Thread: Diesel fuel life in a standby generator

I've been servicing standby gensets for 15 years, and I've seen diesel that has tested up fine after 5 and 10 years. The oldest fuel I've seen test up well was some fuel oil that had been sitting in an underground tank, 5 stories below a high rise in Melbourne that had been there for 30 years. the gensets ran fine on it and could take full load without issue. If you keep the tank full, so no condensation forms in it, it will last for years.

From memory the book for the gensets that form up part of the field power distrribution system reccomedn that if the fuel isnt going to be used in 6 months that it be drained and replaced. however the onboard tanks are quite small and generally rely on daily refueling or 44 gallon drum feeders.

Originally Posted by bacicat

I've been servicing standby gensets for 15 years, and I've seen diesel that has tested up fine after 5 and 10 years. The oldest fuel I've seen test up well was some fuel oil that had been sitting in an underground tank, 5 stories below a high rise in Melbourne that had been there for 30 years. the gensets ran fine on it and could take full load without issue. If you keep the tank full, so no condensation forms in it, it will last for years.

Thanks.......

12 months should be fine......I might even bump it out to two years. It to protect out environmental licence to operate of which is under scrutiny ATM the last thing we need is the generator not start due to dodges fuel.....don't think the authorities will see the funny side of it.

Are you any good at sizing a generator........two companies I have approached both suggest ed a 60kva but when our electricians questioned it one of them bumped it up to an 88kva which seems about right. The maths should be straight forward, would have thought the sales guys would have been all over it but they have given me little confidence.

Just I case you are

2 x 16kW submersible pumps
Max. running current 32amps
Soft start (currently DOL)
Delayed start I.e. One starts than the other

Weeds arse is on the line next time we discharge exceeding our licence agreement

I have the same figure as Blknight. My figure is from my RAN experience.

Originally Posted by Blknight.aus

From memory the book for the gensets that form up part of the field power distrribution system reccomedn that if the fuel isnt going to be used in 6 months that it be drained and replaced. however the onboard tanks are quite small and generally rely on daily refueling or 44 gallon drum feeders.

Thanks Dave...........the frequency doesn't overly bother us, by the sounds of it I could just transfer it into a forklifts/skid steer loaders

Originally Posted by weeds

Thanks.......

12 months should be fine......I might even bump it out to two years. It to protect out environmental licence to operate of which is under scrutiny ATM the last thing we need is the generator not start due to dodges fuel.....don't think the authorities will see the funny side of it.

Are you any good at sizing a generator........two companies I have approached both suggest ed a 60kva but when our electricians questioned it one of them bumped it up to an 88kva which seems about right. The maths should be straight forward, would have thought the sales guys would have been all over it but they have given me little confidence.

Just I case you are

2 x 16kW submersible pumps
Max. running current 32amps
Soft start (currently DOL)
Delayed start I.e. One starts than the other

Weeds arse is on the line next time we discharge exceeding our licence agreement

Yep, I size gensets as part of my current job.

A 60KVA would work, but it is the smallest unit that would do the job and would grunt getting the second motor away. The 88KVA is a much better choice - your Electrician was right to do that. Sales guys don't know as much as they think sometimes.... I am one now.... But I'm also a qualified Sparky who's been working only on gensets - both on and off the tools - for the last 18 years.

Oh, do you know what type of excitation the machine will have? There are 2 types - shunt and PMG. PMG excitation will give much better motor starting characteristics than a standard shunt excited unit. It will cost you another grand or so to go that way though. Also, some soft starters have issues with frequency changes like you see on a genset when a load is applied. It would pay to check the minimum and maximum frequency the starters will work at. VSD's work better off smaller genset supplies such as this.

the couple of times that I've had to setup FPDS and similar for prolonged standby some smart grease monkey usualy comes along with a valve to fit to the drain on the tank, a 44 with some custom bungs on it and a delivery nozzle for a gravity feed hose.

the 44 gets laid down on top of the genny, the delivery hose attaches to the small bung and sits at the bottom

the big bung has 3 ports on it and it goes uppper most on the 44 as its laying down.

1 comes from the bottom of the tank on the genny and has the facet pump on it. its the lowest port on the bung.

2. in the middle of the bungreturns from the drum to the tank breather hose

3. (highest) has the breather from the 44 drum.

while the genny gets its routine run up and test load the facet pump transfers fuel to the 44. the 44 cant overfill because ofport #2 returning to tank. when the test run and load banking is done the genny is refueled from the tanker truck and anyone with small gennys or appliances can come and get essentially unacounted fuel from the drum on top of the genny.

usually FPDS has at least 50% redundancy so the drum will get swapped across from one to the next as required.

and before anyone gets onto the fruad bandwangon

the diesel that used to come out of the tanks... used to get sent back at commonwealth expense for disposal.

Originally Posted by bacicat

Yep, I size gensets as part of my current job.

A 60KVA would work, but it is the smallest unit that would do the job and would grunt getting the second motor away. The 88KVA is a much better choice - your Electrician was right to do that. Sales guys don't know as much as they think sometimes.... I am one now.... But I'm also a qualified Sparky who's been working only on gensets - both on and off the tools - for the last 18 years.

Oh, do you know what type of excitation the machine will have? There are 2 types - shunt and PMG. PMG excitation will give much better motor starting characteristics than a standard shunt excited unit. It will cost you another grand or so to go that way though. Also, some soft starters have issues with frequency changes like you see on a genset when a load is applied. It would pay to check the minimum and maximum frequency the starters will work at. VSD's work better off smaller genset supplies such as this.

PMG........

Good point about frequencies, I will run it buy the contractor that is building the switchboard.

Currently have prices on a

Himoinsa and Olympian.......need to make contact with the the company that the an offshoot of caterpillar, cannot think of there name, the info is in my diary. My research tells me to buy a quality jap build engine/unit

If you can deliver to brisbane and interested in pricing one up shoot us an PM.

Cheers