inverters

[thirteen]

Al (neighbor) sent me an e-mail and wanted to know what to put between his two inverters. One is a Victor 3000w and the other is a Volgen (he is not sure of the number)T1895. they both run off the same power supply. two banks= with four T 105s in each bank. His problem is that everything thing is ok until he uses both systems at once then he gets static in his computor and radio and it interupts his hydrophonic (sp) controls for his watering system. They are not tied together one supplies power to one side of his house but not the other side. Could there be interferance that is caused by both inverters being side by side? He added the Volgen early last year and has only had problems the last month with his garden controls. That is all the Volgen controls and four black lights and watering controils. I am not sure but I think one or the other inverter is going bad. Any ideas? Hope this is enough information?

[thirteen]

I forgot he charges his system with solar panels and has a 4000w generator as backup.

[Flux]

Could be a lot of factors. Don't know the inverters, the Victor sounds like a msw and they often cause noise and static on many things. Not sure what the other one is.

Added to the potential problem of the individual inverters causing static you are almost certain to have beats and intermodulation between them, there is no synchronisation between the voltage transforming inverters  or the frequency of the ac switching part.

It may help to add big electrolytic capacitors directly to the input terminals of both inverters and hope that the line feeding them acts part of a filter. Clamping ferrite cores round the feed cables between the battery and the electrolytic may help some more.

Grounding things effectively without causing loops may be a difficult thing but some form of grounding will likely be needed. RFI filters on the outputs of the inverters may help but they may already be incorporated. Don't try adding big capacitors to the ac output of msw inverters.

I think you have a tricky problem to solve and you will need a very logical approach to try to locate which is interfering with what.

Much of this is luck anyway, many people get perfectly good results with computers on msw but occasionally there can be problems. I suspect that there is a lot more trouble with the old crt monitors than the lcd ones.

I really have no idea about the garden equipment and how sensitive that is. You may also need to investigate any form of pwm charge controller that could be intermodulating with the inverters. Any common cables will have to be avoided, each inverter will need to have its own leads direct to the battery terminals.

Glad it's not my problem, I think you may struggle.

Flux

[thirteen]

Thanks From Al. He told me that he was using the same ground for everything and outside found a lead that had burnt on an outside light last month. The light worked with a new bulb but it had shorted to the flow sencer for his water meter which was on the other system. They were on the same bracket. He replaced wires and isolated the two items. Everything cleared up. They had shared negative leads from the batteries. He also grounded the inverters separately and told me his power usage was less.

I told him He owe's you a winter tomato or winter head of lettuce. Thanks thirteen