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

Ok, I just tested the two solenoids.

One is a White Rogers 70-111224-5. Other markings on it say 91US and coil 12vdc cont. It was likely in use on my fathers boat at some point, which he got rid of several years ago. was it made in the USA in 1991??, very possible.

Unlike the photos shown in the link below the large output studs are copper colored. The 224 means ' Isolated coil, Cu NO and Ag NC contacts'
I guess NO and NC mean normally open and normally closed. Copper open Silver closed.....

https://www.mouser.com/ProductDetail/White-Rodgers/70-111224?qs=oTUMjHQZwx0r5D6bUOoJNg%3D%3D

https://www.mouser.com/datasheet/2/459/R-4003web-335062.pdf

It drew 0.9 amps at 12.43 to 14.6 volts
It drew 0.79 amps at 10.78v
It drew 0.57 amps at 9.78 volts
It drew 0.4amps at 8.69v
0.36a@7.63
0.31a@6.07
0.23a@4.8v
My voltmeter turns off at 3.4v and still the magnet stayed energized. No 'un'click.

I disconnected power to bucker, and it clicked off.

Then I reattached power at 3.5v and no click. It did not click until 7.2v, but relatively weakly. When I hit 10.17v it clicked again with more authority.

I was also measuring 0.01 to 0.1 Kohms resistance on the way down (No load), more resistance with less voltage applied, but after that reclick at 10.17v on the way back upto 14.6v, there was 0.00k ohm resistance forever after. Not sure what that was about. Could be 2 decades since this solenoid was last energized.

The Other Solenoid is also from my Dad's boat, and has two trigger terminals, and did not work at all when I put 13volts to these. when I grounded one lead on the mounting feet and touched the red alligator clip to one terminal with no result, then the other, it sparked and violently snapped, jumping an inch off the table, and was drawing 3.6 amps at 14.42v. This originally black and partially spray painted red solenoid has no markings on it other than AA JA 12v, Made in the USA. Slightly larger and heavier than the White Rogers and it too has reddish copper colored output studs. Much darker looking than silicon bronze or brass.

The 3.6 amp draw makes me believe this second solenoids is NOT a continuous duty solenoid, it only lowers to 3.4 amps at 12.8v. I did not leave it energized long enough to notice any heat build up, but I'm sure it would have to at 4 times the amp draw of the White Rogers.

I did not run it through the 10 amp voltage Bucker to see if it opened at lesser voltages or what minimum voltage it fired up at. I kind of feared frying the bucker when the coil would de-energize.

So anyway it is obvious that less voltage reaching electromagnet causes it to draw less amperage and as such the contacts are not forced together nearly as strongly as compared to 12 volts or higher. Passing partial starter motor current through it at 10v is not advisable and likely the cause of premature failure.

The sheer violence with which thi second red solenoid activated, means it likely is not continuous duty but is intermittent duty, like for a starter motor.

I actually touched the test leads to the red one's smaller contacts firs, and with no result was eagerly looking forward to disassembly. but when I clipped a test lead to the mounting feet and then touched the small contact.....SNAP!

Still tempted to drill out the rivets and have a look see.

Anybody opened one up and have Pics?

Be interesting to see the difference between continuous duty and intermittent duty contacts size and see the failed contacts.

I never considered the starter battery voltage dropping as attributing to the contact resistance inside solenoids, but it does make a lot of sense.

I've got a couple of older solenoids and can feed them different trigger voltages and see how much amperage and total wattage the electromagnet requires to hold contacts closed at 10.0v vs 12.2v, but don't see myself measuring resistance across them under load, at those different voltages.

I've always sought a trigger circuit which was not live until after the engine started, next best was one not live during engine cranking, but would be on with the ignition.

I never wanted any delicate electronics hooked to house battery to get cumulatively damaged by the voltage spike when the starter motor is disengaged. but I've been effectively been doing that for 5 years as my house battery and starting battery are now one in the same.

I once installed a user provided solenoid, and that thing got excessively hot quickly, passing just 30 amps. I realized much later it was likely a latching solenoid that needed a momentary burst of 12vdc to latch or unlatch, not continuous 12v to power an electromagnet.

Wire in parallel but do not trigger in parallel a Ford starter solenoid. It needs a dedicated signal to operate. 700 Amos 15 seconds durability.

theoldwizard1 wrote:

mchero wrote:
Cole Hersee link looks interesting. Continuous duty indeed but how many amps? I'm looking for 300 amp plus.

Why so much ?

If its purpose is to isolate the house batteries from the starting batteries during cranking and when the engine is OFF, it will only be ON when the engine is running and you are trying to charge the house batteries from the engine. I am certain that your engine alternator can not generate anything near 300A !

Personally, I would rather have a DC-DC charger. It will not allow reverse flow of current AND it will properly apply a multi-step charge on your house batteries.

