Shutdown Energy on Overflow

os.loadAPI("ocs/apis/sensor")
prox = sensor.wrap("right")

function print_r ( t )
    local print_r_cache={}
    local function sub_print_r(t,indent)
        if (print_r_cache[tostring(t)]) then
            print(indent.."*"..tostring(t))
        else
            print_r_cache[tostring(t)]=true
            if (type(t)=="table") then
                for pos,val in pairs(t) do
                    if (type(val)=="table") then
                        print(indent.."["..pos.."] => "..tostring(t).." {")
                        sub_print_r(val,indent..string.rep(" ",string.len(pos)+8))
                        print(indent..string.rep(" ",string.len(pos)+6).."}")
                    else
                        print(indent.."["..pos.."] => "..tostring(val))
                    end
                end
            else
                print(indent..tostring(t))
            end
        end
    end
    sub_print_r(t,"  ")
end

while (true) do
    details = prox.getTargetDetails("4,-1,0")
    if (details["StoredPercentage"] > 75) then
        print("Energyzufur wird abgeschaltet...")
        redstone.setOutput("left", true)
    elseif (details["StoredPercentage"] < 50) then
        print("Energyzufur wird eingeschaltet..." .. details["StoredPercentage"])
        redstone.setOutput("left", false)
    end
    os.sleep(5)
end