Motor contactor "black box"
Motor contactor "black box"
(OP)
I don't post here often, but enjoy reading the posts concerning motor and controls- I've spent the last 40 yrs on low voltage D.C instrumentation........
Had a customer call the other day complaining that his Eaton Cutler Hammer size 6 contactor would not pull in- he gave a model no.A10JN0-C1. From what I could conclude from his description, there must be a rectifier within. He stated that there was a "black box" in the line between the coil input terminal and the rectifier (another box!)
I tried several internet searches but found nothing. I've had numerous black box descriptions thru the years that turned out to be capacitors, power supplies, relays etc, Any idea what this "black box" is? Perhaps a fuse holder?
It seems as though he was ohming things out and stated that there was 5k ohm across this "box".
Had a customer call the other day complaining that his Eaton Cutler Hammer size 6 contactor would not pull in- he gave a model no.A10JN0-C1. From what I could conclude from his description, there must be a rectifier within. He stated that there was a "black box" in the line between the coil input terminal and the rectifier (another box!)
I tried several internet searches but found nothing. I've had numerous black box descriptions thru the years that turned out to be capacitors, power supplies, relays etc, Any idea what this "black box" is? Perhaps a fuse holder?
It seems as though he was ohming things out and stated that there was 5k ohm across this "box".





RE: Motor contactor "black box"
I believe I have the latest eaton parts book and can't find that #. It could be rc snubber if the coil is feed from solid state device. You need the coil voltage, ac or dc and the contactor #. On that size contactor, I have seen rectifiers used also.
good luck
Dave
RE: Motor contactor "black box"
RE: Motor contactor "black box"
I will see if I can obtain more info i.e. a good p.n. and the control voltage used.
He said that the coil is marked 110 a.c 50/60 hz, 110 d.c. From what he described it sounds like there is an internal rectifier, with a "small blck box" between one of the coil terminals (A1 or A2) and the rectifier. Don't know whether or not the box is holding the coil out- he thought it might be a fuse.
RE: Motor contactor "black box"
That contactor was obsoleted before the age of the internet, so documentation on it is going to be paper, if it still exists.
"You measure the size of the accomplishment by the obstacles you had to overcome to reach your goals" -- Booker T. Washington
RE: Motor contactor "black box"
However, I don't think that the timer is usable on a size 6 starter and not useable on DC. (No ratings are given)
All current large CH starters use a two winding coil and special shorting contacts. When the starter pulls in the shorting contacts open and place the holding coil in series with the pull in coil. This is the arrangement I have seen the most often with DC coils.
Is it really a size six starter or did the customer make a mistake there?
how large is the motor and what does it drive?
Your customer may not be the first person to see this starter since it failed.
Bill
--------------------
"Why not the best?"
Jimmy Carter
RE: Motor contactor "black box"
C-H stopped selling these 20 years ago (yes, it's been that long...!).
"You measure the size of the accomplishment by the obstacles you had to overcome to reach your goals" -- Booker T. Washington
RE: Motor contactor "black box"
Bill
--------------------
"Why not the best?"
Jimmy Carter
RE: Motor contactor "black box"
Come to think of it, that may not have been a bad plan to lose some weight. Should have thought of that...
"You measure the size of the accomplishment by the obstacles you had to overcome to reach your goals" -- Booker T. Washington
RE: Motor contactor "black box"
I did not realize that these contactors were that old, or early obsolescence due to failures like this? Absolutely nothing on the web (provided that the part number he gave me is the right one). I may try to call Eaton and see if they have old schematics available on line. He was firm on the size 6, 540a/ 400 h.p.
Just curious, does anyone have a ballpark guess as to the va burden from the coil of a contactor such as this- on the a.c. side if fed from an a.c. source?
RE: Motor contactor "black box"
But if it has the DC coil and rectifier / optimizer circuit, there is no inrush, that's why they used it. So it will be in that 250VA range from an AC draw standpoint. When you order thre A-B version with the DC optimized coil, it comes with a 250VA CPT as part of the assembly to power the coil.
"You measure the size of the accomplishment by the obstacles you had to overcome to reach your goals" -- Booker T. Washington
RE: Motor contactor "black box"