Generator Charging Issues

Dcline

Good Morning,

New to this technolgy so please bear with me if I don't know all the lingo.

I am working with an off grid system.
(2) XW5548 Inverters
XW SCP
XW AGS
Com Box
Conext Battery Monitor
Kohler 14RESA Generator
Batteries (830 AH)

My problem is the following:
Generator starts as required by the trigger setting, the inverter is reading about 1.5KW (lights and various loads) with the AC2 LED lamp flashing and then switches from reading KW to Amps on the front panel and rises to around 99Amps and shuts down and resets and starts this over again.

The other issue I have is that I can hear the generator change speeds when the above happens and after a couple of times the generator with go off on a faulure of Low Frequency.

Please let me know your thoughts.

Thanks Dan

BB.

No expert here... But it sounds like your AC2 input maximum branch circuit current rating is not set correctly?

14,000 Watt genset rating / 240 VAC = 58.3 amps max continuous rating

Some of the equipment will, if you program 60 amps "branch circuit" rating will only draw 80% of that:

60 Amps max rating * 0.80 = 48 amps functional draw

Which is what I would suggest you start at for a maximum draw for your genset.

Your genset will surge to 20,000 Watts (I think, just a quick looks at the specs):

20,000 Watts / 240 VAC = 83.3 Amps max

So, drawing 99 amps (@ 240 VAC on AC2 input?) does not seem right.

-Bill

MichaelK

Have you changed the charging rate?  For my 6848, the default rate is 140A, which at ~50V would be 7000W.  I only have a 6000W generator.  By reducing the charging rate I can get the generator qualified by the 6848.  Funny thing is that my generator can output power up to about 36% (~50amps), but it can NOT be started at 36%.  It will do exactly the same thing you are describing.  I start it out at a very low 10% (14amps), let it run till completely warmed up, then incrementally up the percentage a point at a time till I get to about 36%.

With a 830Ah battery, I'll assume you want to charge at about 83A?  That would be a 60% setting if you have the same 140A default?  At 50V that's >4200W.  That's a fairly hefty load even for a large generator like your Kohler.  That could get problematic if you want it to work with an AGS.

mcgivor

Do you have a means of adjusting the settings, system control panel  (SCP), ComBox, configuration tool or Gateway? The frequency acceptance  setpoints may be too narrow, or both inverters are changing at maximum capacity, they do ramp up so initially it may begin to charge but overloaded the generator when full output is reached.

If the generator is audibly struggling that would be an indication of overloading, which in turn would reduce the frequency, did you or someone else commission the system.?

Dave Angelini

Do you own this system? New owner?

You need to know what frequency the genset is at when it connects. Do you have a means to read gen frequency? You can read this on the combox meters screen for AC2.

The other issue with these older inverter/chargers is the stacking for multi inverter. Cables are good? Works fine without the genset?

This needs to be solved ASAP because you can damage the input relays, or one of the two or both have been damaged. 

I would get one of the units (the master) working correctly, reduce charge current and test. Then add the second. As MichaelK suggests you only need 80amps or a bit more to charge. Two chargers is too much for your bank anyway.