Victron 75/15 charge controller load output

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Brutalvette

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I just got a victron 75 15 charge controller today. I hooked it up to 2 100w panels. The battery is charging, but I can't get the load output to work. I am trying to hook up a 1000w grid tie inverter. When hooked up to the load out put nothing happens. If I hook directly up to the battery the inverter starts working fine. Can someone tell me why? Is the inverter too big for the output of the charge controller?
Thank you
 
Have you tried hooking up a smaller load, like a 100W light, fan, blower motor, etc to verify the Load side was working?

It's possible the inverter is pulling more from the controller than it likes and is shutting it down immediately.
 
I haven't tried to hook up another load yet. I'm not sure what type of load I can hook up to the charge controller. I assumed it had to be 24v DC the same as my battery.
 
The charge controller will tell you what the output voltage is rated at. And yeah, it usually is. A 24V load could be anything that requires 24V, but just not so many amps.

You could also put a resistive load on it. Take a hair dryer or toaster and hook into it. Not sure if the hair dryer will run on 24V DC as it's designed for 110(240)V AC, but it might; but you're mainly needing the coils to heat up a little bit. The toaster should at least turn on.
Or you could use 2 DC motors connected in series. If you have a 24V (or there abouts, not the 18V) cordless tool, you could use that as a load, too.

What controller do you have? link would be nice
What inverter are you hooking up to it? again, link would be nice
 
The load output of a charge controller will usually be at battery voltage because there is no DC-DC conversion and it's just a direct connection to the battery. It usually can be switched on and off manually, do you measure a voltage across it when it's turned on with no load? Voltage should be identical, or very close, to the battery voltage.

Generally it's considered best practice to connect an inverter, or any other large load, directly to the batteries instead. The load output is usually designed for lower power devices and/or devices that need to be turned on and off automatically, like lights, depending on the time or the state of the solar input. It's also there to make sure you don't accidentally overdischarge the batteries which you could do with lightbulbs, for example. An inverter couldn't do this as it will turn itself off when the input voltage it too low.
 
The inrush current could be opening the circuit. Why not just measure the voltage at the terminals to see if you even have voltage?

I would try a smaller load... 24v LED light strips, light bar or led log lights often times all support up to a 24v input.

Alternately, make sure the load output is ON in software...
 
I will check for voltage at the terminals after work today. I did turn the output on at the controller. It has several different settings and I tried them all. My plan was to use this controller with a grid tie inverter, but I don't know what size it will run. I don't want to buy another inverter and not be able to use it.
 
https://www.victronenergy.com/uploa...ller-MPPT-75-10,-75-15,-100-15,-100-20-EN.pdf

15 amp max output... that's about 360 watts so keep that in mind.

Personally I would use the load output to control a relay, and then connect the load directly to the battery though a relay.

If the Victron is operating correctly then you probably have inrush currents that tripping it when you first connect it. It happens all the time with one of my BMS boards with my iCharger. It should easily be able to support the idle load when not charging, but it doesnt turn on.
 
CrimpDaddy said:
https://www.victronenergy.com/uploa...ller-MPPT-75-10,-75-15,-100-15,-100-20-EN.pdf

15 amp max output... that's about 360 watts so keep that in mind.

Personally I would use the load output to control a relay, and then connect the load directly to the battery though a relay.

If the Victron is operating correctly then you probably have inrush currents that tripping it when you first connect it. It happens all the time with one of my BMS boards with my iCharger. It should easily be able to support the idle load when not charging, but it doesnt turn on.
Click to expand...

Thanks for everyone's input. I appreciate the help. I was calculating the current draw incorrectly. I figured 1000w inverter 120v should be 8 amps. I didn't think about the DC side of it.
 
Calculate with 50A at least for a 1000W inverter running at 24V. I'd leave a bit more headroom and use 60A for the calculations. The inrush current will be much higher but only for a split second if the DC-side capacitors are discharged. If that is an issue, now or in your future setup, you could pre-charge the caps from another source before connecting it back into the circuit to switch it on. It's not very practical though if you have to do it regularly.
 
Its not practical at all if inrush is the root cause as soon as the LVD trips you are back in the same boat.

I routinely use the load port to control a relay instead of feed the load directly it will be your best course of action running an inverter of this size while maintaining the usefulness of the load port / low voltage disconnect.

The only downside really is that you cant accurately monitor consumption though the software application because that port is metered which was a pretty cool feature too.
 
Yeah, as I said, it's not practical if you have to do it regularly, either if you're running into the LVD all the time or just turn it on and off as part of the regular scheme of operation, for whatever reason.

I'd use a contactor in this case, not a relay. Especially not a cheap relay made from chinesium. A good quality contactor will prevent welding and arcing which is exactly what you want for longevity. A contactor is similar to a relay but it's the heavy duty industrial version.
 
I finally got around to installing a relay on the load side of the charge controller. I have a contactor on the way. It seems to be working now, however, after reading and using it there is a 2 minute delay. It doesn't seem like a will be able to use it anyway. Or I will have to raise my cutoff voltage to compensate for the extra 2 minutes.
 
Brutalvette said:
I just got a victron 75 15 charge controller today. I hooked it up to 2 100w panels. The battery is charging, but I can't get the load output to work. I am trying to hook up a 1000w grid tie inverter. When hooked up to the load out put nothing happens. If I hook directly up to the battery the inverter starts working fine. Can someone tell me why? Is the inverter too big for the output of the charge controller?
Thank you
Click to expand...
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