Alright here we go my first of probably 5 million questions!!
I have a simple 30 amp 120v system on board. Shorepower is fed into a 30 amp main breaker through a 10 gauge wire. There are two branch circuits, one feeding two outlets and one supplying a 10 amp battery charger
. Both circuits are wired with 12 gauge wire and protected by 15 amp breakers.
I just purchased the boat and moved it to a new slip. The surveyor
I used suggested I have the 120v system inspected by an electrician because one outlet was not grounded and there was a "melting electrical" smell. He also noted that the battery charger
was getting hot to the touch after approximately 90 min. of charging
. I have not been able to get the battery charger to charge the batteries since I have moved the boat to the new slip and connected to shorepower there.
So far, with the help of employees at a local boatyard and a couple good books
. I have found and corrected the following problems with the system:
1. 12 ga. wire was used to make the run from the shorepower inlet plug
3/4 of the way to the 120v main panel. The wire was then spliced to 10 ga. wire to finish the remainder of the run. I removed this and used a new section of 10 ga. wire to make the entire run.
2. The circuit with the outlets correctly begins with a gfci outlet which was properly grounded at the main panel, however the ground wire from the downstream outlet was covered with electrical
tape and not connected to anything. So since the wire from the downstream outlet was run to the gfci outlet which is just below the main panel, I just connected it directly to the ground bus bar in the main panel.
3. I am not sure that this was a problem but it looked strange to me and the local boatyard agreed. The incoming neutral wire was connected directly to the neutral bus bar in the main panel instead of to the "line in" side of the main breaker. There was a short wire run from the "line in" side of the neutral pole on the main breaker to the neutral bus bar in the panel. It seems to me that this arrangement would essentially bypass the neutral pole of the main breaker (it is a two pole breaker) since the incoming neutral line is wired directly to the neutral bus bar. I was under the impression that these panels
come prewired however given the other other mistakes
and poor craftsmanship exhibited in other parts
of the boat
I would not be surprised if this configuration is different from the way it came from the factory. Anyway, I may be wrong, but I connected the incoming neutral wire to the "line in" side of the neutral pole on the main breaker and ran the short wire from the load side of the neutral pole on the main breaker to the neutral bus bar. PLEASE LET ME KNOW IF THIS IS WRONG THIS IS ONE OF THE ONLY CORRECTIONS I AM NOT SURE OF!!
Ok, now that you have the background, on to my main question. Following all the above repairs
, I connected to shorepower turned on the main breaker only and got a reading between 115 and 120 volts on the "line in" side of the main breaker. I also get the same reading when testing the load side of the main breaker. However when I turn on the breaker for the battery charger the incoming voltage drops drastically (reading fluctuates between 25-80 volts). I turned off the battery charger and turned on the outlets only, the voltage dropped momentarily but then returned to around 110 but then began to fluctuate between 90 and 110 volts (there is nothing plugged in to either outlet). While I was working on this, it became dark and a dock
light on my shorepower pedestal
came on. While still testing with the outlets circuit on, the incoming voltage dropped significantly and fluctuated between 25-50 volts. Just to be clear I am getting these voltage drop readings on the line side of the main breaker as well as the load side.
It seems to me that the problem is isolated to the incoming plug
for shorepower on the boat, the shorepower cord, or the dock
side of the shorepower.
Sorry for the book, anyone care to take a stab?