150 Amp Sequoia Alternator install with Photoman Bracket (Part 3 of 3) (1 Viewer)

[Dave 2000]

Nice write up, would be way more useful if you consolidated into one thread though.

I might have just missed it, but did you run a new charge ("B") wire from the alt to battery? If not, that seems like a recipe for disaster. I replaced my B wire with a new 1/0 through a 200a breaker.

IMO you should reduce that breaker size, 1/0 can only carry about 130....ish amps depending on construction material, this means the cable would burn in a short before the breaker tripped, unless I missing something?

Regards

Dave

 

[Dave 2000]

Wire Size (AWG)	Copper Conductor Temp. Rating	Aluminum Conductor Temp. Rating
14*	20A	25A
12*	25A	30A	20A	25A
10*	35A	40A	30A	35A
8	50A	55A	40A	45A
6	65A	75A	50A	60A
4	85A	95A	65A	75A
2	115A	130A	90A	100A
1	130A	150A	100A	115A
1/0	150A	170A	120A	135A
2/0	175A	195A	135A	150A
3/0	200A	225A	155A	175A
4/0	230A	260A	180A	205A

Just come across this guide, I thought 135 was about right but that is maximum for Aluminium cable, so if you have copper cable then that is rated around 150 - 170, so sorry f I gave you a heart attack. Given you are not going over 150 amp you could have used AWG 1 but I too am for overkill so agree with your choice or even gone heavier. I see the circuit breaker being the issue, a 200 amp breaker may not actual trip much before 250 - 280 amps, as it is the cable you wish to protect then I would consider a 130 amp breaker, as breakers tend to 'hold' longer than fuses, and the fact that your unlikely to need the full output of the alternator for more than a few minutes that may be the way to go? Or perhaps swap the breaker for a fuse of around 140 amps, they tend to tolerate a higher amperage of around an additional 5 -10 %, again fitting in nicely with the short period of time you expect to see full alternator output. Or if you insist on a breaker then increase the cable size to 2/0 so plenty of flexibility in your choice of fuse or breaker.

Regards

Dave

 

[LandLocked93]

Nice write up Brandon.




In this post I discuss the sizing of the charging wire and did a crude fusible link test. Around 26 seconds the load gets up to around 150 amps and the fusible link does not start smoking until around 1:00 minute. I did not go to complete destruction because I wanted to save the fusible link, but it did make it to about 1:30. My intention was trying to put around 150 amps through the stock 80 fusible link to see what would happen.

Exactly. And that test represents a worst case scenario - a straight short to battery. Something like a front quarter collision where body panels puncture into the factory wiring somewhere behind the links . In fact the puncture would have to be precisely between the batt post and the first fuse box more or less. I'd be curious to see the current level on the B+ wire with a 150A alt, the truck idling, at speed, with all acc. on and again with them off.

And not to ramble endlessly, but to ramble endlessly...
An alternator only responds with current in the presence of demand for current. Put another way, alternators aren't constant-max-current devices. Unless the battery shorts internally, the average resistance within a battery will keep the current flow on that B+ wire within specs for nearly all applications, throughout its working voltage range.

If you wire all accessories off the battery post (as should be done, w/appropriate fusing/breaker'ing), the truck itself will demand no more current than it ever has before and that's all the fuse links protect - the factory wiring harness.

A winch for example doesn't draw its current from the trucks wiring (behind the links). It is (normally) wired directly to the battery posts. The links never 'see' (facilitate the conduction of) the current demanded by those accessories. And when you're using the winch, it is the battery providing the lions share of that current. Not the alternator. Tho the alternator is there and responding to the demand for current that it sees from the battery, but it's some exponent less than the direct current demand of the winch in operation. (assuming you're also consuming fuel to run the truck at the same time)

Plus consider the use cases.
How often are all the accessories running when the truck is? And is the truck idling or at speed?
How many devices are high-current short duration and used when the truck is running?
How many devices are low-current/long duration and used when the truck is running?

I'm just suggesting that simply upping an alternator output *capacity* doesn't demand that OEM wiring be changed also (see para #2) It probably does no harm to upgrade them IF the upgrade is performed correctly (good cable/great crimps/hard to do w/o proper equipment). It's just not a 1:1 mandate in many cases. Especially if you have a second battery and feed it straight from the B+ post on the alt. This allows the max current capacity (should it ever be demanded) to be split across two B+ wires, lowering the amount of current each wire sees to well within current specs.

As @Cruzerman touched on above - and what I've suggested too - with sufficient storage the 90A OEM jobbies are more than enough to provide the amounts of current to keep that storage topped off by and large. Then let the storage provide all the current you need for the accessories.

@Photoman - I have recently come into possession of your bracket and a 130A alternator (came with something else I bought). And while the alt came with a 4-wire connector containing a 3-wire pigtail, I did not get the 3-wire conversion bit.
Do you sell them separately? Yes I could splice, but I'd like to preserve the factory 90A'er connector. That is what your conversion piece does, yeah? (the connectors of the 130A and 90A alts look very similar admittedly. perhaps no conversion needed? Haven't looked too closely yet)
My vintage 90A with fresh brushes is giving me no issues charging 500Ahr+ storage and I do not expect to see much of a diff in performance after the upgrade. Just doing it to have the extra capacity should it ever be needed.
LOVE the bracket and having the option to upgrade. Big shoutout to @Photoman for providing it to the Cruiser world!

Anyhoo, just thought some quantification was in order after reading some posts indicating some confusion about the whole thing.

Happy Trails!

 

[Photoman]

Exactly. And that test represents a worst case scenario - a straight short to battery. Something like a front quarter collision where body panels puncture into the factory wiring somewhere behind the links . In fact the puncture would have to be precisely between the batt post and the first fuse box more or less. I'd be curious to see the current level on the B+ wire with a 150A alt, the truck idling, at speed, with all acc. on and again with them off. ...............

I did some tests like that. Here is one. For what it is worth here is a load test I did at various rpms. The pictures are missing from 7 years ago, but the figures are still there. Note using a Warn 10000 winch raised the output up to 158 amps which would be going through the fusible link if left stock.

I can just sell the wiring adapter. PM me.

Edit to add > I put the pictures back in the one post above.

 

[Dave 2000]

So, back to the 150 -170 amp cable (assuming copper) and the 200 amp breaker, is the breaker gong to be reduced in capacity?


Regards

Dave

 

[haulin auss]

So, back to the 150 -170 amp cable (assuming copper) and the 200 amp breaker, is the breaker gong to be reduced in capacity?


Regards

Dave

Pretty sure Ancor 1/0 is rated above 200a in an engine bay, but I’ll need to double check that.

EDIT -

IMO you should reduce that breaker size, 1/0 can only carry about 130....ish amps depending on construction material, this means the cable would burn in a short before the breaker tripped, unless I missing something?

Regards

Dave

I'm not opposed to increasing the cable size, but per Ancor:

 

[Dave 2000]

Pretty sure Ancor 1/0 is rated above 200a in an engine bay, but I’ll need to double check that.

EDIT -



I'm not opposed to increasing the cable size, but per Ancor:
View attachment 2607000

Interesting that the table I found above has different ratings, I am not familiar with ratings outside of Europe but the tables are way different. In general a cable inside an engine bay has to be de-rated due to heat.

Regards

Dave

 

[haulin auss]

Interesting that the table I found above has different ratings, I am not familiar with ratings outside of Europe but the tables are way different. In general a cable inside an engine bay has to be de-rated due to heat.

Regards

Dave

I always go off of the manufacturer that is producing the cable I'm using, not all cables are built to the same standard.