AzRob
17-09-2007, 05:03 PM
46 foot freezer trailer modified to be stationary with condensing unit on the ground under the trailer. System has two evaps, one 4 fan and one 3 fan unit. I noticed box temps dont get below 25f degrees in the heat of the day (runs 24-29) and early morning hours has box temp of 20f degrees.
System was designed by a local Refrigeration outfit here in Arizona, has been frzing product to -5 in the past, apparently designed for that box temp.
Quick look at the system, I observed the following:
1. 408a - suction of 25 psi, discharge of 225. Ambient 100 degrees, box temp 27
2. One evap with no evidence of draining except early morning hours and not much at that. (puddle on the ground minor and only evident in early morn hrs, other evap..plenty of water during defrost) Good air flow through both evaps, one not draining not frozen up.
3. Seems to be one LLS supplying both evaps, noticed no other special controls persay.
4. Bubbles in sight glass.
5. Door (roll up) seal at top shows light all the way across.
6. 5HP compressor
7. Defrost 4x per day, dont know duration.
8. suction line slight sweating at condensing unit, liquid line warm @ condensing unit.
9. Unit runs constantly except at defrost. Stat set to -5.
Im wondering a few things:
1. How does dual evaps play on the gauge readings? If one evap is having problems, do the gauges show an "average" between the two?
2. What evap temps would be expected for a box that sits in the hot sun all day? How to determine apprx gauge readings for this system.
Im leaning toward evap prob...the one thats not condensating. Think Im headed in right direction? Tad different system than 4-5 ton residential A/C's with fixed orfice!
System was designed by a local Refrigeration outfit here in Arizona, has been frzing product to -5 in the past, apparently designed for that box temp.
Quick look at the system, I observed the following:
1. 408a - suction of 25 psi, discharge of 225. Ambient 100 degrees, box temp 27
2. One evap with no evidence of draining except early morning hours and not much at that. (puddle on the ground minor and only evident in early morn hrs, other evap..plenty of water during defrost) Good air flow through both evaps, one not draining not frozen up.
3. Seems to be one LLS supplying both evaps, noticed no other special controls persay.
4. Bubbles in sight glass.
5. Door (roll up) seal at top shows light all the way across.
6. 5HP compressor
7. Defrost 4x per day, dont know duration.
8. suction line slight sweating at condensing unit, liquid line warm @ condensing unit.
9. Unit runs constantly except at defrost. Stat set to -5.
Im wondering a few things:
1. How does dual evaps play on the gauge readings? If one evap is having problems, do the gauges show an "average" between the two?
2. What evap temps would be expected for a box that sits in the hot sun all day? How to determine apprx gauge readings for this system.
Im leaning toward evap prob...the one thats not condensating. Think Im headed in right direction? Tad different system than 4-5 ton residential A/C's with fixed orfice!