Air and Water cooled inverter chillers and heat pump
D-EOMZC00105-17EN
Operation Manual
10/84
EWAD TZ - EWAD TZ B -EWWD VZ
Air and Water cooled inverter chillers and
heat pump
1.5 Available Controls
1.5.1
Evaporator pumps
The controller can regulate one or two evaporator pumps and takes care of automatic change-over between
pumps. It’s also possible to prioritize the pumps and temporarily disable one of the two. The controller is also
able to control the pump speeds if the pumps are equipped with inverters.
1.5.2
Condenser pumps (W/C units only)
The controller can regulate one or two condenser pumps and takes care of automatic change-over between
pumps. It’s also possible to prioritize the pumps and temporarily disable one of the two.
1.5.3
Compressors
The controller can regulate one or two compressors installed on one or two independent refrigerant circuit (one
compressor per circuit). All the safeties of each compressor will be managed by the controller. Embedded
inverter safeties are handled by the inverter onboard electronic and only notified to the UC
.
1.5.4
Expansion Valve
The controller can regulate an electronic expansion valve per each refrigerant circuit. Microtech® III embedded
logic will always guarantee the best operation for the refrigerant circuit.
1.5.5
Switchbox Pressurization fan for HFO units (W/C only)
In case of water cooled units which are i
nstalled in plant rooms it’s required to pressurize the switchbox to
avoid refrigerant accumulation that could lead to dangerous operations of the unit. To avoid this a
pressurization fan will maintain a constant air circulation inside the switchbox. This fan will be always running
when the internal temperature will exceed 23°C. Any drop in the delta pressure between the inside and the
ambient will generate a stop of the unit to re-establish a safe condition for the users.
1.6 Customer Terminal Block Connections
The contacts below are available at the user’s terminal block referred as MC24 or MC230 in the wiring diagram.
The following table summarizes
the connections at the user’s terminal block.
Description
Terminals
EWAD
TZ
Terminals
EWAD
TZ B
Terminals
EWWD
VZ
Notes
Evaporator Flow Switch (mandatory)
708, 724
708, 724
708, 724
24 Vdc digital input
Condenser Flow Switch
-
-
888, 890
24 Vdc digital input
Double setpoint
703, 728
703,728
703, 728
24 Vdc digital input
Current limit enable
884, 885
885, 891
-
24 Vdc digital input
External Fault
881,884
881, 884
542, 501
24 Vdc digital input
Rapid Restart Enable (optional)
764, 765
-
764, 765
24 Vdc digital input
Back-up chiller (optional)
764, 763
-
-
24 Vdc digital input
LOC/BMS selection (optional)
894, 895
881-1, 834
894, 895
24 Vdc digital input
On-Off Remote
540, 541
540, 541
703, 749
230 Vac digital input
Heat/Cool Remote
-
-
892, 893
Leak Detector Output
-
-
552, 553
General Alarm
525, 526
525, 526
525, 526
NO digital output (24…230 Vac ext supply)
Compressor #1 status
512, 513
512, 513
-
NO digital output (24…230 Vac ext supply)
Compressor #2 status
514, 515
514, 515
-
NO digital output (24…230 Vac ext supply)
Alarm Circuit #1 (optional)
560, 561
892, 896
564, 565
NO digital output
(24…230 Vac ext supply)
Alarm Circuit #2 (optional)
560, 562
894, 899
565, 566
NO digital output (24…230 Vac ext supply)
Evaporator Pump #1 start
806, 805
501, 530
527, 528
NO digital output (24 Vdc internal supply)
Evaporator Pump #2 start
806, 807
501, 531
559, 560
NO digital output (24 Vdc internal supply)
Condenser Pump #1 start
-
-
550, 551
NO digital output (24 Vdc internal supply)
Condenser Pump #2 start
-
-
559, 562
NO digital output (24 Vdc internal supply)
Demand Limit
888, 889
888, 889
887, 889
4-20 mA analog input
Current Limit (optional)
886, 890
887, 886
-
4-20 mA analog input
Setpoint Override
886, 887
890, 886
886, 887
4-20 mA analog input
Pump VFD Signal (optional)
882, 883
-
-