Let's say my chassis batteries are low. Remember that Aux Start switch on panel next to driver. If you push that switch and crank her up you can EASILY surpass 200 amps.
I know, one day we where at Salisbury state beach MA. Spanking new 2019 Discovery backed into site across from us. Two guys plugged her in and shortly afterwards were walking around power pedastal with puzzled look on their faces. I walked over and asked what was up? "No lights inside, nothing!" Opened up battery bay and found 300 amp protecting house batteries blown! I asked them if they had a starting issue earlier? They responded yes! I asked them if they used the Aux. start switch to get the rig started, they responded yes.
So chassis batteries low, they pressed Aux start switch while they cranked it over. Started BUT blew 300 amp fuse.
That solenoid does indeed charge house batteries while driving down the road BUT will ALSO pass current from house batteries to main engine starter


Thus the reason I'm looking for 300 plus amps.

What the Discovery owner SHOULD have done, and others in like situations is hold down Aux. start switch for a couple of minutes BEFORE starting rig. Just like jump starting a car with flat battery. You need to wait a couple minutes before starting.

I always fire a large solenoid with a Bosch relay.


And for God's sake put a free wheeling diode across the power contacts.

Silver contacts are an inlay. And contact welding yanks a chunk out of the bolt or the ring. Ugly to see.

MEXICOWANDERER wrote:
I was asked to comment on this. One condition was not mentioned. And it is a condition that will burn any solenoid. If the test is not verified then solenoid burnout is assured -- even 300 amp modeks.

The solenoid must not remain engaged as the engine is cranked. Check that the small ignition post goes dead as a doornail as the engine starter motor is cranked.

A five dollar fender mounted plastic body solenoid is more resistant to burnout at 700 amps rating than a hundred dollar 300 amp continuous duty solenoid. Why? Because when the engine is being cranked that so I avoid no longer utilizes 12 volts. Try 10 volts. Weak pull in, chatter and contact arcing.

Putting in a flywheel diode reverse orientation will help correctly connected solenoids live longer. More info about flywheel diodes on the web.

Verify correct connection to ignition B Instead of Ignition A

I am minus a laptop so no more posts

David ... I think you may have really hit on something above regarding the pull-in coil voltage on the solenoid dropping during engine cranking ... which may cause solenoid point "chatter" while high current is being passed between the solenoid's points. Point chatter will of course cause arcing across the points and subsequent corrosion of their surface. This corrosion built-up on the points during uses will over time increase the resistance across the points, which in turn lowers the charge voltage that the coach batteries are exposed to from the engine's alternator. Hence -> under-charged coach batteries when you arrive at the campsite after driving for awhile.

I'm on my 2nd Trombetta solenoid in over 10 years. I attributed the failure of the original stock solenoid and the 1st Trombetta solenoid to the points becoming corroded over time. However, I couldn't understand why the 1st Trombetta solenoid - with it's silver coated contacts - would be subjected to corrosion. Perhaps even silver can degrade/corrode from any arcing that low pull-in voltage based point chatter may cause.

Here's the Trombetta solenoid model that I'm on the 2nd one-of in our motorhome: https://www.trombetta.com/wp-content/uploads/2019/07/bear-family.pdf

Perhaps this would be a more robust Trombetta to use that I didn't know about - or didn't exist - when I began using Trombetta solenoids in our motorhome: https://www.trombetta.com/wp-content/uploads/2019/07/TR-19105_PowerSeal-ContDuty_SS-v4.pdf

Yeah it's about a million times "Smarter" than the costliest smartFRAUD.

It mimics the BCI recommended formula. Let's hear from ANY manufacturer who disputes this formula including Trojan or Rolls & Surette.

Keep pressing the DESULFATE BUTTON 679 TIMES IF NECESSARY. This is maroon thinking at its basest.

Roger Mex
Thanks ever so much for the detailed explanation! I'm starting to get it!
RM

Any
Any
Any

Charger that can reach 16 volts while meeting 5% amperage

Light bulbs hooked in parallel if necessary to allow correct current to pass

100 watt 12 volt bulb will allow close enough to 9 amps constant current
50 watts will allow 4 amps to flow...

Enter screw-in regular lightbulb with positive from battery
Exit the other base screw and continue on to battery positive.

Negative is connected direct from battery minus ground.

By paralleling 100 and/or 50 watt bulbs you can make a CURRENT regulator. Constant current.

Test
If 2 100 watt and one fifty watt bulb are connected in PARALLEL how many amps will flow at 16 volts

OK. Now what size battery bank in amp hours 5% would these three bulbs in parallel be ideal for.???

These bulbs are available online or at NAPA parts stores. You may have to order the bulbs. Plastic or ceramic bases are available at Hardware Stores.

What do I use to charge at 5% total amp hour Mex?

Today I disconnected the Xantrex from both AC and DC feeds, let it sit for 15 minutes, reconnected DC and flipped the AC breaker on. Charger kicked in but no remote panel :(
Was hoping the lack of AC or DC would "reset" the Xantrex Freedom 458 "possibly" restoring communication to the remote panel.
Next step, inverter service time.