Can you recognize this part?

[nzezgo]

Thanks... was getting ready to buy... and then this ????

I was reviewing a Curtis Controller Manual for the 1268-5403...

... ran into a statement in a 1260-5403 controller failure test doc (attached). Also some info in an installation doc. I think it's saying:
1. a "pre-charge resistor" is already included internally in the 1268-5403 so remove it???
2. that a "suppression diode" is used for pin J1-17 to small solenoid terminal, so it is ok to have a diode... but then in the installation document it says that a "suppression diode" already exists internally.

What's going on with these instructions... do I need a pre-charge resistor between the large terminals on the solenoid or not? do I need a suppression diode between the small terminals on the soleniod or not... totally confused now...



MAYBE I'M READING IT ALL WRONG...

(See attached Image pulled from an installation fault testing document):
"Remove jumpers and reconnect solenoid wiring from the harness. (If suppression diode is present, the non-banded side must go to the wire from J1 pin 17 from the controller. Be sure to check diode functionality with VOM prior to install. If pre-charge resister is installed, please remove. This control is equipped with an internal resistor, and installing one on the solenoid could cause damage to the control.)

I also found in installation instructions the following:
(see attached image)
A coil suppression diode is provided internally to protect two of the drivers (J1-17, 23) from inductive spikes generated at turn-off. To take advantage of the controller’s internal coil suppression diode, the coils must be wired such that the return path to the drivers cannot be opened by any switches or contactors, as shown in the standard wiring diagrams (pages 8, 9)."

Cheers!

[ThreeCW]

Originally Posted by nzezgo

What's going on with these instructions... do I need a pre-charge resistor between the large terminals on the solenoid or not? do I need a suppression diode between the small terminals on the soleniod or not... totally confused now...

You have uncovered some good information when researching your controller.

It seems to be pretty straight forward based on the Curtis 1268 Install Sheet and Manual.

Pre-Charge Resistor:
As per the Curtis Install Sheet, " If pre-charge resister is installed, please remove. This control is equipped with an internal resistor, and installing one on the solenoid could cause damage to the control."
Comments:
The install sheet seems to strongly indicate that no pre-charge resistor should be installed. This is confirmed also in the wiring diagrams of both the Install Sheet and Curtis 1268 Manual ... no pre-charge resistor is shown in any diagram. It is too bad that the Manual did not also specify NOT to install a pre-charge resistor, but you likely have enough information agreement between both documents to NOT install the pre-charge resistor.
A note of interest, on my Curtis Controller model 1219-8405 (~1998 vintage), a 250 ohm pre-charge resistor is recommended in the manual and on the wiring diagram (see attached). So it appears that some Curtis Controllers require a pre-charge resistor to be installed and others have it built into the controller.

Coil Suppression Diode:
As per the Curtis Manual, "A coil suppression diode is provided internally to protect two of the drivers (J1-17, 23) from inductive spikes generated at turn-off. To take advantage of the controller’s internal coil suppression diode, the coils must be wired such that the return path to the drivers cannot be opened by any switches or contactors, as shown in the standard wiring diagrams (pages 8, 9)."
Comments:
The Manual certainly is clear that a coil suppression diode is provided internally to protect the Main Contactor (Solenoid) Driver on Pin J1-17 and the Electro Magnetic Brake / Walk-Away Driver on Pin J1-23. Since an internal coil suppression diode is provided, NO additional external diode is required. Doubling up on the coil suppression can lead to excessive arcing in the Main Contactor (Solenoid) causing premature contact wear and perhaps catastrophic failure. You can read more about this in the attached Gigavac Application Note AN-003. Also see: https://www.gigavac.com/application-...considerations

I hope this helps you decide on what is correct for your application.

[nzezgo]

Thanks ThreeCW. Very helpful... the 1219 manual clearly shows the resistor. My cart didn't have the suppression diode physically on the solenoid to begin with so that is also another good confirmation to leave it off. It did have that pre-charge resistor, but it was between the solenoid and fuse rather than direct across both larger solenoid terminals. In any case, also happy to leave this off. Thanks for your time and knowledge. My next question, in a few days will no doubt be about the walkaway connection on this 1268. Cheers!