose. This is exactly how I connected a 100 gallon fuel tank to my 003A and a 40 gallon fuel tank to my 002A. If I missed your point, sorry for my post.

Was just documenting what I did in my particular case to give others ideas who may be wanting to add a tank to their unit. Your idea is great too, I was just trying to accomplish it with minimal modification to the tank/lines and no modification to the genset in case I never need to hook up a different tank. Trying to keep it simple, you know?

 

[MrShawn305]

I used a 45 gallon tank, I got a pair of them for $90
View attachment 824531

Ahh that looks good! I'd have jumped on that one! I actually found out last night my tank is a 35 gallon. But still plenty for my 802a with as few outages as we get here. I still have a 55 gallon drum in the garage and a 100 gallon transfer tank in the truck if I need more. I like how you painted it to match, or did it come painted? Any idea what they are from?

 

[MrShawn305]

Here are a couple of photos of my tank and lines for reference. I have not installed it yet as I am waiting on a new fuel level switch for my unit.

 

[MrShawn305]

Also, First Call sent me the wrong filter for a transfer tank and it got me thinking. Has anyone considered installing a filter between the aux tank and the genset? I got to looking and it wouldn't cost much at all to do. Amazon has the Wix 24770 filter base for $30 which will mate to a Wix 33674/33528 or Cat 1R-0749/1R-0750 filters. Both filters are 2 micron with the 33674/1R-0749 being almost 3" longer. Dirty diesel is a good way to bring the unit offline at a bad time in my opinion.

I'm considering ordering the filter base and heading back down to the hydraulics shop to get NPT to JIC fittings for the base, as well as a short hose made up to go from the tank to the filter. I'll weld a piece of angle or square tube I have laying around to the tank brackets and mount it on the inside. Should cost me less than $75 once it's all said and done.

Parts list:
Filter Base: Wix 24770
Fuel Filter: Wix 33674 or 33528
Fittings: NPT to 5/16 JIC if keeping factory, or whatever your setup calls for.
Hoses: short hose to go from fuel tank to filter inlet. Existing aux hose then connects from filter outlet to genset.

 

[WWRD99]

Also, First Call sent me the wrong filter for a transfer tank and it got me thinking. Has anyone considered installing a filter between the aux tank and the genset? I got to looking and it wouldn't cost much at all to do. Amazon has the Wix 24770 filter base for $30 which will mate to a Wix 33674/33528 or Cat 1R-0749/1R-0750 filters. Both filters are 2 micron with the 33674/1R-0749 being almost 3" longer. Dirty diesel is a good way to bring the unit offline at a bad time in my opinion.

I'm considering ordering the filter base and heading back down to the hydraulics shop to get NPT to JIC fittings for the base, as well as a short hose made up to go from the tank to the filter. I'll weld a piece of angle or square tube I have laying around to the tank brackets and mount it on the inside. Should cost me less than $75 once it's all said and done.

Parts list:
Filter Base: Wix 24770
Fuel Filter: Wix 33674 or 33528
Fittings: NPT to 5/16 JIC if keeping factory, or whatever your setup calls for.
Hoses: short hose to go from fuel tank to filter inlet. Existing aux hose then connects from filter outlet to genset.

As long as your aux pump can pull it through it won't hurt having extra filter capacity...maybe a priming ball to get it going or a cheap carb 6lb electric pump if need be...they are cheap...can run the pump off the aux pump wiring so when it turns on it'll turn on the filter pump too. Dig the truck tank idea.

 

[Chainbreaker]

While you are waiting for your fuel level switch you should consider whether you want to do a "full service clean" of the inside of the tank and then line it with something like RedKote or similar. Now is the best time and you will thank yourself a few years down the road.

Today's biodiesel laden fuel can do harm to various bare metals if not compatible with biodiesel. If there is a vent tube you can attach to, you should also consider a desiccant beaded type filter to remove any moisture out of the air before it enters the tank.

 

[MrShawn305]

As long as your aux pump can pull it through it won't hurt having extra filter capacity...maybe a priming ball to get it going or a cheap carb 6lb electric pump if need be...they are cheap...can run the pump off the aux pump wiring so when it turns on it'll turn on the filter pump too. Dig the truck tank idea.

I will do a little more research and see if it is needed. The fuel filter is rated to flow 12-15GPM so I doubt it would be an issue. My friend has a transfer pump pulling through a filter on his tank and it doesn't seem to struggle at all. But if it does need it, I like your idea.

 

[MrShawn305]

While you are waiting for your fuel level switch you should consider whether you want to do a "full service clean" of the inside of the tank and then line it with something like RedKote or similar. Now is the best time and you will thank yourself a few years down the road.

Today's biodiesel laden fuel can do harm to various bare metals if not compatible with biodiesel. If there is a vent tube you can attach to, you should also consider a desiccant beaded type filter to remove any moisture out of the air before it enters the tank.

