Relay differences

[YODA]

Greetings.
First - I have had a few electronics classes. Enough to make me dangerous. I have shorted out numerous things in my long life.

I am adding a new grip to my tractor to operate a hydraulic valve, I am told I need a relay as the membrane switches in the handle wont handle the full valve current of about 30 amp. The part number for the John Deere OEM relay used with the grip I am getting is.
AT308380 - Relay - RELAY, 280-SAE J1744
these things are very expensive. From what I have read they are a special micro relay. However I am being told I can use a
Ulincos Auto Relay U1914 or JD1914
another one folks used is
CM6331

I don't doubt the folks have good working units, but I am very curious about the differences between the AT308380 and other standard 12V automotive relays folks are using. Can anyone help? If I goof I ruin an $80 wiring harness that has the grip switch built in.

If there is something special about this relay to work with the membrane switches is there an equivalent with the base plug wiring available?

The valve specifications are here. I am getting the 12 volt version http://www.argo-hytos.com/fileadmin/user_upload/Datasheet_RPE3-06_ha4010_EN.pdf

Thanks

 

[Bluejets]

Don't know where you get 30 amp load from as only detail I can see in the link you provide is "rated current 200mA".

Perhaps you can provide more detail.

Other than that just use a standard auto relay. Assuming your system is 24v then use appropriate voltage relay.

Note that any advice given here does not imply any "goof" by you can be avoided.

 

[YODA]

Ill check with agro-hytos in the morning. Meanwhile is there something special about the AT308380 type relay. I think the foil membrane switches are rated for 30mA. Ill check with JD on that tomorrow too.

 

[kellys_eye]

If the membrane is rated at 30mA you may need two relays - a low current device connected to the membrane switch and a standard 30A (contact rating) relay to power the circuit you want.

The alternative would be to use a switching transistor but that's an added complication.

Either way you'll probably end up spending close to the $30 the JD relay seems to sell for anyway.

https://globalpartszone.com/john-deere/at308380-1.html

 

[YODA]

Per several JD wiring diagrams the harness (used on numerous units) is connect to the foil membrane switches plugs into another very expensive harness with fuse/relay block that has the relays installed, and they then power the JD hydraulic valves. I guess what I need to know, or where to find the specifications) is what power does this JD relay require to activate. I.E. what current draw is the switch seeing when activated.

I hope I am explaining myself correctly.
Thanks

 

[73's de Edd]

Sir YODA . . . . .

Looking between the specs of both of your sub relay substitutes , they meet the specs or even exceed the power carrying capacity specs of that pricier sub compact half relay.

Your "sensitive switch" loop circuitry will only be carrying the paltry ~2 watts that is required to activate the 12V coil of the principal POWER switching relays HEAVY contacts to the valve.

REFERENCING . . . . .



73's de Edd

 

[YODA]

Thank you so much - there may be light at the end of the tunnel.

 

[73's de Edd]

Sir YODA . . . . .

" foil membrane switches are rated for 30mA. Ill check with JD on that tomorrow too."

With due consideration of your doing your own researching out, in order to find the current passing thru the membrane switch.

I'll just bet you that "ole' Joe Blow on the factory phone help line can't even start to give you that / correct info.

What you need to do is track down the two wires associated with the connections to the membrane switch.
Then put a voltmeter across them to confirm a DC voltage, then activate the switch and hear / confirm the
valve activation.

At the time that the membrane switch is pressed the voltage on the metering voltage should drop to ZERO.
This further confirms that you are at the right connencting points for the membrane switch.

Then you switch your metering to 1 amp DC range and when you then place the probes back at the prior test points, the valve should operate at the instant of both probes contacting . . . as you are then simulating the closing of the membrane switch.
If that happens your meter is set up right and you have the probes plugged into the meter at the proper points.
(That variance is usually only when you are using its 10A range)
I'm not expecteing a meter read out until you switch down and try the same pocedure at a lower 100 milliampere setting.
Then you can confirm the actual current that your switch is passing thru it in milliamperes.


Confirm . . . . . .

73's de Edd

 

[dorke]

I wonder where did you get the 30A info from?
The data sheet states 2.7A,so you can use a "smaller" relay ,a 10A one will do fine,
It will cost you less than 2$(Omron,Panasonic).
see here.

https://www.mouser.com/Electromechanical/Relays/Automotive-Relays/_/N-b19z1?P=1z0x3ubZ1z0x3x8&Ns=Pricing|0

 

[73's de Edd]

I also read the current pull of the valve as being 2.7 A , but then just compared that value to what the "overkill" cushion margin, that the relays contacts would be providing at 30 A.
And yes, it looks like that OMRON at its 10A would be a like 1/2 size replacement with out all of the carpetbagging profit being made by the other supplier.
http://www.mouser.com/ds/2/307/en-g8v-843959.pdf

 

[YODA]

Thanks Folks Argo-Hytos confirmed the current drae, and Jhon Deere had no clue what their switch was rated at. They did say the relay I quoted was the one they use, The valve has a common and hot lead - interchangeable per Argo-Hytos. They both look the same coming from the valve body on each side. I know I will need two relays, but now I am wondering how to wire them up. Is there a diagram somewhere I could use.

Thanks so much for everyone's help.