Deleted smard 656 air dryer

[paul441]

Hi Guys
looking for some advice on a deltec smard 656 air dryer,I normally work on air compresseors but have now got my f-gas to work on the dryers finding them a pain if I'm honest.this unit is showing high dp and temp on the controller fan coming in coil clean etc,has hgbv on I think when adjusting it can hear gas but comp and suction started to frost over and then trip out on low evap temp, have adjusted back ,when gauges on LP was 5bar hp was 19 bar it's r404a and it holds 12kg could it be short on gas sight glass not showing bubbles , not sure what else to look for and can't get any numbers for technical help with this make deltec. Would welcome any advice.

Thanks Sorry that's a deltec smard 656 air dryer

[dorinspeedy]

You must check: fan and airflow on condenser, what temperature is compressed air entering in dryer, on r404a you must have a pressure on suction aprox. 6 bar, only test dryer loaded (in instalation), what type of control condenser fan have? Check your e-mail.

[glenn1340]

If it trips on low pressure when you adjust the HGv you`ve gone to far. The purpose of the hot gas valve is to keep the evaporator pressure steady as the txv can`t react quickly enough to cope with rapidly changing compressed air inlet temp (compressors on/off load) as dorin states keep it around 6 bar. As we`re in the summer what`s the ambient temp onto the condenser? many a time I`ve been into a plant room where the temperature is unbearable. As regards the bubbles in the sight glass, when the fan stops you should get a flow off bubbles in it. If not, it COULD be an indication that it`s low on gas, that`s not always the case though just a pointer in that direction. You`ll need to check the sub cooling too. Check out the surrounding conditions and simple stuff, before you start adjusting controls etc.

[paul441]

Thank you for your advice glen and DorianDorian

[dorinspeedy]

Imagine as I am in Romania in a small town, repairing or maintenancing this units is a challenge, Atlas Copco,here ask for payment affront for spare parts and for one hour of their work almost 50EU, and almost no documenation to find, but we work somehow, help from internet, forums, friends.... I'm only a maintenance tech on a shoes factory and I have many machines to attend and mainteance them as cnc cutting machines and others.