background image

D-EOMCP00104-14_01EN 

 

Operating Manual 

 

22/35 

 

EWYD_BZ 

 

recovery circuit operation, the related compressor will trip and the alarm reset will not be allowed up to the flow is recovered 
(otherwise recover heat exchanger freeze will occur). 

5.20.2 

Recovery control 

When heat recovery is activated the control will activate or deactivate recovery circuits with a step logic.   In particular a 
next  heat  recovery  stage  is    activated  (a  new  heat  recovery  circuit  is    inserted)  if  the  heat  recovery  leaving  water 
temperature remains below the setpoint by an amount greater than an adjustable regulation band for a timer greater than 
an adjustable value (heat recovery interstage). When a recovery stage is requested, the relative compressor is completely 
downloaded and then the recovery valve is energized. After recovery valve switches the compressor load is inhibited until 
the saturated condensing temperature is lower than an adjustable threshold (default is 30.0°C). 
 
At the same manner a heat recovery stage is  deactivated (a heat recovery circuit is  removed) if the heat recovery leaving 
water temperature remains above the setpoint by an amount greater than an adjustable dead regulation  band for a timer 
greater than the previous defined value. An high temperature  setpoint is  active in the  recovery loop; it will disable all 
recovery  circuits  at  the  same  time if  the  heat  recovery  water  temperature  rises  above  an  adjustable  threshold  (def ault 
50.0°C). A three-way valve is  used to increase recovery water temperature at startup; a proportional control is  used to 
establish valve position; at low temperature the valve will recirculate recovery water, while at temperature increasing the 
valve will bypass a portion of the flow. 
 

 

5.20.3 

Compressor limiting 

Two levels of limits are  included in the control: 
 

 

Load inhibit. 

The load is not allowed; another compressor may start or may be loaded.  

 

Forced unload. 

The compressor is unloaded; another compressor may start or may be loaded  

 
The parameters that may limit compressors are : 

 

 

Suction pressure 

The compressor load is inhibited if the suction pressure is lower than a “stage -hold” setpoint 

The 

compressor is unloaded if the suction pressure is lower than a “stage-down” setpoint 

 

Discharge pressure 

The compressor load is inhibited if the discharge pressure is higher than a “stage-hold” setpoint 

The compressor is unloaded if the discharge pressure i

s higher than a “stage-down” setpoint 

 

Evaporator outlet temperature 

The compressor is unloaded if the evaporator outlet temperature is lower than a “stage -down” setpoint 

 

Discharge Superheat 

The compressor load is inhibited if, the discharge superheat is below an adjustable threshold (default 1.0°C) 
for an adjustable time (default 30s) from the compressor starts at the end of prepurge procedure.   

Summary of Contents for EWYD-BZ

Page 1: ...parteinvert Air Cooled chiller heat pump with screw compressors EWYD_BZ REV 01 Date November 2020 Supersedes D EOMCP00104 14EN Operating Manual D EOMCP00104 14_01EN...

Page 2: ...n 19 5 8 Compressors startup procedure 19 5 9 Fan pre starting in heating mode 19 5 10 Prepurge procedure with electronic expansion 19 5 11 Prepurge procedure with thermostatic expansion 19 5 12 Oil h...

Page 3: ...n heating mode 26 5 24 Other functions 26 5 24 1 Hot Chilled Water Start 26 5 24 2 Fan Silent Mode 26 5 25 Unit and compressors status 26 5 26 Start up sequence 28 5 26 1 Unit start up and shut down f...

Page 4: ...it Do not service or operate on the unit without having switched off the main switch 1 2 Before switching the unit Before switching on the unit read the following recommendations When all the operatio...

Page 5: ...r Cooled CP Condensing Pressure CSRT Condensing Saturated Refrigerant Temperature DSH Discharge Superheat DT Discharge Temperature E M Energy Meter Module EEWT Evaporator Entering Water Temperature EL...

Page 6: ...pCOe Water pump control N pCOe EXP 4 pCOe Additional fan steps for compressors 1 2 or for compressors 3 N EEXV driver 1 EVD Evolution Electronic expansion valve control for compressor 1 Y EEXV driver...

Page 7: ...Operating Manual D EOMCP00104 14_01EN EWYD_BZ 7 35 3 2 Main components Unit controller EVD Evolution Electronic Expansion Valves controller...

Page 8: ...3 3 Components operating limits Component Temperature C r H non condensing pCO5 built in display 20 60 90 pCO5 40 70 90 EVD Evolution N A 90 pCOe 10 60 90 EVD Evolution Electronic Expansion Valves co...

Page 9: ...ettings submenu Down Maint submenu Built In PGD navigation Entering any other section different menus or mask loops are shown From every loop with or key it is possible to access the father menu and s...

Page 10: ...beginning from the main menu is shown Masks loops of the same group of parameters can be accessed using left and right arrows creating also horizontal loops Parameters within a same horizontal loop co...

Page 11: ...Pressure bar psi Temperature C F Time sec sec As far as pressure is concerning the interface shows if shown data are gauge or absolute using the postfix g or a respectively 4 3 Default passwords Sever...

