DIY Manual

44 | P a g e 10-543-1 REV A
DIY Manual
Circuit Breaker Voltage Ratings
MidNite circuit breakers are rated at 125V, 150V, 300V, and 600V. Our fuseholders are rated at
1000V and we offer two fuse options: 600V or 1000V (either can be used in the MN fuseholder).
NOTE: 600V fuses are available till current stock is depleted; thereafter, only the 1000V fuses will
be available.
Figure 12 shows a 300V circuit breaker, which are two 150V breakers connected in series via a
brass jumper. The other end of this 300V breaker will also have the -- and ++ terminals.
Remember, the ++ electrically points toward the highest current source, which is usually the PV
array for this type of breaker.
NOTE: Always check the torque on the brass jumper screws, do not assume they are tight.
Ground Fault Protection
“Ground fault” means a current carrying conductor (either positive or negative) is in contact with
earth ground. Referencing Figure 13, we see by the arrow a MidNite 63A GFP breaker. This is a
double stacked breaker with a normal 150V, 63A breaker on the left and a 0.5A shunt-trip breaker
on the right, wired at the top to the battery minus and at the bottom to earth ground. The shunt-
trip breaker detects voltage between negative and ground; if a voltage is present, the shunt-trip
will open causing the 63A breaker on the left to open, thus removing the positive PV connection
between the PV array and the charge controller.
Figure 12