Electrical Question on a 1,2,3 switch

[Ron20324]

BARTENDER- #2s for everybody! The neg conductors have to be able to carry the same current as the pos. Sorry, but you should make them both the same. Note that the neg battery-to-shunt wire could be fed with 260 amps. Did Stu have you get a terminal/lug crimper when you started all this? It'll pay for itself. I use the hammer type.

I suppose the more recent practice of fusing the DP is learned from past troubles- a safety feature that is cheap insurance.

 

[Bob S]

Ron,

I bought the crimpers that Sailingdog recommended in Mainesail's post about making battery cables. I was also fortunate enough to tackle this project when Boater's World was going out of business. I was able to get some incredable pricing on wire. Just day's before they shut their doors I picked up a remnant spool of black #2 Anchor Marine for $84.00. It had just over 100' on it.

Bob

 

[Ron20324]

Ron, I was also fortunate enough to tackle this project when Boater's World was going out of business. I was able to get some incredable pricing on wire. Just day's before they shut their doors I picked up a remnant spool of black #2 Anchor Marine for $84.00. It had just over 100' on it. Bob

OOoo... a major killing at that price, Bob. I bought Acco 5/16 HT chain for a dollar a foot- probably one-fourth the best price elsewhere. They swore it was the 145 it was labeled. I got it home to mark it, and it was 176 feet.

 

[Bob S]

I drooled at at some of the prices that could be had. I only wished I had more money to spend. It was kind of sad though, I grew to like their sales people.

That chain was a great deal, now you have an all chain rode.

 

[Stu Jackson]

Fuse & EG wire

1. The fuse blew when I tried starting her, not before because the chart plotter was active. I did state I had the Radar, Chartplotter and Depth instruments running but I neglected to say the Fridge was also on. Ron, the run from the house bank to the switch is only 6-8'. I can and will replace the paralleled #4's with a #2. Today I increase the fuse size to 200 amps.

2. Question for the both of you. I used #4's on the ground side of this system. Is that a problem? Should I increase those to #2's also?

1. Aha, a big load in addition to just the starter. Sure go ahead.

2. Maybe. The immediate answer would be yes, but! I would calculate the voltage drop in the lengths of wiring you have. Although Ron might beg to differ you could parallel another #4 from your shunt to the EG. Or replace it with a #2. Which is $$.

 

[Ron20324]

you could parallel another #4 from your shunt to the EG. Or replace it with a #2. Which is $$.

Stu, as all too often we see, the big picture unfolds with every post, and like most threads, if we knew all the facts at the start, things would be alot easier. You overlooked were Bob said he has a big spool of #2 and a crimper. That means NO additional cash outlay except for maybe the heat shrink to cover the lugs. In that light, he could probably replace ALL the #4 with 2 and still have some extra.

As proven before, even a doubled-up #4 would still be fused at the lesser rate of 150. A #2, 200. In fact, in circular mills, two #4's are equal to a #1, #1 being able to be fused at 245. But a sensible owner wouldn't do that, either.

Bob, I wonder if you changed out the 150 to a 200 on the rerserve battery and duplicated what you had when the fuse blew previously, does the 200 fuse still blow?

 

[Bob S]

Bob, I wonder if you changed out the 150 to a 200 on the rerserve battery and duplicated what you had when the fuse blew previously, does the 200 fuse still blow?

Ron, I haven't gotten that far. I believe the reserve battery is no good. I'll buy a replacement this week.

My sailing habits since the upgrade are to leave the switch in position 1 and start the engine from the house. I know the last time I blew a fuse the fridge was on. I'm not sure about the first time but I would guess I did. Last season I didn't use the fridge because my house and start batteries were only 60ah each. i probably started my engine 30+ times this year without blowing the 150 amp fuse. Who knows, the bilge pump may have turned on at that very moment. One thing is for sure, seeing it's happened twice I need to increase the fuse size even if it means increasing the wire size.

 

[Bob S]

Anyone see a problem using a car starting battery as the reserve?

 

[Stu Jackson]

Reserve bank

nope, that's exactly what they're made for!

 

[kevinrichie]

bob are you using a xantrex digital echo charge?

or is it some kind of combiner. The manual I looked at says that it should shut off if the difference between batteries is over 10 volts. I don't think it should try to charge a battery that is not hooked up. On the other hand if you switched from 1 to 2 and there is a large startup capacitor in something that would keep the light on for at least a little while till it drained trying to power everything else.