ycas

[nique]

I have ycaso230e that is giving me a current overload alarm on both circuits. all volts are fine and when the unit runs for the seven seconds before trip it is reading twice the amps that my amp clamp reads. the motor protection modules are giving me a readout of 1,2and H. which according to the book means I have a bad mpm. since both circuits were operating yesterday I have a hard time believing that both mpm went bad at the same time. any body seen this before?

[njbiker66]

I ran into this before. Shut the chiller down and open up both covers to the the compressor terminals check the 4 or 5 small 14 gauge wires for breaks in the wires and make sure your connections are cleaned and tight. Also check the sensors/ Thermistors for the correct resistance.

[ImpellerNut]

Is it across the line or wye delta?

[nique]

wye delta, checked all the wires and sensors and all are ok. stole a motor protector from another unit with the same result.

[ImpellerNut]

I don't know why they woud be incorrect, but did you check the dip switches on the MPM to see that they're set right?

The Wye-delta contactors are pulling in in the proper sequence right?

Also, the code you are getting leads me to believe you are not capturing the correct thing. After it trips, you should see a single number 0-8 or an E.

[michael26]

Check the input card for those inputs. If those are the only two things on that card I would suspect a bad input card. And check the settings. I have a 200 that is wye delta and it only reads half the amperage and had to be set up that way.

[nique]

here is the update. I decided that the eprom had lost the program so I reprogrammed it and it would not hold. changed out the motherboard and eprom holds program just fine. it is like you said michael26 it reads half the amps. the motor protection module has nothing to do with what the board sees when it comes to amps. so everything is working just fine. as a side note jc has got to be the most difficult of the big four to deal with. they need to ask themselves why any body would ever install a chiller that they refuse to give support. I can call tech support at any time for trane, carrier or mcquay but it takes a small miracle and some blatent lies to talk to support at jc.

[nine o]

Professional member can confirm. The displayed amp reading is adjustable. Just had a ycas0110 that displayed about twenty percent lower than actual amp draw. A minor adjustment in micro and the displayed amp draw is spot on. The micro also uses this to load limit machine, pretty important to have this calibrated.