Circuit Breaker Sizing For Solar System

Use this table to decide what size battery to inverter cables and overcurrent devices fuses breakers to use with your inverter.

Circuit breaker sizing for solar system.

Sma recommends having a licensed solar contractor or electrician determine the correct conductor and breaker size. Recommended inverter cable and breaker or fuse sizes. This adds a bit more labor and costs into the mix but it will help get that pv system stuffed into that service panel. Difference between circuit breaker and isolator disconnector circuit breaker size calculation for continuous non contentious load.

This works well in a system that is comprised of more than one string inverter or several branch circuits of micro inverters. So use a 20a circuit breaker. From there you d land your inverter s output into a 50a breaker and your done. Especially in case of pv plants some factors have a stronger impact than in customary electrical installations.

When downsizing a main breaker is not an option for the site you should consider amp shaving. By stephen cliftontechnical representativewhen hooking up your renogy system the best way to add protection is by using fuses or circuit breakers. There is a code rule nec 690 64 b 2 that s says you must not exceed a certain size circuit breaker for solar. When sizing this combined fuse breaker we must first determine the worst case current that will flow based on our specific panels.

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. Remember the fuse and breaker are there to protect your cabling from overheating and potentially catching fire. As circuit breakers cbs and overcurrent protection devices ocpd are designed for 100 rated current i e. 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.

3 follow the code. 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. They are not necessary for the system to run. So for example if you have a 200a service you cannot install more than 40a of solar circuit breakers 200 0 2.

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. This is defined as 20 of the overall home s service rating.