Circuit Breaker rating help needed.

[Friscoboater]

I am restoring a 1986 Carlson CVX-18 and I am looking to replace the breakers in it. They are ETA 1658 but the little pole that has the rating is sun damaged and I cannot tell what they are. Does anyone know what a good idea of rating to use.? I was thinking a 50 for the ignition and 10 amps for all the switches.

 

[Don S]

Re: Circuit Breaker rating help needed.

I was thinking a 50 for the ignition

Mercruiser used a 50A breaker on the engine, and a 20A fuse off the I terminal (Purple wire) of the ignition switch.

Switch fuses depends on wire size. 16ga wire would use a 10A fuse, 14ga. wire would use 15A max. You can go smaller to protect a a particular unit, but not larger.

 

[jimbo_jwc]

Re: Circuit Breaker rating help needed.

Is the red resetable overload themal the ignition on my 3.0 mercruiser 50 amp and wired direct to battery and controlled from key to contactor ? If so 50 amp feed breaker and ign control coil/choke maybe fuel pump ,lights ,blower , 120 watts lights , music ,bilge pump . I would go to atleast 60amp if standard price and hope you never had to turn them all on at once . Ship to shore radio . WW Grainger has nice lighted boat rocker switches that are marine .

 

[Bill3434]

Re: Circuit Breaker rating help needed.

If you know all the electrical components are "properly working" you could just hook up an amp meter to the circuits and turn them on to see how much current they draw. If the most current say is 7 amps then a 10 amp fuse would be appropriate. The one for the ignition would really depend on how it is wired; relay switch or solonoid. You may find that it doesn't draw a lot of amps.

 

[jimbo_jwc]

Re: Circuit Breaker rating help needed.

Is choke heater always on with ign coil ? 20 amps sounds plenty and I drilled hole and pilot light so I know when I leave ign on as I still have points .

 

[Don S]

Re: Circuit Breaker rating help needed.

DO NOT try to pull power off your ignition switch battery terminal. Keep the engine an ignition on the engine harness, and run another fused positive and negative leads to a fuse panel at the helm.
You don't want an engine electrical problem taking out the rest of the boats electrical system, or vice-versa.

 

[Friscoboater]

Re: Circuit Breaker rating help needed.

Thanks Don. I will stick with that formula.