solar mppt disconnect

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yycwrangler

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Apr 27, 2024
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Hello everyone..Jumping into solar for the first time. Have a renogy package (I know eyes are rolling). 4X100 panels/40amp rover mppt. I want to put a disconnect between the PV and mppt. Info from back of panels states
4 Pcs 100 Watt 12 Volt
Monocrystalline Solar Panel
Maximum Power: 100W (each solar panel)
Maximum System Voltage: 600V DC (UL)
Open-Circuit Voltage (Voc): 22.3V
Short-Circuit Current (Isc): 5.86A
Optimum Operating Voltage (Vmp):18.6V
Optimum Operating Current (Imp):5.38A
I will be using them in series and I want to purchase a dual pole dc circuit breaker but not sure amps and volts of breaker. Would it be a 10amp/15 amp? Any help would be greatly appreciated
 
I use these between my panels and charge controllers. I insert them inline and they are easy to use,

Quick way to disconnect controller from panels. I use then on the output also.

Remember to turn on the battery to controller connection first and disconnect last when connecting. The battery supplies control voltage to the controller.

If wired in parallel 40 or 50 amps if series the amps can be less.


 

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In a series connection, the voltages add while the current stays the same as a single panel. Parallel connected panels are the opposite.

Your 4 panels in series will produce up to 89.2 Volts DC. You need a switch or circuit breaker DC rated at sufficient voltage to handle this. DC rated switches and breakers are constructed differently than AC only versions because when the contacts open DC's continuous voltage sustains an arc much more readily than AC where the voltage drops to zero 120 times a second.

Current protection on RV size solar arrays is largely irrelevant. The panels will never produce more than their rated Short Circuit Current (Isc) which is only 10% more than their maximum operating current. In this case 5.38 amps under normal conditions vs 5.86 amps into a short. Operating into a short doesn't hurt the panels and any breaker that will handle the normal currents won't trip if the panels are shorted.
 
I use these between my panels and charge controllers. I insert them inline and they are easy to use,

Quick way to disconnect controller from panels. I use then on the output also.

Remember to turn on the battery to controller connection first and disconnect last when connecting. The battery supplies control voltage to the controller.

If wired in parallel 40 or 50 amps if series the amps can be less.


Thanks Huey, I just ordered 3 , I especially liked the small size and ease of installation.
 
In a series connection, the voltages add while the current stays the same as a single panel. Parallel connected panels are the opposite.

Your 4 panels in series will produce up to 89.2 Volts DC. You need a switch or circuit breaker DC rated at sufficient voltage to handle this. DC rated switches and breakers are constructed differently than AC only versions because when the contacts open DC's continuous voltage sustains an arc much more readily than AC where the voltage drops to zero 120 times a second.
suggest 100 V DC capability

Current protection on RV size solar arrays is largely irrelevant.
depends on the wattage and configuration.

The panels will never produce more than their rated Short Circuit Current (Isc) which is only 10% more than their maximum operating current. In this case 5.38 amps under normal conditions vs 5.86 amps into a short. Operating into a short doesn't hurt the panels and any breaker that will handle the normal currents won't trip if the panels are shorted.
multiple parallel/series strings require fuses..
all depends on the wattage..

ill expand here with this statement:

IF the ( parallel ) array short circuit amps are greater than the panel maximum series rating then you need to fuse the array at the point where the strings are combined.
 
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