Alternator question

This is exactly the reason I fume at BUZZWORD TERMINOLOGY.

Cootsey Wootsey Salespeak.

It would have been FAR AND AWAY less deceptive to simply write CIRCUIT BREAKER.

This is the era of buzzwords. Do not say PROBLEM. Say ISSUE, the same as an issue of stamps or coins. Oh the US Post Office is probleming a whole ----load of new stamps.

Or to Seinfeld a conversation by starting off with "So"

Is the first sentence or paragraph missing somehow? It must be. Or the sentence has started off with dull-knife butchering of syntax.

I write cursive explanations because it' easier on my fingers and folks who have zero interest in what I am explaining should proceed to a different thread. If they need details or explanations I will be glad to explain.

I use my own personal BUZZWORD. It is referred to as TOP CHARGING. It describes a unique charging protocol. I could have labelled it something like "Formula X Safety Charge". But to charge a battery "Top The Top" is sort of self-explanatory. Top Charge.

Grumble-Fume-Snarl-Snivel-Snap

westend wrote:

path1 wrote:
I have appointment tomorrow to get new tires, about 6 miles total driving. I don't want to re-schedule appointment as I need m/h next Monday.

But I'm waiting for elec part to come in. The part is what is called "shortstop" and I couldn't find any locally. Right now my pos and neg are disconnected at house battery and at the converter. All metal ends of battery cables taped up, so no contact with metal.

Question...When driving it, will the charge line under hood sense no power and do damage to alt? Or will charge line sense circuit is not complete not put out power?

In your other post about electrical problems, I suggested, along with others, you visit an auto parts store and buy an auto resetting circuit breaker.

I guess you are soliciting ideas here about your problems and then taking a "shotgun" approach to solving them. But, of course, you're free to do what you wish. The next time you have that "Shortstop" trip and can't find the problem or run your new batteries down to oblivion, you may think again about replacement choices.

Next month or in Sept, after back pocket recovers from buying tires, going to go with PD converter. Not sure which one, but will be PD as I've nothing but great about them on here. Doesn't look to hard, (on the surface). But its electrical(my bad spot) so going run by our RV guy first.

Remember, I needed this part fast and as far as which circuit breaker or substitute for it, (at the time), I couldn't tell you one from another. Tried NAPA and they only had type 1, non resettable. But I pick it up and used it to see if I found what my problem was with converter and making connection to batteries. (Why didn't I just volt meter? Because I didn't think of that at the time) But I wanted exactly what was OEM. I try to stay OEM.I've replaced to many waterpumps, starters,etc that say OEM and free replacement. But also found that doesn't count time or missing skin on knuckels on what was supposed to be OEM or better.

Thanks

"Gawd Maude, I Gots Me A Bullet Wound!"

"Nuthin that a little sassafras tea and mudpack can't cure"

The ONLIEST thing a SHORT STOP will do is eliminate transient voltage spikes in excess of 28-32 volts.

Wait! Make that TWO THINGS! Your wallet will lose weight.

But for the benefit of the Techie crowd here, I constructed links to eBay sites that actually have components to make a true 12-volt de-spiking system. It's parsecs ahead of a single stupid MR2535. The greater the spike amplitude the shorter the exposure time frame. The OVERLAPPING voltage protection of the three devices makes this system work. The response time of the TVS (middle item) is less than a nanosecond. For work in the 18-28 volt region, the MOV has lots of slow response capacity and a voltage spike that consumes a few thousand amps above 28vdc is something I got to see in person. Therefore the MR2535 has it's place.

But none of this stuff will be the slightest help in curing electrical problems not directly related to electronic component degradation due to transient voltage spikes. IE: A visit to the podiatrist would do little to cure vision problems.

Nothing is sadder than seeing someone ignore qualified advice and getting taken for a ride. To each his own.

PS For transient protection at the converter, add a 470uf 63 volt electrolytic capacitor to maximize protection.

Thanks every body. I didn't want to mess up anything. Tha's why I asked.

MEX...You are only 40,000 feet or more above my elec knowledge. I think these things are a rip off also. But my reasons are different than yours.

Anything elec I try to go with OEM. I figure you guys know more than me when you design an elec system. When I had a hard time getting a replacement locally a little light went off in my mind. I did a little digging around. Could find "shortstop" part number on mine, but nobody could cross reference my number. The spec's, yes. Part number, no.

Here is what I found out. Shortstop made by "Bussmann" originally, then bought out by Copper Ind, and changed part numbers http://www.cooperindustries.com/content/public/en/bussmann.html

Then that was bought up again and changed part numbers again. Now a division of Eaton. http://www.eaton.com/Eaton/index.htm

Talking with wife about part number confusion and she remembered a contact name at big elec dist that she used to business with. Called contact. They remembered my wifes name because they worked out how long the pay off would be if wife (building manger) upgraded to LED "exits signs" from indandescent. That's 17 floors in hosp including parking garages. By the way, pay off time was 3 1/2 years. So that's adds up into some big bucks. Remember, I'm only after a $10.00 part but I need it quick. They would "retail" sale to me if they had it on their shelf. Wives contact also had part number confusion. Contact said to come to sales office where located. When I got there in dirty jeans and tee shirt she already had her boss involved on part number confusion. I walked in with part, she went thru her files some more and we went into the "big boys" office. Big boss tried to get part confusion solved, then he called Cooper Ind and wanted to why, if the public can't find the right part number and TYPE and he can't, as an elec wholesaler, why do we even need your business. So over a $10.00 part for a retail customer, sales person spend maybe 20 min of their day on me. Big boss spent 15 min with me. In the end could not get locally.
Big boss ended up sending me link to Amazon with right Amps and "type". Type as in 1,2 or 3.

