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Topic: Generator Auto Start (Read 675 times) previous topic - next topic

Generator Auto Start

I recently (end of June 2021) purchased a 1999 U320. My wife and I just completed our second, short 4 day /three night trip. During our stay we had no shoreline power, just the 10K Powertech generator. I had the switch on the generator switched to the "ON" position and the dash rocker switch in "Auto Start" position.
Even though our electrical use on "house battery" was extremely low, the generator never auto started. When I went to manually start the generator the cranking speed was too slow and would not start. After three attempts the generator fault light came on on the dash, so I went out to the generator and toggled the on/off switch  to reset the fault lamp.
I had to start the coach engine, to start the generator.

I am looking for more detailed information on the generator "Auto Start" system to make sure I am not missing a simple step somewhere along the way.

Re: Generator Auto Start

Reply #1 –
I hope this helps
Peter and Frieda Morin
1999 36ft. U320 Foretravel
Build # 5436
1998 Suzuki Sidekick Sport

Re: Generator Auto Start

Reply #2 –
At your left when sitting in driver seat. One of the rocker switches is "boost" by selecting this to
"On", you now add the start battery to the house batteries. This should give you power to start generator in a low power time. BUT! it is smart to start main engine. Then select boost.
Why? Because if your batteries are weak, you may have a no start on engine. By starting engine then boost and starting generator. You now have the ability to charge start and house batteries.  Win!.
When charging you should have boost on. This to allow both house and start to charge. BUT!
Never leave boost on when not charging. By leaving it on. You can drain batteries.

So.
1. Check the health of all batteries.
2. Now check all fittings, connections. Not just visual. Remove, clean terminals, look at all connection condition. Fix.

Mark
1999 U270 40 #5518
USN. USPS.

Re: Generator Auto Start

Reply #3 –
"Oldguy" has provided you with the flow chart for the "Auto start". Add this to your paperwork. It will come in handy when you or anyone needs to troubleshoot this system.
Right now batteries appear to be the initial issue.
House batteries provide the power to generator for starting.
1999 U270 40 #5518
USN. USPS.

Re: Generator Auto Start

Reply #4 –
If you have the DynaGen BCM12 battery charge monitor, it may be set to wait to start the generator at too low of a voltage.  Here's the manual for that so you can check the start voltage setting.  Mine is set to auto start at 11.9VDC.  This might be a little early, but better safe than sorry.
Keith
2003 U320 38' #6197

Re: Generator Auto Start

Reply #5 –
I think mine is set at 12 volts but since getting at home I have never
used it.
Peter and Frieda Morin
1999 36ft. U320 Foretravel
Build # 5436
1998 Suzuki Sidekick Sport

Re: Generator Auto Start

Reply #6 –
Reasonable settings for turning on the generator depend to some degree on "after how long at this reading do I turn it on".

Said another way, if you use the inverter for high-demand appliances, you do not want the AGS to instantly come on at 12.2 VDC (50% discharged battery bank) as it will "rebound" when the heavy load is removed.
Brett Wolfe
EX: 1993 U240
Moderator, ForeForum 2001-
Moderator Diesel RV Club 2002-
Moderator, FMCA Forum 2009-2020
Chairman FMCA Technical Advisory Committee 2011-2020

Re: Generator Auto Start

Reply #7 –
How many house batteries do you have? 

Maybe I don't understand the autostart, but I prefer to control it manually.
Jason
2000 U295 36' Non-slide  ISC350

Re: Generator Auto Start

Reply #8 –
Quote from: Jason –
Maybe I don't understand the autostart, but I prefer to control it manually.
The battery voltage auto start system is designed to start the generator to charge the house batteries when they hit a certain voltage.  Mine is set for 11.9V.  Fully charged, they show 12.7V.  When not plugged in to power, the fridge and other draws pull the batteries down.  The auto start is designed to start the generator and charge the system while unattended, so you don't come back to a dead coach.
Keith
2003 U320 38' #6197

Re: Generator Auto Start

Reply #9 –
Quote from: WS6_Keith –
The battery voltage auto start system is designed to start the generator to charge the house batteries when they hit a certain voltage.  Mine is set for 11.9V.  Fully charged, they show 12.7V.  When not plugged in to power, the fridge and other draws pull the batteries down.  The auto start is designed to start the generator and charge the system while unattended, so you don't come back to a dead coach.

Thanks, that is great to know! Where do you set the threshold for it to auto start?
Jason
2000 U295 36' Non-slide  ISC350

Re: Generator Auto Start

Reply #10 –
Jason how many batteries do you have, was that meant for me I have
6 2 volt batteries 600 amp hours and I prefer to do it manual start also.  In the
winter when the temperature gets around 0 the engine won't start unless
I run it through the first start sequence and stop it a 9 seconds and then
restart it. If it is on auto start and tries to start it will go into over crank and
then I would have to go outside to reset it.
Peter and Frieda Morin
1999 36ft. U320 Foretravel
Build # 5436
1998 Suzuki Sidekick Sport

Re: Generator Auto Start

Reply #11 –
Quote from: Jason –
Thanks, that is great to know! Where do you set the threshold for it to auto start?
If you have the DynaGen BCM-12, I posted the manual in reply #4 that has the instructions how where to check and how to set it.
Keith
2003 U320 38' #6197

Re: Generator Auto Start

Reply #12 –
Quote from: oldguy –
Jason how many batteries do you have, was that meant for me I have
6 2 volt batteries 600 amp hours and I prefer to do it manual start also.  In the
winter when the temperature gets around 0 the engine won't start unless
I run it through the first start sequence and stop it a 9 seconds and then
restart it. If it is on auto start and tries to start it will go into over crank and
then I would have to go outside to reset it.


I was asking the OP. I've seen 2-4 batteries on coaches. I have 3 on mine. Haven't owned it through the winter, but when I'm at home I have it plugged in.

Keith - I'm unsure what I have, I'll have to find that out.
Jason
2000 U295 36' Non-slide  ISC350

Re: Generator Auto Start

Reply #13 –
Jason, I have three house batteries.
Since the coach is new to me, I am still learning all the systems. I used to be a vehicle and heavy equipment mechanic for a long time so I know my way around stuff. The schematic helps, although I would like a complete schematic of the coach electrical system from batteries on up.

Re: Generator Auto Start

Reply #15 –
Here is 2 more wiring drawing and I sent the air drawings by
mistake hope you can use it too.
Peter and Frieda Morin
1999 36ft. U320 Foretravel
Build # 5436
1998 Suzuki Sidekick Sport

Re: Generator Auto Start

Reply #16 –
Tboy66- I am new as well to these, just picked ours up 2 months ago, and am a shadetree mechanic. Can you add your coach in your handle so we can see what you have?
Jason
2000 U295 36' Non-slide  ISC350
 

Re: Generator Auto Start

Reply #17 –
We added the standalone Magnum autostart device. Found the autostart very helpful when we connected shore cable to campground pedestal and FORGET to turn breaker on. It does not take long for gen to autostart to notify we are not on shore power. We leave our inverter on 24/7.

Because we are not interested in bringing our house battery bank too low, we have the autostart set point at about 12.3 or 12.4.

Magnum highest start voltage set point was about 12.0, so we 'fooled' the Magnum by putting a small diode in series with battery volt sense wire, so battery voltage 12.4 looks like about 12.0 to Magnum.

We do not have Magnum inverter/charger.