Controller pack
Service Manual
150
Safety and control device setting
SMGB0066 rev.0 - 12/2009
Zero reset Control
•
The purpose of this control is to correct the discrepancy of opening, if any, before a trouble occurs in the refrigerant cycle.
If first fully closes the expansion valve opening and then recovers to the predetermined opening.
Startup Control I (operation with fixed initial opening)
•
Selects the initial opening by determining between hot start or cold start from the state of discharge gas temperature (Td)
and outdoor air temperature (Ta) upon compressor startup.
Startup Control II (TdSH control operation)
•
This is a drive control to prioritize the closing operation in order to ensure the discharge super heat (TdSH) calculated From
discharge pressure (Pd) and discharge gas temperature (Td) after compressor startup.
normal control (TsSH control)
•
Controls the expansion valve opening to achieeve the target TsSH (SH set) by performig Pl calculation based on the inlet
gas super heat (TsSH) calculated by suction pressure (Ps) and inlet gas temperature (Ts).
Stop control
•
After compressor stop (real operation frequency = 0 Hz), retain for one three seconds the expansion valve opening
immediately before the stop, and then make the expansion valve opening “o” pulse.
Zero point control
•
This is a control to fully close the expansion valve opening during normal operation.
