NL Genset AutoStart using Xantrex AGS

[twistedtree]

The issue with starting and stopping under load, as I understand it, is overload on the voltage regulator. During the spin up and spin down, the regulator is trying desperately to maintain voltage even though it's impossible to do so. Enough of this stress can ultimately cause failure of the regulator. It will be very dependent on load, and the exact regulator design.


The DynaGen AGS referenced earlier has an output signal indicating it's OK to apply load. That can control a contactor of sufficient capacity for your generator. When you press the Start button on the controller, it starts the gen, runs for a programmed warm up time, then signals that load can be applied. When you press the Stop button on the controller, it sheds the loads, runs for a programmed cool down time, then shuts down the gen.

 

[Arthurc]

Hi TwistedTree, I read through the TG350 documentation and it has 4 switched outputs that I think can be set to send battery voltage when the Genset is at idle (warmed up and stable), was this the output you were referring to? Looks like this might be the answer to both autostart and just protecting the Genset in general.

 

[ksanders]

I have worked with the dynagen units, and think they are pretty good, but...

I have also worked with the Deep Sea Electronics PLC product line of controllers for many years.

If I were going to put a generator control and protection system on it would be a Deep Sea unit simply because of the diversity of their product line.

I have kinda avoided putting a controller on my generator on the boat though. I have a controller on the exact same NL model at the shop, the land based version so I know what it entails. One of my thoughts is based around the fact that the controller becomes a single point of failure for the generator as it replaces the factory (very simple) relay based shutdown system.

On the subject of unloaded start and stop... I still do not see it as a real issue, but if someone wanted to switch the output of the generator on and off based on generator status that would be easy to do.

You would use a lighting contactor sized to the generator output (preferably a mechanically held one) and tie the open/close functions back into the generator controller. Easy peasy.

 

[BandB]

I pulled up a couple of NL manuals out of curiosity. While it may not be intentional and it's worth discussing with NL, on the smaller generators they say to let it run 3 to 5 minutes unloaded at start up and when stopping it. On the larger generators they say nothing about running unloaded when stopping, only when starting.

 

[ksanders]

I pulled up a couple of NL manuals out of curiosity. While it may not be intentional and it's worth discussing with NL, on the smaller generators they say to let it run 3 to 5 minutes unloaded at start up and when stopping it. On the larger generators they say nothing about running unloaded when stopping, only when starting.

Yes, they all seem to have that kind of verbage in the manual.

Yet...

Under NFPA 110 guidelines a emergency generator is required to be able to go from zero to loaded at full capacity, in one step, in under 10 seconds. Oh...and that includes outage detection time.

 

[BandB]

Under NFPA 110 guidelines a emergency generator is required to be able to go from zero to loaded at full capacity, in one step, in under 10 seconds. Oh...and that includes outage detection time.

I didn't know the exact guidelines but knew that on land we always want as near seamless as possible. No easing into it.