If anybody waded through this posting and if you have one of these "shortstops"...order a spare now or find proper replacement before you find yourself in same spot as me. Mine is original, supposedly made in last quarter of year 2000.

Here is link, and yes I know pic is wrong as it won't come with red plastic cover.

https://www.amazon.com/dp/B001BW8DSM/ref=pd_lpo_sbs_dp_ss_1?pf_rd_p=1944687582&pf_rd_s=lpo-top-stripe-1&pf_rd_t=201&pf_rd_i=B00DNIBGA4&pf_rd_m=ATVPDKIKX0DER&pf_rd_r=WN2Q8VD7BZA8BN7WFB1C

path1 wrote:
I have appointment tomorrow to get new tires, about 6 miles total driving. I don't want to re-schedule appointment as I need m/h next Monday.

But I'm waiting for elec part to come in. The part is what is called "shortstop" and I couldn't find any locally. Right now my pos and neg are disconnected at house battery and at the converter. All metal ends of battery cables taped up, so no contact with metal.

Question...When driving it, will the charge line under hood sense no power and do damage to alt? Or will charge line sense circuit is not complete not put out power?

In your other post about electrical problems, I suggested, along with others, you visit an auto parts store and buy an auto resetting circuit breaker.

I guess you are soliciting ideas here about your problems and then taking a "shotgun" approach to solving them. But, of course, you're free to do what you wish. The next time you have that "Shortstop" trip and can't find the problem or run your new batteries down to oblivion, you may think again about replacement choices.

Mexi
Is saying use the part number I gave you to replace that special order part you are waiting for
Or use the cheap diodes at the indicated connecting points
Removing spikes save other electronics in the vehicle
The use of the avalanche diode is valid, the special order price is ridiculous

Short Stop

Is

A

Ripoff

Buzzword for a Motorola type MR2535 avalanche diode, with a threshold of 28-32 volts. This gimmick caused a mini-sensation in the cruising sailboat world several years ago. At first the hucksters claimed that the "Short Stop" would minimize the effects of alternator "Load Dump" where the switch to the batteries was accidentally turned off while the alternator was charging hard. A dozen lawsuits later, the 3-card-monte business eliminated the claim from their ads.

Last month I purchased 100 MR2535 axial rectifiers from China or .22 each. That's twenty-two cents USA

But their intended use is to AUGMENT another (smaller) diode looking device called a "TVS" Transient Voltage Suppressor. The 200 TVS devices I purchased are rated for 16.0 volts DC. As a stop-gap buffering between the TVS voltage of 16.0 volts and the MR2535 voltage of 28-32 volts I chose to use a 20 mm Metal Oxide Varistor (MOV) rated 17 volts operational.

The alternator output stud is NOT the optimum place to mount a Transient Voltage Suppressor network (notice I wrote "network"). The converter output is a more rational choice to place a suppressor.

Your ENGINE air conditioner compressor clutch needs a suppression diode and it's easy to install. Not a special diode, a six amp or 10-amp regular silicon axial diode works fine. Determine WHICH of the two connections at the magnetic clutch is the + positive. The body of the diode has a distinct BAND at one end. For this purpose, orient the diode so the band faces (closest) to the + positive clutch terminal. Of course the opposite side of the diode gets connected to the - negative chassis ground, either at the remaining terminal or extended with a wire and hooked anywhere to a good - chassis ground negative.

This gets better...

Do exactly the same diode connection at the chassis engine starter motor. Same thing - the band of the diode is closest to the terminal. Do this for the small starter solenoid terminal, then do another diode for the starter motor positive power terminal.

Use heat shrink tubing to encapsulate the diode. It almost never sees an appreciable amount of current.

TECH STUFF: A collapsing field generates both POSITIVE and NEGATIVE transient voltage spikes. A wild-ass nine on the Richter Scale zig-zag voltage spike. By CLAMPING the Air Conditioner magnetic clutch, the engine starter motor, it's solenoid, the generator engine starter solenoid and it's starter motor, then placing a genuine transient voltage spike suppressor at the fuse/converter positive and negative busses, a genuine de-spiking network is created and both negative and positive transients get chopped off at the knees.

Such devices are a consumer hard-sell. This is why the makers of the MR2535 avalanche diode charge such a stupendous price for a diode, two wires, two terminals and swatch of heat shrink tubing.

The concept of "Just Pour Miracle Battery Additive XV-6 into the cells, and step on the starter!" is far from dead.

BTW the concept of AVALANCHE RECTIFIERS is valid. General Motors has been using them for decades as have been Mitsubishi, ND, and Hitachi. All six or eight power rectifiers in their alternators. They too are rated 28-32 volts.

You can do better than that. I just hope the swelling of seven or eight knuckles here has not been in vain.

As long as the chassis battery is connected all is fine.

path1 wrote:
I have appointment tomorrow to get new tires, about 6 miles total driving. I don't want to re-schedule appointment as I need m/h next Monday.

But I'm waiting for elec part to come in. The part is what is called "shortstop" and I couldn't find any locally. Right now my pos and neg are disconnected at house battery and at the converter. All metal ends of battery cables taped up, so no contact with metal.

Question...When driving it, will the charge line under hood sense no power and do damage to alt? Or will charge line sense circuit is not complete not put out power?

Your alternator is (or at least should be) connected to the chassis battery, not the house battery directly. It will work just fine, exactly as though it were an ordinary truck without the motorhome stuff attached at all. No troubles with driving across the country, much less a few miles.

A tiny caveat: Sometimes weird wiring things are done to RVs, particularly by (prior) owners who thought they had some idea what they were doing but in actuality may not have. Still, having the alternator sensing voltage at the missing house battery would be very very much unexpected and would tend to be problematic in other ways even if the battery were installed and connected.