Re: Shore power contactor burnt out

James Cromie

One thing that this contactor failure illustrates is that they do have a lifespan - whether it is a contactor used in standard domestic, marine, or other purposes.  Additionally, I have noted terminals can loosen over time - particularly with contactors where there can be repeated vibration / jarring.  This, in addition to possible corrosion, can cause terminals to loosen or have poor continuity, resulting in high resistance and ultimately melting components or causing fire.  

I know there are more experienced people on the forum than myself (electrical engineers, etc), but this illustrates the importance of checking electrical connections in the various circuits regularly (particularly those that carry high amperage), and ensuring that lugs are tightened and terminals are clean.    I know I’m preaching to the choir…  Perhaps I’m writing what I’m reminding myself of doing!

Soteria SM 347

On Jul 15, 2019, at 9:05 AM, Mark Erdos <mcerdos@...> wrote:

I put the switch in the engine room in the same location as the contactor.  This was the easiest location since it did not require splicing or replacing the main power cable. The switch required a larger junction box. I never start the genset without checking the oil so popping down to the engine room to change the switch is not a big deal. However, there have been a few times when I wish I had located the switch next to the remote start in the galley. If I had to do it over, I’d probably put it here.
With best regards,
Sailing Vessel - Cream Puff - SM2K - #275
Currently cruising - Vista Mar, Panama
From: [] On Behalf Of Eamonn Washington
Sent: Monday, July 15, 2019 8:31 AM
Subject: Re: [AmelYachtOwners] Shore power contactor burnt out
Thanks for the explanation Mark.

I rarely connect to shore power (650W solar panels), but I’ll try to replace it with an equivalent automatic switch.  But out of interest, if you install a manual switch, did you place it in an easier to access location (like near the generator switch in the galley)?  I might do that if it fails again.

Thanks again
Eamonn Washington
Travel Bug
Super Maramu #151
Currently in Trapani, Sicliy, Italy. 

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