Page 12: ...is set to 3 C 37 4 F adjustable by the operator in the range freeze alarm setpoint 1 3 C freeze alarm setpoint 1 8 F 37 4 F Cooling Glyco When this mode is selected the control will operate to cool t...

Page 13: ...tpoint reset methods are available to modify the local or double setpoint None local or double setpoint are used on the base of the double setpoint digital input This is called base setpoint 4 20mA ba...

Page 14: ...pressor remains in Automatic and must be re switched to Manual by the operator if required Compressors in manual mode are automatically switched in automatic mode at their shutdown The compressor load...

Page 15: ...f the last compressor is allowed only if the absolute value of the difference between the measured temperature and the setpoint exceeds a Shutdown T value A FILO First In Last Off logic is adopted The...

Page 16: ...tion Band Max 0 Max PD controller proportional action 5 5 2 Manual Control The control will apply a fixed duration pulse the magnitude is the pulse duration set in the automatic control for each manua...

Page 17: ...ixed at 75 Unload up to 50 Start Off 12b SetP RDT T or T SetP RDT Fixed at 75 Fixed at 75 Start Off 13 Fixed at 75 Fixed at 75 or 50 Load up to 50 Off 14 if lag1 at 50 Fixed at 75 Load up to 75 Fixed...

Page 18: ...b SetP RDT T or T SetP RDT Fixed at 75 Fixed at 75 Fixed at 10 if lag2 at 75 Fixed at 75 Fixed at 75 Fixed at 11 Fixed at 75 Unload up to 50 Fixed at 50 12 Fixed at 75 Fixed at 50 Fixed at 25 13 If T...

Page 19: ...ed and its loading will not be enabled up to the pressure ratio exceeds a set value default equal to 2 5 8 Compressors startup procedure Before to start compressors the unloading solenoid valve is ene...

Page 20: ...is reached a Low Ambient Start Up low pressure alarm is issued At the end of the low OAT start the evaporator pressure is checked If the pressure is greater than or equal to the evaporator pressure s...

Page 21: ...eat Defrost procedure will never be executed if Ta 7 C adjustable under maintenance password Defrost procedure will never be executed if Ts 0 C adjustable under maintenance password During defrost the...

Page 22: ...very loop it will disable all recovery circuits at the same time if the heat recovery water temperature rises above an adjustable threshold default 50 0 C A three way valve is used to increase recover...

Page 23: ...o pumps are selected the system will automatically start the pump with lower operating hours each time a pump has to be started A fixed starting sequence may be set A pump is started when the unit is...

Page 24: ...e value 25 sec At the same manner a stage down is executed the previous stage is activated if the pressure ratio falls below the target setpoint by an amount equal to a stage down dead band depending...

Page 25: ...when condensing temperature is within the deadband or a new stage is activated Each fan stage will have its own adjustable stage up default 0 2 and stage down default 0 2 deadband 5 23 1 2 3 Control o...

Page 26: ...e of 10 0 C 50 0F If the condensation control is either speedtroll or fantroll each step is activated after a fixed delay of 6 seconds The control is released to automatic control if the outside ambie...

Page 27: ...off 3 Off Ready 4 Off Ready 5 Off Ready 6 Off Ready 7 Off Switch Compressor is off from switch 8 Auto Automatic compressor load management 9 Manual Manual compressor load management 10 Oil Heating Co...

Page 28: ...requires unit unloading New Compressor start required see loading table Yes No New Compressors selection Compressors loading Compressors standby Compressor line contactor closing Transition confirmati...

Page 29: ...Operating Manual D EOMCP00104 14_01EN EWYD_BZ 29 35 Unit Stop Compressors shutdown procedure Evap flow switch open within timer expiration Yes Unit Trip No Unit Off...

Page 30: ...rt No HR Trip Yes HR temperature control stabilitation HR circuits activation enabled Control requires loading Control requires standby Control requires unloading Loading interstage timer expired PID...

Page 31: ...Operating Manual D EOMCP00104 14_01EN EWYD_BZ 31 35 Heat Recovery Stop Circuits deactivation procedure Evap flow switch open within timer expiration Haet Recovery Off No HR Trip Yes 3Way valve opening...

Page 32: ...ressors trip Compressor trips are caused by Mechanical High pressure A High pressure switch alarm will trip the compressor as soon as the high pressure switch opens A manual reset of the alarm is requ...

Page 33: ...than 10 seconds from compressor start A manual reset of the alarm are required to restart the unit Compressor overload or motor protection A Compressor overload alarm will trip the compressor if the...

Page 34: ...e alarm on circuit 1 27 Expansion Error Expansion boards error 28 29 EXV Driver Alarm 1 EXV Driver 1 Alarm 30 EXV Driver Alarm 2 EXV Driver 2 Alarm 31 Restart after PW Loss Restart after power loss 32...

Page 35: ...cular purpose of its content and the products and services presented therein Specification are subject to change without prior notice Refer to the data communicated at the time of the order Daikin App...

Reviews: