Carlyle 06D unloaders not working
I found this problem on a transport system that was icing the evap coil.
Here's the system: Carlyle 06D 208vac, 6 cylinders, with pressure (non-electric) suction cutoff unloaders on 2 of the cylinder heads. R22 with a dual coil evap - 2 solinoid valves, 2 TXVs. A fairly simple system.
In full cooling mode, both TXVs working, get normal operation, no problems.
But in reduced cooling mode, one TXV working, get icing on the evaporator. The suction pressure goes down to 32 -35 psi. At this low pressure, the two cylinder heads should have unloaded. But they don't unload, because I check the current draw, and it's 27A, which is a fully loaded value.
Next step: I change both unloaders (but not the cylinder heads) and adjust, but I get the same result. When I changed the unloader, I checked the unloader valve body (located in the cylinder head) and it seems to move normally under spring pressure.
I can't figure out why neither cylinder head will unload. This compressor is a recent rebuild, so something may have gone wrong during the rebuild.
unloader gaskets installed properly? they go on many ways, but only work in one
Originally Posted by tjc76
That's interesting. I'll have to look into that. When I changed the unloaders the gaskets remained stuck to the cylinder head, so that's how I left them. They are odd looking with 3 holes for the mounting screws and a bunch of cut-outs.
Good tip, thanks.
Like said above, gaskets or maybe strainer on bleed port clogged?
I checked the gaskets today, and they are in the right postion. All ports appear clean.
We replaced the compressor, and the system works good. So the problem is with the compressor. Still can't figure out why both unloaders were not working.
The compressor was a recent rebuild by an outside vendor. We contacted the rebuilder for advice, but all we got was flak.
Have mentioned this on other posts concerning Carlyle compressor rebuilds. Use the oem for your source such as Carrier. It costs twice as much but I've been burned getting a number of 06D's from the low bid vendor. From oil sight glass leaks to rusted heads, bad gaskets, wrong end bells, you name it. Once I started ordering from Carrier, those problems all went away.
10-4 on that.
Originally Posted by big johnson
Our carrier office has been offering both.The good stuff and a cheaper one.But we,re too afraid to try the cheaper rebuilds.
I did a little research and found that this compressor had the same failure before and after the rebuild. The rebuild company is not oem. I work for a public agency, and they always go for the lowest bidder.
Our invoice shows $1100 for the rebuild price. I don't know if this is considered high or low for a 06D rebuild.
Check the valves. If you loose one reed on the three at each cylinder you compressor will vibrate to hell.....but if you loose another one on another head....you will not notice a difference and the unloaders will not function properly.
To assure the unloaders are running properly, close down the suction and wait for the pressure to drop slowly. They are mechanical unloaders so make sure they are set properly.
The world is moved along, not only by the mighty shoves of its heroes, but also by the aggregate of the tiny pushes of each honest worker.