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Master Solenoid sticking

RV10inOz

RV10inOz

Well Known Member
I need some help!

I have a master solenoid, Cole Hersee 24143 which is 200A continuous rated which supplies the main connection of power from the battery to the rest of the plane.

the solenoid will switch on and off all day, however after flying (and an engine start) when the master is turned off the solenoid stays closed for anything up to a minute or so.

Am I likely to have contacts that are welding closed? Is there a residual magnetic force keeping it closed?

Have I done something wrong here? :confused:

Cheers

DB
 
solenoid

Check to see if your clamping diode is shorted. do you have the diode installed correctly? Temporarily disconnect it and see if your issue is resolved. These things will leak to ground when hot. Just found almost the same issue on a friends Grumman. It was a leaking diode killing the battery on the starter solenoid.

Hope this helps,
Chris
 
No Diode problems. And yes its installed the right way around, otherwise they vapourise!

I also have a diode on the starter solenoid, however this is the master we are having issues with.

Its the solenoid STICKING on that is the problem. I am wondering if the starter motor could be drawing well in excess of the cont. rating long enough to weld the contacts a bit.

Cheers

DB
 
You may be on to something there. You can over current the master during starting and cause it to stick. I installed a better battery (PC680) and the problem went away. Maybe your timing is too high and causing kickback? Anything that can cause an extra load during starting will cause it to stick.
 
RV10inOz said:
I need some help!

I have a master solenoid, Cole Hersee 24143 which is 200A continuous rated which supplies the main connection of power from the battery to the rest of the plane.

the solenoid will switch on and off all day, however after flying (and an engine start) when the master is turned off the solenoid stays closed for anything up to a minute or so.

Am I likely to have contacts that are welding closed? Is there a residual magnetic force keeping it closed?

Have I done something wrong here? :confused:

Cheers

DB
Click to expand...

Get a new one and change it out. It will not fix itself.
 
I had the same issue, change it out. They are not the most precise piece of equipment. It's real hard to hook one of them up wrong so go easy on yourself:D
 
Ahhhh you guys crack me up :D

This is the second one........ it is a much bigger battery, ;) the 680 is my avionics back up:p and the main is a 925.

oooohhhh and yes I have hooked them up right!

I might just phone the folk at cole hersee now and ask for tech help.....as they are at work at the same time as I am off to work!

Any more suggestions are welcome. Coz it just Don't make sense!!!! (as Foxworthy would say)

Cheers
 
The contacts we use in the industrial world don't weld very quickly. Is there another energy source that could be tied to the solenoid? Solenoids don't take much to "hold" after they have been fired - that is, if they are like those we use.

I look forward to learning your resolution.

Cheers!
Michael
 
I look forward to learning your resolution.
Click to expand...

And so am I.....

I have installed a really serious solenoid now 225A continuous rated with 600A inrush capacity from Cole Hersee........what more can I do? I am sure the coil is collapsing.....well I think I am, if I cycle the switch I can hear the springs and the slug banging in and out.....but the contact stays made things are still alive :eek:.

What kind of solenoids has everyone else been using?

DB
 
RV10inOz said:
if I cycle the switch I can hear the springs and the slug banging in and out.....but the contact stays made things are still alive :eek:.

DB
Click to expand...

This sure does sound like the contacts are welding shut-----at least partially so.

I would look for something that is causing a low voltage problem in the start circuit-----engine ground maybe------often times low voltage causes the amps to skyrocket as the load tries to pull the same wattage, which is the real measure of work done.

W=AxV
 
Check Volts/Amps!

DB

I would hook up some instruments (Volts/Amps) before coming to any conclusion! I learned that if contacts stick, they stick! (and they stick very well and they will not come appart that easy). Is there anything holding that solenoid in? (check the Volts/Amps !)

Hope it turns out to be a simple Gremlin.

Regards, Tonny.
 
How about orientation of the solenoid, is it mounted right side up so the plunger and points are assisted by gravity to disconnect when they are de energized? Could you have a small current leak to ground on the solenoid coil when your master is turned off, perhaps a light bulb or something?
 
Best Suggestion So Far from Belgium!!

Pilottonny said:
DB

I would hook up some instruments (Volts/Amps) before coming to any conclusion! I learned that if contacts stick, they stick! (and they stick very well and they will not come appart that easy). Is there anything holding that solenoid in? (check the Volts/Amps !)

