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 > Your search for posts made by 'jharrell' found 14 matches.

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RE: Here we go again yet another Trombetta "Big Boy" failure!

Blue Sea, buy once cry once. Used them on boats in salt water, when I got my RV and had the cheap trombetta go out I replaced with: Its bistable with hysteresis so no chatter under any condition, silver plated contacts rated at 300 amp live switching, 500 continuous, 700 for 5 minutes and 1450 for 30 second cranking. It detects charging voltage on either side and engages in auto mode (so alternator charges house and shore charges starting) or the switch can be set manual on or manual off. Switch has a light letting you know its engaged. Direct replacement using same wires for combine switch that was already there (had to run extra wire for status light)
jharrell 02/29/20 09:37am Tech Issues
RE: shutting down generator with air conditioner running

They are powered by the inverter. But if you turn off the inverter the fans cease to run. Or, if 120 volt shore power is being used to charge the battery bank via the Magnum, is disconnected, the fans also stop running. The inverter is either running forward inverting making 120v or running in reverse charging using 120v. If it is doing neither than there is no need to actively cool the fets or transformer. The inverter has temp sensors on the fets and transformer, it will run the fans based on temp alone so long as it has at least 9.5v at the battery terminals: From the manual: The inverter contains two internal cooling fans that are automatically controlled. The speed of these fans is determined either by the internal temperature of the inverter or by the load on the inverter. The inverter’s fans will come on under the conditions listed below: • Fans run full speed if the internal transistors (FETS) or the power transformer reaches 176°F (80°C), or the inverter is running at 100% of its rated load. • Fans run medium speed if the internal transistors (FETS) or the power transformer reaches 140°F (60°C), or the inverter is running at 50% of its rated load. • Fans run low speed when the inverter is running at 25% of its rated load. The fans shut down if none of the above conditions are met, or if the battery voltage is < 9.5V. Whenever the inverter is first connected to the battery, the fans start for about one second.
jharrell 08/25/19 03:31pm Tech Issues
RE: shutting down generator with air conditioner running

The cooling fans on my inverter are AC motors. Turn off the inverter, and you turn off the cooling. That is why it caught on fire. Wait a sec. here........... Isn't the inverter supposed to produce AC power ? Why would the cooling fans NOT be powered by the inverter itself ? Am I missing something here ?? You are not missing anything, they are 12v dc fans lookup Magnum Inverter 44-0004 for the replacements, they do not run off 120v ac directly and do not require the inverter section to be on.
jharrell 08/25/19 12:25pm Tech Issues
RE: Voltage drop on inverter

One positive One negative Excellent practice This is why I despise unsoldered lugs Don't give a **** if they're squeezed till they fart, this would never happen with soldered lugs. Oh they look good Tighter than hell But it doesn't work There is ZERO protection between the interior of the lug surface and the stranded wires. I disagree and prefer crimping, these people explain why: In the marine world crimping is preferred due to oxidation and soldering can prevent flex at the lug joint as well leading to fatigue.
jharrell 08/10/19 05:08pm Tech Issues
RE: air conditioner without and with autoformer

Make sure Magnum shore setting amps correct, you should have noticed it, but Magnum could be trying to charge batteries and run a/c, lowering shore amps tells the charger to back off, also tells it when load support kicks in on hybrid. Autoform and generator really not a good combo, if gen can't provide voltage auto form pulls more current, dragging gen down even more. Gen should be throttling up to provide correct voltage and current up to its capacity otherwise something wrong with it.
jharrell 08/01/19 09:32am Tech Issues
RE: Microair vs Hyper Engineering?

Does an autoformer have the ability to start an AC unit when running on a 2000 watt generator? I am not sure how an autoformer would help, it increases voltage by increasing current on the input side, so your locked rotor current draw just went up on the generator. In the end power is the same, the voltage sag is due to the large amount of in-rush current to the motor. A soft starter like a Easy-star ramps up voltage slowly to motor limiting current in-rush. Would be interesting to know how a autoformer can help the situation, it actually seems like it would make things worse by drawing more current from the generator. BTW My Easystart works great on my Coleman 15k.
jharrell 06/17/19 05:11am Tech Issues
RE: Victron/lifeblue system 99% functional except

Make sure the temp monitor is on the right battery post, the only diagram I can find for the lynx shunt shows it on the positive post (from am solar): My Magnum temp monitor didn't like being on the positive post but thankfully did no damage, the manual showed it being on the negative. One thing I don't like about Victron is their documentation, Magnum has them beat here, can even find a manual to the Lynx shunt from Victron.
jharrell 05/30/19 04:36pm Tech Issues
RE: Deep Cycle Battery Charging From Alternator

And do not forget to add the effects of the starter solenoid itself. A large field collapse can definitely be felt. It is a magnetic servo as well as electric contact controller. This seems to be mostly what is found when talking about any kind of spike from starting due to anything powered off the starter switch during cranking and would be the same with a loaded or unloaded starting motor. Instead of a flyback diode on solenoid it seem a starter relay is used to drive solenoid and that relay may have built in diode, but its even smaller coil too. I would imagine in cars with remote/push button start there is transient protection on the solid state circuit controlling the starter relay. I don't know maybe modern starters have flyback diodes since they are so easy to add but no one seems to talk about it or care the main issue seems to be arcing and RF not giant spikes like you would see from a load dumped alternator. Definitely want to get a scope on my starter system and see how large the spike is at different point to see how well my batteries suppress it.
jharrell 05/08/19 06:02am Tech Issues
RE: Deep Cycle Battery Charging From Alternator

