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Originally Posted by chrisrich28

Hey i have a maqcay 210 ton and it's giving me an alarm that says overvoltage cir 2 any thoughts on that

Sell them a York!!

Hey i have a maqcay 210 ton and it's giving me an alarm that says overvoltage cir 2 any thoughts on that

Do any of you have a calibration procedure you can send me on this?

I haven't been back. The compressor loads and unloads great. Its the position sensor giving us trouble. I'll let you know, its working for now and we may wait till its cooler outside to get into it.

The original design SV Indicator had a ball on the end of its shaft that was a harder material than that of the SV shaft. That ball would groove the shaft in it most common SV load position and cause false load conditions and sensor errors. The newer Indicators have a broader, softer tip to ride on top of the groove to read position better. If you are still having issues after Indicator replacement, I suspect the slide valve arm and internal linkage have become loose or have fallen off. Can you manually load and unload the compressor to reach min and max amps? If not, the oil seperator will have to be removed and the slide valve checked.

Thanks, ascj. I received the email. I'll read through the manuals when I get a few minutes.

Also, thanks to the admin for removing the uploaded picture.

Might I send that information to my email

Originally Posted by ascj

Wow....you need some new manuals. Check your email.

You said it trips out right away? What is the slide position showing on the Microtech? Does it even try to start?

Its an interminent trip on slide valve sensor failure. When I reset and started the chiller, the display showed -21 for fully unloaded. I preformed the calibration procedure and the display showed 1 for fully unloaded and 99 for fully loaded. The next week the customer called again for no cooling. Another tech found the same circuit tripped on slide valve sensor failure. The sensor was replaced about 2 years ago and I'm told it randomly trips on that same fault. The trips are now happening more often.

Wow....you need some new manuals. Check your email.

You said it trips out right away? What is the slide position showing on the Microtech? Does it even try to start?

Originally Posted by ascj

You calibrated it?

What mA reading you getting from the sensor?

It was replaced by another tech. I did calibrate it on a call after it tripped. I used the following procedure and did not measure mA. I haven't been involved as much with this chiller as it is outside of my normal area but I worked on it a fair amount.

Edit: It will not allow me to remove the picture. I realized after uploading it has the written text on the bottom. I'm using tapatalk.

Originally Posted by Sicofthis

I'm having the exact same problem with the circuit #2 continuing to trip despite having replaced the slide valve sensor. It trips intermittently. Can I get a copy of the PDF or the document number?

You calibrated it?

What mA reading you getting from the sensor?

I'm having the exact same problem with the circuit #2 continuing to trip despite having replaced the slide valve sensor. It trips intermittently. Can I get a copy of the PDF or the document number?

I'm kinda sad that half of these model chillers we take care of got taken away from us. They really are interesting and challenging machines to work on!

Freonick thanks for the pdf! Great info.

As far as wear.....I only have had issues with this one compressor. And I have only seen the compressor lock out once on "slide valve fault". That was the last one that the head took a crap. All the rest of the lock outs occurred when I wasn't there.

The original had the ball bearing end. Inspected slide when I replaced it.....didn't see any grooving on it. But replaced it with the new and improved model. Also replaced all wiring...to rule that out. Fine for about 4-5 months, then repeat failures. New model has alot bigger end on it. We will see.......it's been ok so far.

wow. i have a chiller i recalibrate those slide valves annually. maybe i should pull them. i can't believe you're seeing that kind of wear!

I think Rick is giving you the holy grail!

check your email.

Replaced the slide valve sensor assembly, again today. When I pulled the old one out, I noticed it was worn. Seems pretty bad for only 4 months.

What eats me......2 year old chiller. Circuit 2 compressor constantly with slide valve faults. Circuit 1 fine. Replace slide valve sensor with new design. Worked fine for 4 months. Then head dies. Replace with another new design. Results unknown.

I attached a couple of photos. The first is the two older sensors. The top is the original and the bottom is the replacement. The next photo is the one I just put in. The third photo shows the last replacement wear at just 4 months.

Why McQuay can't tell me why they keep redesigning the sensors?

Don't overtighten screw on plug. Leave cap off micro switch till calibration is complete,When complete then power down unite replace cap and plug,then turn power back on.To calibrate Set compressor slide to 0% then press miro switch till it blinks red then increase slide postion to 100% slowly then press micro switch should blink green calibration should be complete.

Got a new slide valve sensor assembly in today. It looks like they changed it again.