solar charge controller and domestic inverter. incompatible?

pashmina

Hi guys, i'm new here so go easy.
I've hooked up a 500w/24v array to two series batteries via a 20A charge controller. I've also connected a 1400w 24v domestic inverter to the batteries (the domestic kind that normally charges the battery when the mains is on). The problem is, when the solar array is connected and the controller shows it's charging, after a minute or so the inverter gives a 'low voltage' alarm and shuts off, even though the batteries are fully charged (showing 28v). Disconnect the solar panels and it's fine.
Is it possible the controller pwm or something is messing up the inverter somehow? Are they incompatible?
I've noticed you can get special Solar Hybrid inverters for just this job. Do I really need to replace my standard inverter with one of these?

Windsun

Re: solar charge controller and domestic inverter. incompatible?

What controller is it, and is the inverter hooked directly to the batteries?

pashmina

Re: solar charge controller and domestic inverter. incompatible?

Update: It turns out that the UPS alarm is 'battery OVER voltage' and not 'low voltage'. The Phocos CX20 charge controller has a setting for 'sealed' batteries, which seems to reduce the max charge voltage and helps to stop the UPS tripping out. Also, I swapped the Videocon Dual Tech 1425 UPS for a Su-Kam 'Smiley' UPS, (hooked directly to the batteries, NOT the 'load' output from the controller), and that seems to have a higher over-voltage trip (more than 30.0v), which also helps.

Should I invest in a 'solar hybrid' inverter (pretty expensive), which would presumably manage the distribution of mains and solar charging sources more intelligently, or am I okay with a simple charge controller and a standard home UPS, both hooked to the battery terminals?

Windsun

Re: solar charge controller and domestic inverter. incompatible?

You should be OK with what you have - there are no inverters that also have built in solar charge control, so even if you got an inverter with charging built in you would still need a solar charge control.

niel

Re: solar charge controller and domestic inverter. incompatible?

it would seem that if the batteries are a sealed type that the charger in the inverter may be overcharging the batteries and setting off the alarm in the controller. you may need to change the charging parameters of the inverter's charger or stop using it as it would damage sealed batteries when overcharging them.