What is this?

[MAC AIR]

This pic is from a heatcraft condenser for walk in freezer. If you look at the pic there is a valve off the side of compressor. I have never seen this before wondering what it is exactly. This is a copeland scroll compressor. I know the pic quality is not that good sorry~!

[KB Cool]

Liquid injection!!! Liitle sensing bulb in top of compressor well opens valve to feed liquid into low side to lower discharge temp. Kind of like a TXV.

[Dchappa21]

Not sure of the official name... But I like to call it a liquid injection valve.
It's used to cool the compressor, the valve will meter liquid into the compressor to cool it. I believe the little tube going to the dome of the compressor is what tells the valve that the compressor is to hot.

[KB Cool]

DTC is the official name. Does that one have a current sensing relay. So if the compressor overheats and quits running the supply of liquid to the valve is cut off. My co worker replaced one of these compressors and it lasted a day. My guess is the DTC flooded it out and broke the scroll. I changed the second at it's still working. The instructions said to bleed valve before start up. I did, he didn't!!!

[Dchappa21]

Most of the heatcraps I've seen don't have the current sensing relay.... So if it ever trips the overload, it will just sit there fillin it full of liquid..

[KB Cool]

Most of the heatcraps I've seen don't have the current sensing relay.... So if it ever trips the overload, it will just sit there fillin it full of liquid..

The new valves don't need the solenoid. I wonder why?

[Dchappa21]

The new valves don't need the solenoid. I wonder why?

The current relay is only required if the charge is more than 10 pounds... According to copeland. Which is only every one I've seen. Lol

[MAC AIR]

I am not sure if there is a current relay on this unit. I was at the call because customer complained of frost build up on the product. This walk in freezer is in a wherehouse that right now is usually 90 degrees or more and when they get a load they have the door open and I think that is where the frost is coming from . There is also 1 of 6 evap fans out. Which I am going to replace. The freezer was to packed with product to the job, but before I left I took a peek at the condenser and noticed the compressor was a little noisy (valves). and I saw what I now know is called the dtc liquid injector. Thanks to all of your guys help . Thank you. Now it has me thinking that could there be some thing wrong with the dtc. And is that why the noisy compressor? How can you tell if the dtc is working correctly? Thanks for all the help!

[crackertech]

http://www2.renkulde.no/MKDokume.nsf...60204_1201.pdf

[MAC AIR]

Thank you cracker...very nice info...and thats kinda what I thought ...if this compressor takes a dump replace both,compressor and dtc.

[KB Cool]

I guess they have a cap tube style that requires a soleniod and the new DTC valve which does not! Why are they using these scrolls anyways. Are they cheaper to the equipment manufacturer. But, cost more $$$$ to the end user when it goes out versus a pump w/ valves?

[craig1]

Why are they using these scrolls anyways. Are they cheaper to the equipment manufacturer. But, cost more $$$$ to the end user when it goes out versus a pump w/ valves?

They are more efficient than a hermetic and more durable too. Some of them are VERY adaptable and can do low and med temp 404a, 134a, and even 22 (thanks to the demand cooling)

[KB Cool]

They are more efficient than a hermetic and more durable too. Some of them are VERY adaptable and can do low and med temp 404a, 134a, and even 22 (thanks to the demand cooling)

More effecient? Yeah, but more durable? I don't know about that. Maybe if all the other components are working. But, heaven forbid the pumpdown switch(low pressure) fails to open!!!: