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Generator Amp Draw - On Start

Yahoo Message Number: 16674
Any ideas on how many amps it takes to start one of the Onan generators? Working on sizing my power leads to it.

Re: Generator Amp Draw - On Start

Reply #1 –
Yahoo Message Number: 16675
image1.png

This chart is obviously a guideline, but considering your run from batts to the generator on the Kodak chassis is fairly short, I would be more than comfortable using 0 gauge leads...I think the quality of cable and the terminals is just as important as the gauge chosen. Remember, weakest link in the chain is the most restrictive. Let me know what you end up doing...I'm going to start a rewire project soon.

Chris
05 Seneca 35GS



Re: Generator Amp Draw - On Start

Reply #3 –
Yahoo Message Number: 16677
Looking good Kendrick! Unless I'm missing something that run of AC from shore to inverter should be pretty simple... Are you thinking much more than 40A 8 guage? Against a lot of advice here.. I'd be OK running that under chassis. The reason I say that is because the only time that line is hot is when you are stopped and on shore power. I'm with you on the 2/0 and 3/0 for DC... I'm pulling mine out of the barn Tuesday for a memorial day trip.. I'll see what the factory leads are to the Gen. Hope the project turns out great!

Chris




Re: Generator Amp Draw - On Start

Reply #4 –
Yahoo Message Number: 16678
Yeah that’s my thinking also, I can tuck it up tight along the frame rails. It’s only going to go 4ft, then right inside to a double gang box. All the electronics will be mounted on a HDPE backer board ½” thick.  Should make for solid mounting and not attract any moisture.  During winter storage ill pull the batteries out and keep them in the garage and seal the vents off.  I already plan on putting some foam in them to make sure I keep the box vented but also keep the dust out.  Good luck this weekend. I hope to be cutting and welding!  KG  From: SuperCrvgroup@yahoogroups.com [mailto:SuperCrvgroup@yahoogroups.com] Sent: Monday, May 21, 2018 12:38 AMTo: SuperCrvgroup@yahoogroups.comSubject: Re: [SuperCrvgroup] Generator Amp Draw - On Start    Looking good Kendrick! Unless I'm missing something that run of AC from shore to inverter should be pretty simple.... Are you thinking much more than 40A 8 guage? Against a lot of advice here.. I'd be OK running that under chassis. The reason I say that is because the only time that line is hot is when you are stopped and on shore power. I'm with you on the 2/0 and 3/0 for DC... I'm pulling mine out of the barn Tuesday for a memorial day trip.. I'll see what the factory leads are to the Gen. Hope the project turns out great!  
Chris   

Re: Generator Amp Draw - On Start

Reply #5 –
Yahoo Message Number: 16679
Hello Kendrick,
I really can't answer your question regarding the number of amps and I must presume you are talking about a diesel 5500 onan.
I can tell you that I can start mine with a small lawn mower battery. It has #2 gauge wire supplying battery power and #6 wires supplying/C
the AC current it produces.
Got a couple of notes to pass on to you.
The rubber hose on the gen oil dip stick tube is defective and known by onan to rupture and spray oil over the entire generator.
Onan has a replacement but they know that rubber hose is defective as well. No, not covered by any warranty. I fabricated and replacement ran the dip stick tube out the front of the case. I have read of owners having the item replaced then the replacement ruptures in weeks.

While the fuel filter can be accessed from the bottom removable plate, the fuel pump is under the radiator and cannot. As my pump was giving trouble, I removed both, bought an inline diesel filter and fuel pump and re ran the fuel line out the back of the gen box and attached

the filter and pump adjacent to the gen where I could easily access them.
Some Onan's have a 3 piece front cover that allows access to the inards. I cut the front cover in 3 pieces and installed additional bolts where  I could remove a section and get to the inards if necessary.
I'm sure you have notice there is no water temp gauge or oil pressure gauge. I installed a "T" in each of the lines and installed gauges. It seems more relaxing to know what is actually going on.

While I had it sitting on blocks running, I noticed the air flow was exiting several locations. I fabricated some thin metal that was used as a baffle to increase the air flow thru the radiator. This made it run cooler.
When the gen was installed at the factory, they set the gen then ran the cable, fuel supply and return and AC power lines to the generator with no slack. Therefore, when the gen was removed to perform work, each of these had to be disconnected. I added a few feet to each and now can remove the gen without disconnecting these items. Also make it easier to work on because I am not required to splice in each to run it sitting on blocks. Also covered the bottom of the muffler compartment and ran the exhaust outlet to the front bumper and reduced the noise.

I took a bunch of time and a lot of cussing to get the parts and such but it works great. Locally have 2 Onan workshops and they simply told me they didn't like to work on these little beasts and would dodge every attempt they could.
They provided me assistance in the form of schematics but told me I a customer brought in a unit that had been changed in any way from the factory assembly, such as relocating the fuel filter, pump, oil dip tube or such, they would be required to return that unit to factory condition before they could turn a single bolt.

Don't know if that is fact or not.
Good Luck

Re: Generator Amp Draw - On Start

Reply #6 –
Yahoo Message Number: 16680
My only concern is having the inverter in same compartment as batteries. The fumes from lead acid batteries will destroy just about any piece of electronics.
Nothing in Onan manual on starter amps. 150 to 200 amp should be about right. Use chart to size for that.

Best
Ron Hall

Re: Generator Amp Draw - On Start

Reply #7 –
Yahoo Message Number: 16681
image1.png

Here's how my Onan Generator and Shore power are coupled in my Seneca

Monte

Re: Generator Amp Draw - On Start

Reply #8 –
Yahoo Message Number: 16682
The generator box door is highly vented with 2 24x4" vents the small amount hydrogen produced should easily be vented just fine in this case with only 4 batteries. This was an initial thought of mine also, but after looking at the vents yesterday and looking at how my PPM it needed to be flammable I came to the conclusion to go for it.

KG

Re: Generator Amp Draw - On Start

Reply #9 –
Yahoo Message Number: 16683
Man you hit all this right on the head!

We did what I call a mini in-frame on the generator last weekend, and encountered everything you mentioned. One thing i found was the previous owner put a drain valve on the oil drain with a tube so that made the oil change less messy until we did the filter. We actually did the filter from the top with the front cover off, let me back up so I took the chance to do a full once over, and found the exhaust flex tube was cracked and replaced this along with all new gaskets. Fuel and air filters replaced too. When I ordered the parts I added a new drain fill tube because of what I have read here of them failing, but upon inspecting mine it was clear of any cracks and felt good for rubber. I kept the part on the shelf but for now it seems fine. We didn't change the fuel pump, but in the future depending on the use of it i do like your idea of moving all that stuff external for easier maintenance.

Has anyone added a second muffler to the generator? I picked up a generic flow through unit I plan on having a muffler shop install when we run the exhaust, if it lowers the sound down 2 or 3 DB for the 40$ I figure it will be worth it LOL.

KG