XW+6048 dropping AC2 qualification and using Generator support
Hi Guys –
First time caller here, just found your website and I’m glad to add another web-forum to my off-grid resource knowledge base
I have been on other solar web-sites and also stumbled across the writing of ChrisOlson previously. His thinking tended to steer me towards my system sizing when I first built my system 2 years ago.
Anyway, here’s my problem: when under fairly heavy load on my generator (Bulk charging at over 50% of generator capacity), my XW will disqualify the AC2 input when larger loads switch in and out. I think I can solve this with some adjustments on my XW but I wanted to ensure I didn’t damage anything before tweaking.
First off, here’s my system components:
- 48V FLA battery bank with 428 A/H capacity at C/20 (Rolls S-550 batteries)
- Conext MPPT 60 150 charge controller
- 12 260 solar panels
- Onan 5KW CCK propane generator (old school but in good shape. I like it as it’s a classic workhorse). That decision and technical support has been from Smokstak.com (another great site).
So I assume that part of my problem is the response time of the generator when reacting to changes in the load. There’s a brief duration where the Onan needs to adjust to the demands of the load and when that happens, the XW disqualifies AC2. I see there are settings for qualification of voltage and freq. If the load is fairly constant, everything works pretty well.
Here’s what I would like to do:
- During Bulk charge (max load), I would like to load the generator at 4KW (don’t want to push it too hard).
- According to my calculations for charging rates, my bank should be charged at minimum of 42 Amps (10% of C/20 rate) = 2KW plus loads (which are generally low)
- Use Generator support feature to reduce the battery charge rate for short durations like water pump being switched on.
- Not have AC2 disqualified when loads switch in/out as it interrupts the Bulk charge process.
- I read that there are qualification
settings for voltage and freq of AC2. I haven’t changed anything settings
for fear of damaging the XW due to poor quality AC. Question: if I start
to adjust the volt and freq limits (say +/- 5% or so), do I need to
worry about damaging the electronics in the XW with out of spec AC or just the other loads
(TV, fridge, water pump ect)?
- Should I first focus on adjusting
Volt or Freq or both?
- I had tried to get the Gen Support feature working (enabling and adjusting the ‘GenSupport’ Amps) but it never seemed to do anything. I didn’t adjust the AC2 breaker setting so perhaps that was part of the problem? Anyway it’s time to try again as that was early days when I first installed the system. I assume that the calculations are done at 240VAC and not 120VAC? For example, if I want to limit the load on the genset to 4KW then the GenSupport Amps setting should be: 4000/240=16 Amps (perhaps my problem was that I used 120VAC as the voltage for this calculation).
I realize that I may have to do some work with the governor on my Onan genset but before getting into that, I thought I would loosen up the qualification settings on the XW.
I look forward to learning more from this site as I find this all very interesting for my off-grid mainly seasonal cabin.