Not a bad idea. I do live in a very dry climate and I pay attention to the fuel I buy, avoiding bio like the plague. I just don't care for it. The aux tank has already been cleaned and is ready to be put into service.

 

[WWRD99]

I will do a little more research and see if it is needed. The fuel filter is rated to flow 12-15GPM so I doubt it would be an issue. My friend has a transfer pump pulling through a filter on his tank and it doesn't seem to struggle at all. But if it does need it, I like your idea.

I doubt the filter will be much resistance then at that flow rate...the tank is 5 gallons I think on the 802 so it doesn't take much....just thinking of keeping it primed or getting it that way...you'll know once the genset calls for fuel! Mine is gravity so I haven't had any problem feeding the beast.

 

[MrShawn305]

I doubt the filter will be much resistance then at that flow rate...the tank is 5 gallons I think on the 802 so it doesn't take much....just thinking of keeping it primed or getting it that way...you'll know once the genset calls for fuel! Mine is gravity so I haven't had any problem feeding the beast.

It shouldn't matter though as the aux pump only fills the day tank. So even if it loses it's prime, it will just reprime. Only has to go through 6' of hose anyway. I believe the pump as an internal check valve as well.

What set are you running? And what tank setup?

 

[WWRD99]

It shouldn't matter though as the aux pump only fills the day tank. So even if it loses it's prime, it will just reprime. Only has to go through 6' of hose anyway. I believe the pump as an internal check valve as well.

What set are you running? And what tank setup?

I have a 803 with 2 275 gallon home heating oil tanks feeding it...they have the drain at the bottom so I hooked to that with a shut off and filter then steel line to the genset...works great.

 

[MrShawn305]

Ahhh yea that might feed it for a day or two!

 

[cuad4u]

Attached is my 003A with a military surplus 100 gallon aux SS tank. This tank with the built in 13 gallon tank gives almost 5 days running without refueling. I used two brass hose barb fittings, 7 feet of 3/8 fuel hose from NAPA and two SS worm clamps. Total cost was less than $15. I added a 24 gallon aux tank on my 002A the same way. I live in the middle of a large farm. The power line from the highway to my house is more than a mile long. I ran my 003A non stop to provide power to my house for 96 hours during the last hurricane. There is more than 15 inches spacing between the 100 gallon tank and the cooling air fan on the front of the 003A.

I know the Facet fuel pumps used on the 002A and 003A generators are rated to operate constantly, but it concerned me that the aux fuel pump ran constantly even though it is only used a few minutes every 12 hours to refill the on board fuel tank. While the aux fuel pump runs constantly the float switch on the on board tank operates a solenoid only a few minutes every 12 hours to fill the on board tank. I do not know the amp rating of the float switch so I added a relay with a coil rating of 24V and 0.1 amp. This relay is operated by the float switch in the on board tank. This relay operates the solenoid AND the aux fuel pump only when the float switch in the on board tank calls for fuel to refill the on board tank twice a day. IMO this will reduce wear and tear on the $258 aux fuel pump by only operating when needed which is only a few minutes twice a day and it keeps the aux fuel pump from running constantly.

for 96 hours during the last hurricane.

 

[MrShawn305]

I like it, that's a nice fuel tank. I should look into something that size for my 805

 

[Chainbreaker]

...I know the Facet fuel pumps used on the 002A and 003A generators are rated to operate constantly, but it concerned me that the aux fuel pump ran constantly even though it is only used a few minutes every 12 hours to refill the on board fuel tank. While the aux fuel pump runs constantly the float switch on the on board tank operates a solenoid only a few minutes every 12 hours to fill the on board tank. I do not know the amp rating of the float switch so I added a relay with a coil rating of 24V and 0.1 amp. This relay is operated by the float switch in the on board tank. This relay operates the solenoid AND the aux fuel pump only when the float switch in the on board tank calls for fuel to refill the on board tank twice a day. IMO this will reduce wear and tear on the $258 aux fuel pump by only operating when needed which is only a few minutes twice a day and it keeps the aux fuel pump from running constantly.

I may be wrong, but I didn't think the Aux fuel pump, as it pertains to -002a/-003a, actually "runs constantly". I believed that its "powered up all the time" but its only activated to pump fuel when it loses pressure (loses prime) due to the float switch in day tank being activated which triggers opening Aux input valve attached to Aux pump. When solenoid is activated it opens the input side of Aux Pump Solenoid allowing fuel to flow through and then the Aux fuel pump needs to maintain its prime & pressure and is activated as long as the Aux input valve is open. Even if it were to pump a stroke-or-two now & then when not called into actual pumping mode that's probably beneficial for the pump to keep pump internals from sticking.

If that's not how it works I would really like to know.

I usually don't set control panel switch to run my unit in Aux/Run mode unless I am running for extended hours or I know day tank is nearing the 1/4 mark. I once had the day tank fuel level switch float stick in the low position and it overflowed day tank.