There are several gauge sizes that are used in landscape.
How to wire landscape lighting. But its still not difficult. If you start to get close to the transformers capacity you may notice a drop in brightness of your lights. Another good method is to solder connections using a soldering pot and insert the soldered connection into a DRB tube filled with grease making sure the wire jackets are submerged in grease.
Installation of hard-wired lighting fixtures is simple. One easy way to conceal certain types of outdoor lights such as well lights is by placing them in planters. What is Landscape Lighting Wire.
250-300 feet use 8 gauge. Not sure it is a requirement to have low voltage landscape lights to be connected to a GFCI but it can hurt. 1 7 watt light x 125 875 watts.
One of the most common methods of wiring has been the daisy chain. Upon installation they operate securely for many years. But it is just as simple as using a relay to provide the AC power to the landscape system.
Place each fixture 8-10 feet away from each other. Wire breakage may still happen. HttpLightingDoctorca - In this video I will explain everything you need to know about How to Wire Low Voltage Landscape Lighting.
So lets determine what your voltage drop will be. Wire the lighting system. You do not need to lay the cables in a straight line.

