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I noticed this with R422d I think it has a 13 degree glide.

Takes some getting used to, but you'll get it.

Originally Posted by Greend88

lol yeah it took me awhile to get my previous co workers to understand temp glide. They have several 407c wall mount/pressurization units on some power houses in a refinery and they thought they could use R-22 PT Chart on there gauges for it.

Good thing my ak900s pointed this out to me or I would've undercharged the unit. It was cooling well when i left 18* drop with a TXV mismatched indoor/outdoor.

lol yeah it took me awhile to get my previous co workers to understand temp glide. They have several 407c wall mount/pressurization units on some power houses in a refinery and they thought they could use R-22 PT Chart on there gauges for it.

I just read all about it, thanks for the clarification. I've never worked with any refers that were that different between the dew, bubble, saturated temps. It just threw me for a loop when they were different on the guages. I understand it much better now. Gonna take some getting used to dialing in a charge.

That's the thing with temp glide. Its gonna be different for your low side and high side at the same pressure. Bubble Point on high side and Dew Point on low side.

A little info for you http://www.refrigerants.com/pt_chart.aspx

Originally Posted by jtrammel

Why is it like that, I don't care what the glide is 0 psig and 0 psig should be the same saturated temp??? Not that I don't care what the glide is, in just sayin the temps should be the same at a given pressure.

Some charts you are used to seeing will divide dew and bubble points into
a single line and cross over at some point.
At one pressure there is a dew and bubble point with blends.

The gauges use dew point and bubble point.

Nope

Originally Posted by itsiceman

My 1250 is showing about 10 at 0 and moves closer like 6 over 100

Why is it like that, I don't care what the glide is 0 psig and 0 psig should be the same saturated temp??? Not that I don't care what the glide is, in just sayin the temps should be the same at a given pressure.

My 1250 is showing about 10 at 0 and moves closer like 6 over 100

Does look like a ten degree glide: http://www.certifiedrefrigerant.com/...rt%20r421a.pdf

Are the compressors your using POE? Retrofit sheets say that it's compatible with Mineral Oil. But it's a mixture of 58.0% R125 and 42.0% R134a which are both not miscible with Mineral Oil: http://www.certifiedrefrigerant.com/...rt%20r421a.pdf

Food for thought...

At 0psig on high and low the sat temp reading was 10* different on the ak900s. We've used it a few times and its worked well so far.

Must be the glide.

I tried to find the "temperature glide" for the blend and couldn't find it.
I did read they are putting a lubricant in the can ....... Yikes

AK900 pt conversion 421a

I'm charging a dry 22 unit with 421a and noticed the pt conversion on my ak900 for 421a is 10* different between the high and low. Can somebody check their 421a setting to see if its just mine or is it just loaded to the guage wrong.