1. Checking the system data

Preferably via remote diagnosis (Remote Access), BITZER Digital Network or BEST SOFTWARE

• Check adjusted set point for evaporation temperature control.
• Check if pump down operation is activated in the control, and if yes, to what set point it is adjusted.
• Check minimum and maximum evaporation temperature during operation.
• Check operation of the capacity controlled CRII compressor for frequent starts and stops (cycling rate). Note that frequent starts and stops often occur at night or outside business hours.
• Cycling rates > 120 per day are suspicious.
• Cycling rates > 160 per Tag are very suspicious.
• Evaporation temperature variations > +/- 5 K are suspicious.
• Evaporation temperature variations > +/- 10 K are very suspicious.
• ⇨ High cycling rates in combination with high evaporation temperature variations and frequent pump down operation indicate a malfunction of the CRII systems's capacity control function.

If the system shows the anomalies mentioned above, it should be checked on site!

• On site, the system's refrigerant charge, temperatures and pressures should be checked.
• Are the temperature and pressure values plausible? Is the refrigerant charge correct?
  If both can be answered with "yes", the CRII solenoid valves at the compressor must be checked.

The procedure described above assumes that the system layout meets the actual requirements and that all cabinets and cold rooms are in operation.