skipro3 wrote:
I've measured current draw on my 2012 Lance 855S jacks. All 4 running the camper up will draw 32 amps at the battery. I checked each jack and the highest current draw was 8 amps. I replaced my fuses with 10 amp fuses. I want to KNOW when the current demand increases so I can fix why.
If you are blowing a 30 amp fuse on a single jack, you got a BIG problem. I can guarantee that the wires at my jack are NOT rated for 30 amps. (with the length of wire, 30amps should be a 10 gauge wire at 12vdc) You were lucky the fuse went and not the wiring burn up.
The current draw can easily exceed 30 amps, momentarily, when a jack reaches the end. A brushed electric motor is essentially a dead short when at stall. Only the resistance of the armature coil limits the current. Be sure to pack several extra 10 amp fuses, you will likely need them!
The wires are not going to burn up in the length of time that it takes a fuse to blow or a circuit breaker to open. That's WHY they are fused.
skipro3 wrote:
Think about it; if these jacks are fused at 30 amps each, multiply that by 4 and you would potentially draw 120 amps just to run the jacks before a fuse would blow. WOW!!
The factor installs 30 amp fuses and I hope I have explained why. Yes, 120 amps would be the total draw if all four motors were stalled. Not likely to occur and only for as long as it takes the fuses to blow or for the operator to take his/her finger off the button.
Old-Biscuit wrote:
Mark the jacks 1" from hitting full travel/upper & lower limits. Stop jacks when 1" mark reached and then you won't be blowing fuses/cbs from overload.
Good idea and I plan to. Waiting for the cold and rain to stop here in the NW before attempting to mark the jack limits.
