Sterling Inverter Problem

[Dougal]

Tried emailing Sterling about this twice, but never got a response either time:-(

We have a 600watt (1200 peak) inverter. Not new by any means. It’s the older aluminium chassis version.

Always worked pretty well when there’s no charge going into the batteries, but if the alternator, battery charger or solar panel is putting out a charge, then the inverter will usually trip, sounding the alarm. I’m ‘assuming’ that it’s an over volt situation, but don’t really know for certain. The volt meter sometimes shows as much as 14.4 volts.

Anyone know if there’s a way to solve this? Any form of adjustment inside the inverter? What about maybe a resister fitted in the power supply line?

Any thoughts?

 

[Lon nan Gruagach]

if it has an over volt trip, its there for a good reason, as in stopping it blowing up. A resistor on the batt+ is a disaster, it wont on;y drop your 14.4V to 12.8, but also your battery only 12.8 to 10.2 and only under full load while it merrily pumps out over 100 Watts of heat.

for just over £63 you can get http://www.ebay.co.uk/itm/600W-Pure-Sine-Wave-DC-12V-to-AC-220V-Power-Inverter-/330702676672?_trksid=p2141725.m3641.l6368 that wont trip till 16V

 

[pvb]

The older Sterling inverters were said to be able to cope with 10-15v input, so the inverter may be faulty. However, if it works OK when there's no charge, it may just be over-sensitive. You could drop the supply voltage, not with a resistor, but with a diode. This would drop about 0.7v, but you'd have to use a diode which could cope with the peak current, and it would have to have a heat sink (ie like a splitter diode). However, small inverters are cheap enough, so it might be better just to replace it.

 

[Dougal]

I must've been absent when inverters got so cheap. Never crossed my mind to look at non branded items. that eBay one above is even pure sine wave. Incredible price! Thanks for the link

 

[William_H]

I wonder if it is not a question of wiring. ie if your inverter is fed from a point closer to the alternator or solar than the batteries any volt drop in wiring when charging would result in higher voltage than actual battery voltage. Try running temporary heavy wires from the battery terminals to the inverter. This will mean you get actual battery voltatge to the inverter. Conceivably also you might have a tired battery such that terminal voltages rise with charging quite quickly rather thna battery taking the charge. Most inverter problems come from low voltage getting to it under load so strange it should go out with high voltage. olewill

 

[Dougal]

I already have that. The cable run from batteries to inverter is only about 45cm, and the batteries are in great shape. I would guess a new one is the answer. Thanks though. I appreciate the input.

I wonder if it is not a question of wiring. ie if your inverter is fed from a point closer to the alternator or solar than the batteries any volt drop in wiring when charging would result in higher voltage than actual battery voltage. Try running temporary heavy wires from the battery terminals to the inverter. This will mean you get actual battery voltatge to the inverter. Conceivably also you might have a tired battery such that terminal voltages rise with charging quite quickly rather thna battery taking the charge. Most inverter problems come from low voltage getting to it under load so strange it should go out with high voltage. olewill