I need some direction to figure this out, I would appreciate any help.
I have been working on a 410A system for a couple of days. When I first arrived the customer's supply evaporator box was convered underneath with ice bubbles. The air was flowing through the furnace cavity normally and checked the filters for the return. One definite problem was stuck contractor at outside coil. I soon replaced that and begun to check the charge on the system. The outside ambient was around 97, the gauge was reading may be around 40 deg F (100 psig), before system started. When system was started, I began noticing the the all indicators was out of range high superheat 40's high supercool 40~50's. I ran the fan for a couple of hours to try to melt the ice. I could hear the drain pump working hard to pump out the water to outside.
5 hours later I charged the unit about 2 pounds of refrigerant. The total superheat was around 18 degrees and evap temp at around 34 degrees, but did notice within 5~7 minutes the high side pressure kept climbing past 550 PSIG. I decided to quit, and comeback a couple days later to make sure all the ice has been melted.
When I went back this afternoon, I measured the 78 degree on both (230 PSIG) before I started the system. The low side stayed at 34deg with 18 deg super heat, but high side gradually went up but not fast as before. The subcool was around 50 deg but after about 20 minutes the high pressure started climb beyond 550 PSIG; it started around 400's when system started.
I can't figure out whether this is restriction or simply low on charge. I am thinking about recovering refrigerant and see how much was actually in there, and do pressure test if I have to.
I would appreciate if someone can guide me some direction on this.
Thank you.
I have been working on a 410A system for a couple of days. When I first arrived the customer's supply evaporator box was convered underneath with ice bubbles. The air was flowing through the furnace cavity normally and checked the filters for the return. One definite problem was stuck contractor at outside coil. I soon replaced that and begun to check the charge on the system. The outside ambient was around 97, the gauge was reading may be around 40 deg F (100 psig), before system started. When system was started, I began noticing the the all indicators was out of range high superheat 40's high supercool 40~50's. I ran the fan for a couple of hours to try to melt the ice. I could hear the drain pump working hard to pump out the water to outside.
5 hours later I charged the unit about 2 pounds of refrigerant. The total superheat was around 18 degrees and evap temp at around 34 degrees, but did notice within 5~7 minutes the high side pressure kept climbing past 550 PSIG. I decided to quit, and comeback a couple days later to make sure all the ice has been melted.
When I went back this afternoon, I measured the 78 degree on both (230 PSIG) before I started the system. The low side stayed at 34deg with 18 deg super heat, but high side gradually went up but not fast as before. The subcool was around 50 deg but after about 20 minutes the high pressure started climb beyond 550 PSIG; it started around 400's when system started.
I can't figure out whether this is restriction or simply low on charge. I am thinking about recovering refrigerant and see how much was actually in there, and do pressure test if I have to.
I would appreciate if someone can guide me some direction on this.
Thank you.
source https://hvac-talk.com/vbb/showthread.php?2222769-High-Pressure-Gradually-climbing-to-over-550-PSIG&goto=newpost
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