Amps Draw and Voltage Drop Question 2
Question 2 -17 Oct -------- There are no dumb questions--until now! If the furnace draws 8 amps and there is a 0.2v drop when it is on, and you change the positive wire to the furnace to a fatt...
Forum Discussion
MT BOB wrote:
OK,do you have an issue with your furnace? A little background-- yes the motor will slow down when voltage drops, all is normal.You are protected by the sail switch. Manufacturers build them to be in a RV, so they anticipate lower voltages.
They are rated to operate fine and safely down to 10.5 volts. That is why they have 10 volt motors in them.I have seen older Hydroflames run until voltage dropped below 10.0. If you suspect an issue, you must measure the voltage AT the furnace, not on the RV's panel,which reads the battery itself.
I think the OP is more concerned about when the furnace is running plus the inverter is heavily loaded the combined load is enough to send the inverter into low voltage alarm or shut down when the batteries have been discharged to 50%..
Op may have though reducing the voltage drop at the furnace would reduce the current drawn by furnace, in the case of DC motors, nope..
OP could try much bigger wires to the inverter, even reducing the voltage drop by .1V at the inverter terminals can make a big difference.. Reducing the voltage drop between inverter and batteries can have a pretty positive effect, as the DC input voltage goes up to the inverter, the lower the DC current will be required to maintain the 120V load.. Watts is Watts..
