Circuit Breaker Sizing For Solar System

From there you d land your inverter s output into a 50a breaker and your done.

Circuit breaker sizing for solar system. There is a code rule nec 690 64 b 2 that s says you must not exceed a certain size circuit breaker for solar. This works well in a system that is comprised of more than one string inverter or several branch circuits of micro inverters. Remember the fuse and breaker are there to protect your cabling from overheating and potentially catching fire. By stephen cliftontechnical representativewhen hooking up your renogy system the best way to add protection is by using fuses or circuit breakers.

So use a 20a circuit breaker. Use this table to decide what size battery to inverter cables and overcurrent devices fuses breakers to use with your inverter. The main purpose of the fuses and breakers are to protect the wiring. Circuit breaker sizing of suitable circuit breakers for inverters under pv specific conditions content the selection of the correct circuit breaker depends on various factors.

When downsizing a main breaker is not an option for the site you should consider amp shaving. As circuit breakers cbs and overcurrent protection devices ocpd are designed for 100 rated current i e. This adds a bit more labor and costs into the mix but it will help get that pv system stuffed into that service panel. When sizing this combined fuse breaker we must first determine the worst case current that will flow based on our specific panels.

3 follow the code. Recommended inverter cable and breaker or fuse sizes. They are not necessary for the system to run. Especially in case of pv plants some factors have a stronger impact than in customary electrical installations.

Fuses and circuit breakers are used to protect the wiring from getting too hot and also protect all devices connected in the system from catching fire or getting damaged if a short circuit occurs. A 30a circuit breaker can safely carry the exact 30a current but nec suggests 80 as a safe current limit as compared to the rated current. The size of the wire and circuit breaker must be determined in accordance with local codes and regulations and in consideration of the environmental conditions the equipment will experience. So you always want to be sure your sizing your wire to handle the output of each circuit in the system.

So for example if you have a 200a service you cannot install more than 40a of solar circuit breakers 200 0 2. This is defined as 20 of the overall home s service rating.