Head skyrockets and low drops...IN SECS!

[Tommy1010]

On start up, head pressure sky rockets past 450 in secs, and low side drops below 10 at the same speed. On shut off , they take forever to equalize...actually i didnt stay there long enough to see if it even would.

Wheres the most likely plug? Txv system , carrier water cooled 10 ton package unit r22.

[marvin]

i think you hit it with the txv or plugged screen but also sounds like it could
be over charged with the head going up like that.

[John Culpepper]

Does it have a solinoid valve in the liquid line?

[Tommy1010]

Found it. Stuck close TXV. Noticed no cold at outlet. I counted turns one way and when i hit about 4 full turns, I heard it screamin through and got cold, and equalized the system right away.

[coolerinfrederick]

i've never seen a stuck txv cause the head to go up like that, was it overcharged ?

[Tommy1010]

i've never seen a stuck txv cause the head to go up like that, was it overcharged ?

I just got back into the plant 10 min ago.

No i cant be overcharged. I mean I didnt pull the charge, and the system has been runnin AS IS for 3 yrs. Meaning, no opening up of system.

I think its IN FACT UNDERCHARGED...baby leak from shraeder valve when I took cap off....Maybe just slightly....but definatley NOT OVER.

I'll get some readings and temps and get back in a few. Hope you all keep up wit me on this.

[Tommy1010]

i've never seen a stuck txv cause the head to go up like that, was it overcharged ?

I also heard that due to the fact that its water cooled..makin it more efficient...gives it less condenser room, gives it less time and room to stack up in the high side........

Does this contribute? and how? if so or not?

[coolerinfrederick]

oh yeah ur right the water cooled condensers are much smaller and hold alot less refrigerant, causing the refrierant to stack up into the discharge side and contributes to the high press.