indoor freezing

[airconadam]

hey fellas got called to a unit late yesterday indoor coil totally frozen up (fan coil unit in ceiling void) i put the indoor on fan only to get it to melt and went at it with my blow torch to get the thick of an hour later it was mostly off,also when i checked the outdoor unit the suction line was about 6 inch thick with ice all around the compressor and covering most of the outdor unit. Arrived back at site this morning not a bit of ice left i then put the system on cooling with gauges on and suction pressure went down to 0 bar so no gas and its got a leak somewere no problem BUT why does the indoor freeze up so badly when there is no gas or so little gas in the system is it because it has changed state much earlier than wot it should do????? think i have been thinking into it too much and no got myself confused thanks for your help

adam

[nike123]

hey fellas got called to a unit late yesterday indoor coil totally frozen up (fan coil unit in ceiling void) i put the indoor on fan only to get it to melt and went at it with my blow torch to get the thick of an hour later it was mostly off,also when i checked the outdoor unit the suction line was about 6 inch thick with ice all around the compressor and covering most of the outdor unit. Arrived back at site this morning not a bit of ice left i then put the system on cooling with gauges on and suction pressure went down to 0 bar so no gas and its got a leak somewere no problem BUT why does the indoor freeze up so badly when there is no gas or so little gas in the system is it because it has changed state much earlier than wot it should do????? think i have been thinking into it too much and no got myself confused thanks for your help

adam

0 bar suction pressure not necessary mean that there is no gas. It could be restriction in low side of circuit!
What is discharge temperature and presure and pressure when system is at stand by?

[Brian_UK]

As the suction pressure/temperature goes below the ambient dew point moisture and ice will form on the suction pipework.

As the coil starts to freeze up so there is less airflow across it and the temperature drops even further.

This process will continue until someone or something turns it off.