Blowing Fuses/Possible fire hazard

[barry]

I have a 85 , 36' convertible. At the AC shorepower connection, the 30 amp fuse on the left will blow if both AC's are running but not with just one running. The amp meter on the boat panel is showing only 15 amps with both running . A little history is that the marina had electrical problems feeding my dock shore power ( complete break of wiring and had to pull new wire about 125 feet ). While this was happening they moved me to a different slip and shore power and everything worked fine until they moved me back to this slip . My question is : Is it safe to assume that the new wire they pulled inadequate as far as amperage load ? Or could it be that the previous problems have weakened the fuse holder that is holding the 30 amp fuse ? I am going to call the marina owner today and have him move the boat back to another good slip and try it. Thanks for any thoughts.

 

[SeaEric]

1. Inspect the cord ends very carefully for any evidence of burning or damage.
2. Inspect the power inlet on the boat likewise.
3. Unscrew the inlet from the boat and inspect the wiring connections and wire that goes to the AC panel.
4. Check the fuse holders carefully for corrosion and damage.
5. As available voltage decreases, amperage increases. Check to see what you have coming in.
6. DO NOT TRUST the old original analog meters on your panel. Get a good meter on it, or spend the big bucks (as I did) and have some Blue Seas digital meters installed. You need to know whats really going on.

Don't fool around with this. A boat fire will ruin your day(s).

 

[Pascal]

I am a big fan of bright easy to read electrical meters like the ones n Eric's picture. It will tell you what is going on and if you locate them in the right location you can keep an eye on them to see when something isn't right.

These fuses at the shore inlet at a common source of problems as they age. You should look into replacing them by circuit breakers. Marinco (or Hubble) makes a waterproof breaker with e same chrome cap as found on shore power inlets. You can easily install it next to your inlet and enjoy protection without risking a fire...

 

[dsharp]

An 85 model should have breakers. Anyway as stated first check the shore cord plug for heat damage. Don't start both acs at the same time . The startup draw on the compressor is about 2x the running load.

 

[Maynard Rupp]

Our "86 36 Hat has the same 2-30 amp systems. The AC was an option on these boats and that is why they are completely separate systems. We have seen our amp gage show 35 amps with both units running. You can't do that for long. Those fuses are usually the first to go, but we have popped the CB in the panel also. They should have used a single 50 amp for all power. Here are 2 tips that have helped a bunch. Squeeze electrical grease in each female plug hole until it is full. squeeze the fuse holder contacts to make them tight on the fuse ends. Buy inly 30 amp slow blow fuses. Don't use the front AC if you can help it. We just replaced our salon Cruiseair unit with a modern one piece unit. The new unit draws a lot less amps so we might be able to run both units now. This was a design flaw with these boats.

 

[SeaEric]

My 2 original 1966 Air Conditioners typically draw 26 to 27.5 amps when both are running. The problem comes at a marina where their power is compromised by heavy use, so available voltage drops - especially if you're at the end of the dock. When voltage drops, amperage goes UP. I have a 16,000btu in the salon and a 12,000btu split between the forward and aft staterooms. At some point when replacement time comes I will most likely wind up with 3 self contained units to retrofit and get the compressors out of the ER. At that time it is likely that I will re-wire the inlet to a single 50 amp 240 and split it to the 2 panels.

 

[lumina]

Hi All,

Completely replaced both port and starboard shore power units (2011 or 12). Here are a couple of pictures just after the electrician finished, before I made permanent labels, cleaned and painted the inside of the cabinets and replaced the box covers (which act as shelving).

WELL worth the $$$ for the peace of mind........

 

[Boatsb]

Hi All,

Completely replaced both port and starboard shore power units (2011 or 12). Here are a couple of pictures just after the electrician finished, before I made permanent labels, cleaned and painted the inside of the cabinets and replaced the box covers (which act as shelving).

WELL worth the $$$ for the peace of mind........

Gene where is the safety lockout?