Installing Solar Electric Since 1983



What's wrong with the GSLC?

The GSLC is a connection cabinet associated with the Outback Radian series inverter. We generally like the GSLC, but it does have some serious design defects. Below are explanations and photographs.

Click on thumbnails for full size photo.

The biggest problem is the lack of wiring space and the breakers with wiring access at the rear:

View of the GSLC as factory wired. On the left is the dead-front. Breakers on the top are AC,on the bottom are PV. This is how hard it is to work in one of these cabinets.
We take all of the AC Breakers out of the GSLC cabinet and put them in adjacent off-the-shelf load centers. If we leave PV breakers in the cabinet, we try to minimize the quantity. Here we have only one ganged breaker for charge control output. The charge control input breakers are in the combiners which are in the same room. The PV breakers are on the top spaces. The entire dead-front was wired while clamped in a bench vise. Note the AC wires are leading straight through.
Above is a Radian install with two outboard load centers. One is inverter fed and the other is generator fed. In the generator fed is an interlocked breaker fed from the generator to allow bypassing of the inverter system. Above is a shop-built interlock. In order to receive a feed from the generator, one must first de-energize the feed from the inverter(s).
Above is the router jig that we use to cut the slots in the interlock neatly and precisely. The notches are cut with a band saw.  

Below are some other problems with the GSLC and associated equipment.

Why is there no knock-out here? It is right below connection points? Here is the pre-wired GSLC as arrived from the factory. We unbolted the dead front and here is how it looked. We always order them as empty and wire them ourselves.
The standard Mate3 bracket is designed to mount on the left side of the cabinet. If you want to mount it on the right side or on a standard Jibuti, you have to modify the standard bracket or build your own. Above is a custom aluminum bracket we field built to allow the Mate3 to mount on a standard 4S box. Outback should provide hardware that interfaces with standard electrical equipment.
Our pre-wired GSLC had lots of problems, including loose screws. How is one supposed to access this bus bar? We remove most of these and make our own connections externally. Also, how could you expect your average electrician to add a circuit to one of these? We install standard AC load centers externally instead.
We recently received two GSLC cabinets that had missing and damaged parts. The negative shunt supports a heavy bus bar that is unsupported during shipment. The box was dropped and the moment of this unsupported shunt broke the base of the shunt. The A and B bus bars and screw packets were missing. Outback failed to respond and we had to track down the manufacturer ourselves in order to get the parts we needed to finish the job.  
Conclusion: We like the Radian inverter and the GSLC in general, but these problems need attention to improve the product. There is no easy way to provide breakers without back-mount studs. We just don't use them unless absolutely necessary. We hope the information above helps professional installers develop better methods.