I need an education in soleniods.

I have a diesel engine which has an emergency shut down solenoid. The solenoid is a General Electric CR9500A101E2A. From what I have found, this is a 110V AC solenoid. The electrical system on the engine is 12V DC.

What is the diference between an AC solenoid and a DC solenoid?

Detroit Diesel want's $125.00 for this solenoid. What parameters do I need to match if I want to substitute another solenoid for this one?

thanks and have a great day.

Mike.

 

If it's any help?, a quick google finds this http://66.102.9.104/search?q=cache:u...0A101E2A&hl=en. But this is from a cached page, and it doesn't seem to appear on the current pages :cry:

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You Said,
Other then the physical properties of the solenoid,(bolt pattern, pin out ect..., Match the amp and voltage ratings.
Stick with DC.
If you can do that, then your well on your way.
Also, these manufacturers all use parts that are readily available to them, and you may find what you need from generic auto supply store.
Good Luck

 

Does this engine drive an AC generator? If so, is the solenoid powered by AC?

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Ron

 

it is part of an AC generator, but it makes more sence to power the thing off of the engine's 12V electrical system. the next engine off of the assembly line may be going into an 18 wheeler truck with no AC generator.

what happens if you power up a 110V AC solenoid with 12V DC?

 

I would have thought very little?.

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(1)
If it's driven by the 120vac generator power (the voltage holds the solenoid valve open), there's a reason for it. The emergency shut-down is for a generator problem, not an engine problem, so a 12v solenoid would be a dangerous replacement unless you added a transformer, etc. to the original circuit, powered from the 120vac.

(2)
Dang. It amazes me how folks will spend $30,000 on a vehicle, put 96,000 miles on it and then bitch when they have to shell out $120 for a water pump or $35 for brake pads or .....

If you have a diesel-powered piece of equipment, especially if powered by Detroit, Cat or Cummins, why would you not expect to pay a few bucks for an original replacement part? And why would you want to screw around with some kind of slip-shod jerry-rig for an EMERGENCY SHUT DOWN solenoid? Next, someone's going to want to substitute for the sprinkler heads on their fire protection system or use water in their brake system or cheesecloth for their emergency parachute with that kind of thinking.

(3)
Dang, Ron. Am I becoming the curmudgeon now? Are you slipping?

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Dean Huster, Electronics Curmudgeon
Contributing Editor emeritus, "Q & A", of the former "Poptronics" magazine (formerly "Popular Electronics" and "Electronics Now" magazines).

R.I.P.

 

The only real difference between an AC solonoid and a DC one is the thickness of the laminations of the core. The AC core has thinner laminations to reduce eddy currents. The DC resistance of the DC solonoid is of concern. The AC solonoid will work on DC but might draw too much current.
BTW, solonoids are expensive, no matter where you buy them.

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I'd second Dean's thinking to some extent. The shutdown is either for overspeed or just simply to shut the engine off. Either case demands a high degree of reliability. Imagine loosing engine cooling then having the shutoff solenoid fail. If it's a fire pump it would be awful to have the engine shut off because of solenoid failure - at the worst possible time.

Not sure what your application is - just encouraging some caution here.

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stevez

 

Dean, that's exactly the reason I asked the question. And you may be becoming a curmudgeon, but I definitely am not slipping. Did you see my post to mstecha a couple of weeks ago? I was downright cranky. ops:

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Ron

 

This particulat emergency shut down solenoid is only energized if the engines water temperature get too hot or if the oil pressure gets too low. if either of these occure, it is energized to release a catch which lets a spring loaded flap valve close and choke off the engines air supply to shut it down. it need not be rated for continuous duty. an overspeed sensor would be something i would like to add to the system later.

this exact same system would be put onto a PTO unit where there is no generator. i still think it would be powered from the engines electrical system, though i have nothing to back that up except for the incredible interchangeablity of parts between the diferent modles in the Detroit inline 71 series.

Wow, Dean. you are really laying into me there. i suppose you always take your car back to the dealer for parts and service? i wish i was as rich as you so that i could afford that luxary.

it sounds like there is no real problem using DC to energize an AC solenoid. any heavy current draw would only be momentary. choke off a Diesel's air and it won't run but for 5 seconds or so. besides, as soon as the fuel pressure drops below 10#, the whole shutdown system is deenergized. so long as the wires can handle the current, the batery should have no problems with a momentary heavy current draw.

thanks for the help and information. i appreciate it.

Mike.

 

actually, i was wrong. i just checked the Detroit manual and the wiring diagram for the shut down system does show that is is attached to the battery.

thanks again,

Mike.

 

DigiKey lists some solonoids. You will have to check the data sheet to see if any are suitable.

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I have a bunch of solenoids and can say for sure that the AC solenoids do not work on DC! Small twitch as the current changes and then no force at all, although the coil current is substantial. I don't have a magnetics explanation, but that's the reality of it.

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I thought what I'd do was I'd pretend I was one of those deaf-mutes.

 

It is almost a given that your solenoid is 12V or 24V DC.

Detroit, Cat, Cummins, and many other engine manufacturers, would have their engine protection systems independent of any generated AC power.

They first protect their engine, and then if part of the package, the generator.

The generator has its own protection for overload and heat ect....

And BTW, Detroits, have the solenoid energized when the engine is running, so when you have low oil pressure, or low coolant, or whatever,,
all that happens is the solenoid is deenergized, and being spring loaded, the fuel valve/bypass, is shut off.
Newer engines do this differently, each unit injector , which have there own solenoids, shut down.
In any case,

GOOD LUCK.