2M startup

[Ray D]

" I started up my new system Saturday. I have a couple of issues. The first one was that I didn't have any power to the Carel thermostat. I checked and verified voltage at the terminal strip. I could see the ground path, but no path for 12V+ to compressor module +. I pulled the t'stat lead off the compressor power module and put a jumper on it to power it up. I was able to get the t'stat programmed, but no system start. I finally pulled the compressor lead off the strip and moved it to terminal 5 to get some power and reconnected the t'stat to compressor module +. The system fired up, but the cooling pump did not. Same problem, I had a ground, but no 12V+. I disconnected the pump 12V+ lead and put a jumper on it to get it running. I got the system charged and it seemed to be doing a good job of cooling the box down. I was in and out of the boat monitoring the box and the pressures. It was running about 10 psi on the low side and about 90 on the high side. After 2 1/2-3 hours, I came out to check pressures and found the high side going through the roof (about 265psi). The cooling pump had quit. I shut the unit down and started troubleshooting the pump. The motor resistance changes every time you shake the pump, from 0 ohms to 300. So the pump is dead. I was wondering why the high pressure switch didn't shut the unit down. One side of the switch goes to terminal 1 on the strip, nothing else connects to it. The other side goes to terminal 85 on the relay. How does the switch work? Any ideas on the power problem?"

[Forum Tech]

"Ray,It may be helpful for you to review the instructions for the Carel retrofit kit. The Carel terminals one and two connect to the condensing unit terminals seven and eight. The Carel terminals four and five connect to the condensing unit terminals nine and eleven.Let me know if this solves the problem.Forum Tech"

[Ray D]

The manual I have is version 2.0-January 2010.Page 9 step 1 says to connect the Carel (-) to the power module large - spade terminal connection.Page 10 step 2 says to connect the red wire from the t'stat to the power module large (+) spade connection.Both of those connect with a double male-female adapter.Do I have the wrong manual?

[Ray D]

The pics show them there too.My manual is part number 011-1020 Carel Retrofit

[Ray D]

"Also, my book shows the Carel terminals 1&2 connecting to the Danfoss power module terminals C&T.This has got to be the wrong book."

[Ray D]

I went to the boat and rewired as you instructed. I started the unit up for a few seconds and had power at the pump leads. So- it looks like the problem is solved. Can you email me the correct manual so I can add it to my boat manuals?

[Ray D]

"I installed the replacement pump and got the system running again. After about 6-7 hours, the low side was down to 4 psi, high side about 90. Carel probe is on the side of the cold plate. The thermostat was showing 0.8 degrees. The unit shut down. I went to check it, the high side was dropping through 160 psi. The unit restarted at 150 psi, climbed to 200 and shut down. It repeated this 3 times, and I shut it down. It was almost as if the expansion valve just shut off. The sensing bulb is right next to the exit from the holding plate about 1" away from the plate at the 2 o'clock position, and the line and bulb are insulated. I have a 90 degree connector on the inlet of the holding plate, a 1" stub of tubing and the expansion valve. What should I look for at this point?"

[Forum Tech]

"Ray,A blocked TXV won't cause high pressure, it would cause very low suction pressures. It sounds like the condenser isn't getting enough water flow through it. Can you check the amount of flow coming out of the condenser, either at the condenser, or at the overboard discharge? Is the inlet strainer clear of debris, and is there enough water getting to the pump? I have found these pumps to be extremely reliable, I doubt that there is a problem with the pump, more likely to be another source of restriction in the water circuit.How much refrigerant is in the system?Do you know what the high side pressure was earlier, like perhaps the first hour?Forum Tech"

[Ray D]

"I have done several things since last post. Your question about refrigerant quantity was right on. I had been unable to get a scale in this little town and charged it by pressures and the sight glass. It was slightly overcharged. I went out of town and got a scale, bled it down, pulled vacuum, and recharged it with the scale. I pulled and checked the seawater strainer, it looked OK, but since it was out, cleaned it. Water flow appears OK- Condensor is never warm to the touch. I had the system running yesterday. It pulled down to -10 and shut down. It took 3 hours to pull down from 0 to -10. While it was down, I backed out the superheat 1/4 turn. It was down for 16 minutes and restarted at 0 degrees. Second pull down took 2 hrs, 41 minutes. While down, I backed out the superheat 1/4 turn. Unit was down 10 minutes. Suction line starting to sweat very slightly. Line temp was 82 degrees. Third pull down took 1 hr, 45 minutes. Unit was down for 14 minutes. Restart at 0, monitoring suction line temp closely. I had a bucket of water ready with a rag in it to warm the suction line if needed. Here are the figures from last pulldown yesterday.Time Amps Temp Suction Discharge Line temp5:42 startup5:56 -1.0 No data- phone rang6:05 6.6 -2.5 1 107 line frosting- warmed line and closed superheat 1/4 turn.6:06 6.5 -3.0 1 105 54.16:11 6.7 -4.0 0 106 70.56:15 6.6 -5.0 0 107 75.36:21 6.8 -6.0 0 107 71.56:30 7.0 -7.0 -1 105 786:39 7.2 -8.0 -1 105 80.96:51 7.1 -9.0 -2 107 81.77:12 shutdownI later found that my amp data is skewed .6 amp. The stereo was on, so that needs to be deducted from the above figures. I may can try opening the superheat a little more- what are your thoughts on that? I am also wondering about the short downtime. Do I maybe have a refrigerator plate? Ambient temp got up to 86, in the cabin it was 90.It's a big box- 12 cubic feet. 1/3 is the freezer, there is a 2" foam spillover into the refrigerator. The fridge temp looks good, about 36 degrees in the middle. The suction line temp was monitored with a digital refrigeration thermometer. I put a ~3" piece of insulation on the suction line about 6" upstream from the service valve and inserted the thermometer in next to the tubing. It's getting very close, but the short downtime has me a little worried..."

[Ray D]

"I ran a test to find the melting temp of the plate solution today. The solution is mixed to work between 0 and 10 degrees, not 0 and -10 like I thought. So that question is answered."