inverter problems

[africa green]

We had a short circuit in the wiring leading to the inverter from the main change over switch due to a faulty installation, resulting in damage to the inverter. After repairs it stopped working again.surely there should be something to protect the inverter from short circuits - either an external breaker or an internal fuse on the inverter? The company we are dealing with are being very unhelpful. Advice please !

[Logan5]

Brand names and Specs on components in this system? size of inverter? Battery bank size and voltage? what are the loads on this inverter? New install or updated older system?

[africa green]

Studer AJ 600 - 24 with 4 24v batteries. Installed 4 years ago and no problems. They just threw wires over the roof to the change over switch which we said was bad but they said it would be fine. Recently two wires crossed and short circuited the inverter, they said. It was repaired but within twelve hours it failed. They said this was caused by a short circuit in a light fitting. There were was no other load on the system at the time. Any thoughts?

[Logan5]

Who is they? an electrical contractor? are you saying they threw, DC or AC wires across the roof? loose? these are from the array to the controller? What is the current state of charge of your battery banks?

[africa green]

The company who sold and installed the system. The wires go over the roof from the controller to the switch that can change from solar to generator (we are off grid). The batteries are 26. something according to the controller. Afraid I can't be more technical - if I knew more I probably wouldn't be asking questions on this forum !!

[africa green]

Correction - the wires go from the inverter to and from the the change over switch not the controller.

[Logan5]

You did not clarify if this is AC or DC running across the roof. or what voltage.

[africa green]

The wires are AC. I said I am not technical so not able to answer voltage. I just would like to know what safe guards there should be to stop any kind of short circuit from damaging the inverter

[Logan5]

Well the wire running across the roof should be replaced with new wire in secured conduit. If not only for aesthetic purposes it should rerouted through the attic. It sounds like you had a poor quality install, I would first go over the system and re-torque all of your wire connections. battery terminals, solar panel connections, combiner box's as well as all connections on both AC and DC sides. a single loose wire can cause major problems. The wires strewn across your roof have been damaged and must be replaced. I doubt this wire is AC as you run a battery system, meaning DC is sent from the roof to the inverter in your home, where the batteries are.

[africa green]

Well I am glad you said that. We have already put the wires in conduit ourselves now even though the company insisted it wasn't necessary. We do not have an attic to reroute them through but it is not very visible so aesthetics are not a problem. Following the original malfunction due to a short circuit in these wires (AC or DC ??) we had another malfunction which the company said was due to a fault in a light fitting. I insisted they put an exterior breaker on the system to protect the inverter in the future but I am just astonished that there should be the need for this. Shouldn't the inverter have in in-built fuse or shouldn't any installation incorporate a mechanism to protect the inverter from such occurances ?

[africa green]

Can I ask if you are a professional in this area - you seem very knowledgeable? The reason I ask is in order to have some 'back up' when dealing with the company. As you probably realise, we are in Africa. When we were researching possible installers, this company seemed the most professional. However they treat me like I am an idiot and are hostile to explaining anything probably because I am a woman. While I don't claim to have any technical or scientific understanding, I do have a good amount of common sense and I like to know how things work. It seems as if this company is not as professional as they make out and think they can blame any fault on us.

[Logan5]

No, I am a Ham Radio guy experimenting with batteries and solar for decades. I have made mistakes on my own set ups. this place gives me the opportunity to share my knowledge and experiences, as well as learn from some smarties . I suggest doing a little reading, Basic electricity, Ohms law. If you are going to maintain this monster you are going to need to understand the basics. Read all of the off grid and battery stickies. Someone more knowledgeable will eventually step in.