Extension cord for shore power
I'll be plugging in at a house on the coast for a few days in a couple of weeks. My shore power won't reach and I'll need to come up with a cost-effective but safe way to plug in. I was thinking abo...
Forum Discussion
Drum wrote:
Do you see any problem with doubling them up for 50' or 75'? Can it be too long? It's got to go around the house to the other side to plug in.
Physically they will connect fine. Depending on the electrical load, it won't be "big" enough.
The limiting factor is voltage drop. If the voltage is too low at the trailer stuff will have trouble.
Voltage drop is caused by current flow (amps) through resistance (relates to wire gauge size). So for a particular cable - the more gear you have on and running, the more current flows and the larger the voltage drop. Or for the same gear running, the longer the cable the greater the voltage drop - even if it's all 30 amp 10 AWG cable.
The standard 10 AWG cable is rated for 30 amps. At full load (say the A/C is running, microwave is on, refrigerator is on, water heater is on) and cable that is 30 ft long (like mine), the voltage drop will be 1.8 volts. In my experience with my trailer, a 3 volt drop is fine but more than 5 volts is trouble.
Same load as above, but with a 25ft extension so it's a total of 55 ft, there will be a 3.3 volt drop. Maybe okay.
Add another to make a total of 80 ft and the drop is nearly 5 volts.
Remember, this is at full load. Turn off the heater and microwave and the load drops enough that the voltage drop isn't risky anymore.
So - if the reason for plugging in at home is so the battery can charge and the outlets work so you can run a vacuum cleaner, an adapter and a normal extension cord will be fine. But if you want to live in it, a 10 AWG - or maybe an 8 AWG - would be a really good idea.
