I just replaced the 35 amp OEM alternator with a 100 amp Delco.

Everything is working as planned except that the 100 amp circuit breaker
between the engine battery and the house bank trips after about 10 min
if I set the charge rate any higher than 70 amps.

My house battery bank is about 800AH deep cyle and over the past 3
weeks, since I haven't been on dock power or had much wind for the wind
generator, I'm down to about 50%. I really need to get a full charge so
I can proceed with a much needed equalization charge.

I don't think I should increase the breaker size since it is sized to
the cable between the battery selector switch and the two battery systems.

I thought this might have something to do with the current flowing in
the opposite direction to the normal load, however, I reverse the
breaker leads and but the problem remains. I have several other Blue
Seas 7002 100 amp breakers in the system and I'm considering an exchange
to determine if I have a faulty breaker.

Any comments or suggestions would be appreciated..

Steve
s/v Good Intentions

"Steve" wrote in message
...
I just replaced the 35 amp OEM alternator with a 100 amp Delco.

Everything is working as planned except that the 100 amp circuit breaker
between the engine battery and the house bank trips after about 10 min
if I set the charge rate any higher than 70 amps.

Generally a breaker should be sized about 25% higher than the max
expected load. The accuracy of breakers isn't all that good.

My house battery bank is about 800AH deep cyle and over the past 3
weeks, since I haven't been on dock power or had much wind for the wind
generator, I'm down to about 50%. I really need to get a full charge so
I can proceed with a much needed equalization charge.

Doubtful that an equalization charge is needed after just 3 weeks.

I don't think I should increase the breaker size since it is sized to
the cable between the battery selector switch and the two battery systems.

I don't think you have a choice. The wire size is based upon the system
as originally designed. When tripling the size of the alternator you must
expect that some of the other components of the system will have to be
upgraded as well. What is the size of the wire and the distances of the
runs?

I thought this might have something to do with the current flowing in
the opposite direction to the normal load, however, I reverse the
breaker leads and but the problem remains.

Why would current be flowing opposite just because the alternator
is larger? Breakers don't have polarity.

I have several other Blue
Seas 7002 100 amp breakers in the system and I'm considering an exchange
to determine if I have a faulty breaker.

Could be. Have you measured the actual current through the breaker in
question?

Any comments or suggestions would be appreciated..

Steve
s/v Good Intentions

The cables between the engine and house bank was sized for the 100 amp
alternator I just installed. ( I just got around to installing it) I'm
not on the boat right now so don't remember what that was.. I know the
breaker was sized to the cable size running between the two.

The reason I mention needing an equalization charge.. I neglected to do
this before leaving the dock this spring, not realizing that the
batteries have lost some capacity over the last year.

I have taken actual current readings of the actual alternator output
(via a shunt at the alternator). No doubt about the output and it is all
going directly into the house battery bank. However, due to the risk
of the breaker opening and leaving an open output on the alternator, I'm
now leaving the engine/house battery selector set to "BOTH" for
protection sake.

I only considered the "reverse current" because some have argued this is
a matter of consideration in breakers (LOAD/SOURCE terminals). It was a
simple matter to test this possibility.

Thanks again Doug

Steve
s/v Good Intentions

Steve, FWIW check with Blue Seas, there was a recall on some of there
breakers awhile back.

"Steve" wrote in message
...

The cables between the engine and house bank was sized for the 100 amp
alternator I just installed. ( I just got around to installing it) I'm
not on the boat right now so don't remember what that was.. I know the
breaker was sized to the cable size running between the two.

The reason I mention needing an equalization charge.. I neglected to do
this before leaving the dock this spring, not realizing that the
batteries have lost some capacity over the last year.

I have taken actual current readings of the actual alternator output
(via a shunt at the alternator). No doubt about the output and it is all
going directly into the house battery bank. However, due to the risk
of the breaker opening and leaving an open output on the alternator, I'm
now leaving the engine/house battery selector set to "BOTH" for
protection sake.

I only considered the "reverse current" because some have argued this is
a matter of consideration in breakers (LOAD/SOURCE terminals). It was a
simple matter to test this possibility.

Thanks again Doug

Steve
s/v Good Intentions

Andy K. wrote:
Steve, FWIW check with Blue Seas, there was a recall on some of there
breakers awhile back.

"Steve" wrote in message
...

The cables between the engine and house bank was sized for the 100 amp
alternator I just installed. ( I just got around to installing it) I'm
not on the boat right now so don't remember what that was.. I know the
breaker was sized to the cable size running between the two.

The reason I mention needing an equalization charge.. I neglected to do
this before leaving the dock this spring, not realizing that the
batteries have lost some capacity over the last year.

I have taken actual current readings of the actual alternator output
(via a shunt at the alternator). No doubt about the output and it is all
going directly into the house battery bank. However, due to the risk
of the breaker opening and leaving an open output on the alternator, I'm
now leaving the engine/house battery selector set to "BOTH" for
protection sake.

I only considered the "reverse current" because some have argued this is
a matter of consideration in breakers (LOAD/SOURCE terminals). It was a
simple matter to test this possibility.

Thanks again Doug

Steve
s/v Good Intentions



I'll do that, but I recall that the 7002 breakers weren't included in
that recall.

Thanks,

Steve
s/v Good Intentions

That's true and the recall had nothing to do with the trip point.

"Steve" wrote in message
...
Andy K. wrote:
Steve, FWIW check with Blue Seas, there was a recall on some of there
breakers awhile back.

"Steve" wrote in message
...

The cables between the engine and house bank was sized for the 100 amp
alternator I just installed. ( I just got around to installing it) I'm
not on the boat right now so don't remember what that was.. I know the
breaker was sized to the cable size running between the two.

The reason I mention needing an equalization charge.. I neglected to do
this before leaving the dock this spring, not realizing that the
batteries have lost some capacity over the last year.

I have taken actual current readings of the actual alternator output
(via a shunt at the alternator). No doubt about the output and it is all
going directly into the house battery bank. However, due to the risk
of the breaker opening and leaving an open output on the alternator, I'm
now leaving the engine/house battery selector set to "BOTH" for
protection sake.

I only considered the "reverse current" because some have argued this is
a matter of consideration in breakers (LOAD/SOURCE terminals). It was a
simple matter to test this possibility.

Thanks again Doug

Steve
s/v Good Intentions



I'll do that, but I recall that the 7002 breakers weren't included in
that recall.

Thanks,

Steve
s/v Good Intentions