The gentleman that demonstrated max observed voltage as never reaching 30 volts. Well guess what, power avalanche rectifiers are rated 28-32 volts. And no way in hell is an automobile rotor coil as large an inductor as a five pound starter motor armature. Yes but a starter motor has something a alternator doesn't, a large solenoid that breaks the circuit. Also an alternator has something a starter doesn't, a large ICE driving it. How are you going to get a large spike from the starter motor through an open solenoid? Same with the solenoid coil as its cut by the ignition switch or starter relay. Again might get some arcing and small spike as the solenoid opens but otherwise how is it going to complete the circuit? Put your finger on the wire from solenoid to starter, yeah you complete the circuit whoopee. Disconnect the battery with the alternator going full blast and the entire cars electrical system is the load dump from the engine driven alternator output for half a second.
jharrell 05/07/19 02:27pm Tech Issues
RE: Deep Cycle Battery Charging From Alternator

If transient voltage events are rare and of little consequence why has General Motors, Nippondenso, and other manufacturers spent hundreds of millions of dollars converting all power rectifiers in their alternators from standard silicon to TVS snubber avalanche 28-32 volts? GM did it in the late 1980's. They also redesigned the 1116411 voltage regulator, then the 425 then the 437. Each update included one more TVS. Was it a mistake? All the avalanche and TVS devices? I thought this was for load dump protection if the the battery where disconnected from the alternator while running, this is where you get 120v spike right into the rest of your electrical system. This is like worst case situation, where someone was nots smart or something really bad happened like loose battery contact. with a starter motor you have the solenoid breaking the circuit, and on the coil of the solenoid you have a more likely TVS issue because you might have something sensitive after the ignition switch, but not usually. Otherwise both the ignition switch and solenoid are opened up and you get some arcing on the contacts without flyback diodes and a little spike that the battery easily absorbs before it gets back to the DC bus. This isn't my area of expertise, but not sure where you see big spikes like your talking about. I mean yeah put your fingers between solenoid and motor, but how does it jump solenoid other than arcing? Is it because it pulling down voltage on negative side? Can't really find anything on that, and it doesn't seem like TVS diodes are used on starters and ignition coils that much, but some people add them, and it seems mainly to reduce arcing to keep contacting lasting longer and maybe reduce RF.
jharrell 05/07/19 06:14am Tech Issues
RE: Deep Cycle Battery Charging From Alternator

A standard starter motor coupled to an engine will draw a battery down to 10.9 - 11.4 volts. About 4 - 5 times the amperage of a lawnmower starter coupled to nothing. An RV starter armature coupled to nothing like the lawnmower armature in the video draws a fraction of what an armature does in real life. He could have jammed a piece of wood into the starter drive gear to simulate a more realistic test. Lock rotor's duration 1-2 seconds would have blown his numbers right out the window :) Touching the input lead would have yielded 90 - 125 volts not 25. I need to get a scope on my starter system, some of this doesn't jive with the guy who made the video, others asked him about it loaded up and his response: All I have ever measured is starters, windlasses, winches, fridge clutches etc. under load. This was the first time I bolted a starter to the bench unloaded. It was interesting to see the in-rush not change at all (in-rush happens before the engine has begun to turn) and the unloaded average current draw of 100A on a .8kW starter. I've not noted transients any differently on boats while actually starting an engine and releasing the start button than I have on the test bench.. The brushes/motor do create noise on the scope, heck even a stable unloaded battery has noise, but I've not noted potentially damaging transients that approach that of the field collapse of a solenoid. The transient duration can be captured on my o-scope but after talking with the folks at Fluke, Tektronix (my old scope was a Tek), Littelfuse (they make TVS diodes), Garmin, Raymarine etc.etc. they were not concerned with any duration shorter than what the Fluke 289 can capture transients at, which is 0.00025 seconds. I have successfully used my Fluke 289 to fight on behalf of customers for warranty denial too. I was never asked to test it with my scope once they knew I had been using the 289. Any time I come across a random death of electronics the first thing I do is test the boat for transients. It is rare that I seen in excess of 14-16V when the system is well wired but not extremely rare to poke into the low 20's when folks have haphazardly tapped a plotter or sounder or VHF etc. into the engine block for DC negative or engine circuit for DC positive. I have only had a few boats where I had to install TVS diodes and these were very large solenoids on large windlasses causing the issue. Even then it was about 26V on a 12V system. Not a deal killer but worth throwing a TVS diode on..
jharrell 05/06/19 06:39am Tech Issues
RE: Deep Cycle Battery Charging From Alternator

But the video shows there is a difference. Better than nothing. Heavy electric winches are worse yet. A battery does absorb some of the transients but less than 25% of the total. I would imagine a low resistance AGM like a Lifeline would do even better. 120v spike sounds like what happens when you disconnect a battery with the alternator running, I just don't see that making it past a good battery let alone a Lifeline..
jharrell 05/05/19 06:14pm Tech Issues
RE: Deep Cycle Battery Charging From Alternator

Stick finger on starter solenoid wire between solenoid output and entrance to starter motor. Start engine of car being jumped. The one being jumped. Look ma no equations. Do not do this if you have a pacemaker or heart problems. Location matters, the batteries do absorb transients that you would otherwise see at the solenoid:
jharrell 05/05/19 05:42am Tech Issues
RE: Dual 6 volt GC2 batteries and charging characteristics

Despite the Lifeline's higher price I feel like the military provided a vast chasm of advancement for Concorde, right off the bat. The fact that they say 5C charge rate is just fine so charge them at the max rate practical vs everyone else who pretty much says don't do more than C/5 tells me there is something a whole lot different going on. When Concord makes a lithium for recreational use that's when I'll be serious about changing chemistries.
jharrell 04/19/19 06:42am Tech Issues
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