Classic 150 & Genset Autostart

[Boompy]

Hi all

I'm currently running a Classic 150 on a remote telemetry site (100% off-grid). Its been purring along beautifully for about 9 months. Great product... loving the remote data logging capabilities!

In the interests of enhancing the system's redundancy I will be adding an auto-start generator to the power system.

This will be used for low solar insolation periods - which are pretty rare in the land Oz but the Engineer in me wants to enhance the resilience of this installation to ensure uptime and protect the AGM's from deep discharge in the event of freakish weather conditions.

In order to perform generator auto-start I am considering using the Classic 150 AUX 1 terminal to control the generator (2-Wire Auto-start will be implemented).

Is this a feasible solution? Can I trust the classic with this task?

I am using a Whizbng Jr and associated shunt, so I can trigger based on battery voltage or SOC. I assume battery voltage would be the more reliable trigger parameter??

I would basically be using the genset to perform an early morning bulk charge and then let the panels do their bit for the rest of the day.

My system will utilise a Xantrex 30A 24V charger - there is NO inverter in this system. I am only utilising 24V DC loads.

I could look at using an alternate load / input monitoring system in conjunction with a PLC to control all of this, but I can't help but think that the Classic and its inherent monitoring capabilities is more than up to the task. Am I on the right page here? I'd love to hear your feedback.

I could use the Xantrex charger with an optional battery temperature monitoring sensor also, but I assume this is overkill. Am I correct in assuming that using the battery voltage (from the Classic) to start and stop the genset is all that is necessary and safe (from the batteries perspective) to control the genset charging operations??

I'd really appreciate your feedback / advice.

Thanks!!

[SolarMusher]

Classic auto start is reliable, you'll be better to use SOC to start and stop this gen. I've done it on Kohler two wires but my customer didn't like that it stopped the gen without delay so I changed it for a system networked AGS which allowed better controls. If I recal it correctly the Classic Aux SOC didn't allow to charge more than 90% SOC (why???) but it will be perfect if you only want to bulk these batteries. With a stand alone charger, start and stop without delay could be an issue on the gen when it's cold.
You will also need a 12V relay or cheap SSR to switch signal.
IMO as it is, this AGS would really need to be improved with more functions.
Be safe,
Erik

[boB]

If I recal it correctly the Classic Aux SOC didn't allow to charge more than 90% SOC (why???)

Erik, this would be news to me, but I am old and not without brain farts so please let me know if this is really the case.

I seem to remember making it so that it would go to either 100%  or maybe only 99%  ?  It was real close
to 100% though, if not 100%.  (I think)

boB

[toothy]

I used a delay timer from 3rdbrakeflasher.com to give me some warm up time, its totally adjustable. Didn't do anything for the cool down though but my load is fairly light at that point. The timer is simple, works and is cheap.

Wade

[Boompy]

Classic auto start is reliable, you'll be better to use SOC to start and stop this gen. I've done it on Kohler two wires but my customer didn't like that it stopped the gen without delay so I changed it for a system networked AGS which allowed better controls. If I recal it correctly the Classic Aux SOC didn't allow to charge more than 90% SOC (why???) but it will be perfect if you only want to bulk these batteries. With a stand alone charger, start and stop without delay could be an issue on the gen when it's cold.
You will also need a 12V relay or cheap SSR to switch signal.
IMO as it is, this AGS would really need to be improved with more functions.
Be safe,
Erik

Thanks Eric and others for the posts.

Sounds like I'm on the right track using the Classic AUX in conjunction with a relay. I'm curious to know why a timer is important. Why is it a problem to simply stop the genset at a desired SOC - I'm obviously missing something here.

When do you require a timer and why?

Eric you said you used a networked AGS, could you elaborate on this. I'd be interested to know what AGS systems people recommend. Given that I'm not using an inverter (just using a battery charger), there don't seem to be many options out there that don't utilise a high level / proprietary interface with a respective inverter model.

Thanks

[SolarMusher]

If I recal it correctly the Classic Aux SOC didn't allow to charge more than 90% SOC (why???)

Erik, this would be news to me, but I am old and not without brain farts so please let me know if this is really the case.

I seem to remember making it so that it would go to either 100%  or maybe only 99%  ?  It was real close
to 100% though, if not 100%.  (I think)

boB

boB, not so young too and not sure if that was 90% or 95%, but what I'm sure is that the Classic didn't accept a 99% or 100% setting, so in that case where the gen was the only way to absorb batteries in this unattended system from december to march because of trees and snow on roof, I had no other choice to change it for a Magnum AGS networked to the system to get it to float every 10 days. I'm pretty sure that I had set it to the max and that it was 90% (not more).

Boompy, a networked AGS/inverter (magnum, xantrex, outback) allows you to add a delay before to pass through current to charger/loads and to stop the gen with a delay (1 or 2mn) only after all charge parameters (soc, end amps, time) have been met.
Here, in winter when temps are regularly -20/-25°c, it's important to have at least two minutes to preheat the gen before charging.
You can also set a quiet time period (night), exercise period (every three weeks), check run hours, etc...
I have never use an external timer with AGS and can't comment on this.
Erik

[mike90045]

Generator timer & Shutdown

When a generator is started, if the engine ambient temp is below, say 70F, it will stumble and surge or smoke when a hefty load (6Kw battery charger) is thrown on it.    It takes my diesel about 8 minutes to warm up to accept full load without smoking badly.

At shut down,  if the engine and alternator have been working hard, everything is heated up and being cooled by the fans. If you stop it quick, the engine can overheat from the sudden loss of cooling air, and windings on the alternator can also overheat if it too, was working hard.  Generally, a 2 or 3 minute no-load cool down is desired to prevent problems.
   But if the battery charge has been tapering off for the last half hour, things may be cool enough for a immediate shutdown.

[Boompy]

Hey guys

Thanks for your assistance.

Where I come from low temps are never an issue, so you've sure schooled me there Thanks for the explanation re startup and shutdown delays. I really appreciate the detailed responses.

Is there any real benefit in using an ancillary relay to perform the start / stop operation (assuming no start / stop delays are required) other than acting as a physical isolation point?

I'm only planning on using a set of dry contacts on the charge controller to open or close circuit the 2-wire connection to the generator.

Thanks again guys

[2twisty]

I use a GSCM-Mini to covert from 2-wire to 3-wire generator support. I have a Harbor Freight genset that I hacked to allow for remote start. I use a propane solenoid valve to flow propane into the intake for cold-start.  It's wired to the starter wire, so that anytime the starter is active, the propane is turned on.  Starts up beautifully.

My genset charging is done with my VFX3648, so I set a 30 second delay before transferring loads and charging when the inverter sees the generator power.  I also set the transition back to battery from genset to occur at 108VAC, so when the GSCM-Mini shuts down the generator, it cuts back over to batteries before damage can occur to the genset from shutdown under load.

There are more "clean" options out there, but I'm on a budget and I'm a tinkerer.  So, my steampunk genset works -- not pretty, but it passes the Wife Test -- I leave her here at the homestead for a week or more at a time and it all "just works."