Hope it turns out to be a simple Gremlin.

Regards, Tonny.
Click to expand...

Well said Tonny.

I would use a digital multimeter, set to volts, and check for residual voltages across the coil of the solenoid. Also I would also put the multimeter in series with the solenoid coils (means breaking the circuit) set to amps and check for any residual current. Check for residual voltages and currents after the master is switched off. These residuals combined with any sticking of contacts due to excess currents could be enough to hold the solenoid closed.

Good luck and let us know the fix and the problem if you find it.

Tony
 
Ok folks, appreciate your input, and here is some more brain fodder for you all.

The solenoid is NOT carrying any ground leaks. Even the new 225A(600a peak) solenoid is doing it and I have made it stick, and then pulled teh groinding wire off the terminal....

Now apart from getting it to stick and removing the grounding source and proving that I did the following tests.

1. master on, cranked engine but did not start it. Did this several times and it would not stick, leading me to suspect the problem is not related to starter motor current draw.

2. Started engine ran every thing up as normal, shut down and it stuck, cycled the coil a couple of times, removed ground source and still stuck, tapped the solenoid with the handle of a screw driver a few times, still stuck. About 15 seconds after this, it dropped out.

Now the only thing I am observing is that large currents can flow when the VSR switches the batteries together during charging, but the VSR has a current limiting feature of 60 amps with a peak of 150A for a few seconds. None of this is outside the specs for any of the equipment installed be it alternator, VSR or the solenoids.

I am at a loss. I will start a process of elimination with isolating the VSR and second battery, see what happens, the reintroduce the second battery. If and I can not see how, but if the VSR is somehow to blame it may become a job for a big Diode. Effectively the VSR is no different to a solenoid being used for switching multi battery circuits anyway, its just smarter at balancing loads and current limiting.

Power drawing is attached for anyones interest.

Cheers and keep the comments coming!

DB

4525920200a11242135799l.jpg
 
AHA, more information about the system-------

O.K., try this ------ disconnect one battery, and the associate wiring and control box, and go start the plane, see if the solenoid sticks.

If it does, reverse the process, and try operation on the other battery only.

Can you elaborate a bit on the VSR is??

Good luck.
 
Gooday Mike

Yes that is our next test, although the VSR is really only a smart relay.... just brings the second battery in when the voltage of the main one is up again after charging, and allows the second one to charge. Its like a one way valve for electrons!:)

I am also going to put a removable link in the +ve and -ve coil leads so that I can 100% isolate the coil........ just to be sure there is nothing sneaking in there. I doubt it as i can hear it..... but its the best way to be 100% sure.

Cheers!
 
Seems unlikely but ..

If the contacts are welding it may be caused by hi inrush currents from large capacitive loads. IIRC the Xcom radio install kit came with a massive capacitor for supply filtering, do you have something like this?

If this is the case you may need to install a low value series resistor (say 0.1 ohm) in the offending circuit.

I have seen 25Amp switch contacts weld - but I would not have expected it with the contactor.

Doug Gray
(In Canada visiting my son - heading for Osh...)
 
Doug said:
---- a massive capacitor for supply filtering, do you have something like this?
Click to expand...


I had the same thought, but was figuring the cap was leaking voltage back into the solenoid coil-------and keeping it energized for a few seconds???

But, he can hear the slug clicking in:confused:
 
It is possible to latch up a relay with reverse current leakage in more complex wiring arrangements and this could well be the case but I was considering contact welding only.

It is somewhat unclear to me but I had understood that the contactor remains closed even after removing its ground and after removing the diode - fully isolating the solenoid.

Doug
 
STOP LOOKING - I FOUND IT

The stupid engineer :mad: (might have been me ;) )who designed the power system had in his mind the VSR also acted like a Diode...........well it does in some respects but it allows the two sides of the VSR to be connected for a minute with an OFF delay, normally for verification of a balanced load and if the main battery voltage was low it would open.

Well I have the " A " terminal wired (and drawn) on the wrong side of the solenoid. So its now easy to fix!

DB :cool:

So thanks for everyones input......... just goes to show if you try hard enough you can solve anything.
 
Lol...so much for me telling you it couldn't be you!!! I did have an intermittent one, Got tired of rapping it with a wrench ;) and replaced it.
 
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