love to fish
04-07-2005, 09:07 PM
hey techies as posted earlier we are overhauling/converting a cvhe112 L91 vintage. this chiller has had 2 operating problems .1st problem is oil loss during extended very low load operation causing oil failure trip out ,the oil bearing seal met specs at .0025 clearance and no sign of oil loss at seal. The mechanics on site {another company} said the tower water flucuates between 76-85 on a two speed tower fan and condenser by-pass valve. 2nd problem when chiller starts it ocasionally trips the oil pressure switch when the vent line soleniod opens after time out due to foaming of oil in sump,vent line is 1 1/8. this usually happens during a high load start up. we are changing the charge from 2390 lbs of r-11 to 1800lbs r-123. will the refrigerant operating level in the evaporator remain the same during low loads? we are looking to weld in a nipple for eductor but want it at the best level for unloaded operation, can not find the level bench mark at evap tube sheet and we are thinking of a level at the top of the top row of tubes, the 2nd eductor goes to the 1st stage cover at bottom. we are thinking of changing the eductor line from evap to 3/8 from 1/4 for better oil return, installing by pass around vent and throttling it or changing the ventline solenoid to the style with the stem in the bottom to lift diaphram sorry to be so long winded and any help would be greatly appreciated