WaterFurnace Envision2 NXW Chiller - Manual (Page 19)

19
ENVISION 2 NXW REVERSIBLE CHILLER INSTALLATION MANUAL
TB Typical AquaStat
24VAC
24V COM
Comp 1
Comp 2
Rev Valve
Acc 2
Acc 1
Alarm
Circuit 1 Alarm
Circuit 2 Alarm
24VAC
24V COM
Comp 1
Comp 2
Rev Valve
Accessory Item 1
R
C
Y1
Y2
O/B
X2
X1
L
LC1
LC2
R
C
Y1
Y2
B
NOTES:
1) Acc Output 1 is cycled with the lead compressor
2) Acc Output 2 is cycled with the lag compressor
Unit Power Supply
208-230/60/3,
460/60/3, or 575/60/3
G L3 L1 L2
PB
Black
Red
White
Black
White
Red
Field Wiring and Control Setup
High Voltage Connections
Low Voltage Connections
Line Voltage
Power supply wiring connects directly to lugs on the topo
of the electrical disconnect. In 208-230V applications, heat
pumps are factory wired for 208V supply. In the case of
230V supply, the blue and red wires from the primary of the
transformer will need to be swapped.
Low Voltage Operation
Thermostat/Controller (Aquastat)
A two-stage 24VAC aquastat or liquid controller (field
supplied) must be used to turn the reversible chiller on/off, and
to switch modes for heating/cooling. Multiple chillers in the
same bank must be controlled from one aquastat/controller
(must be isolation relays for multiple unit applications).
Low Voltage Connections
Connect low voltage wiring as shown in Figure 9.
Connections shown are for typical aquastat. Actual
connections may vary with specific device used.
NOTE: If a separate transformer is used to supply a Y1, Y2, or
B signal to the unit controls, isolation relays must be used.
CAUTION: Use only copper conductors for field
installed wiring. Terminals in the unit are not
designed for other types of conductors.
WARNING: All wiring must comply with local and
state codes. Disconnect the power supply before
beginning to wire to prevent electrical shock or
equipment damage.
NOTE: Accessory 1 output is selectable as on with
compressor or off with compressor using the unit display.
on with compressor is the factory default setting.
Source Flow Switch (SFS)
Unit is factory shipped with no connections on Flow Switch
pins J10-45 (entering). If flow proving switch is required,
hook up as shown in Fig. 10 and Note 5. The unit will not
operate without flow proving inputs open.
Load Flow Switch (LFS)
Unit is factory shipped with no connections on Flow Switch
pins J9-56 (leaving). If flow proving switch is required, hook
up as shown in Fig. 10 and Note 4. The unit will not operate
without flow proving inputs open.
ATTENTION: Flow Switch inputs must be
made before unit will operate!
Wiring Schematic
SFS
LFS
ES
42
43
44
45
46
47
48
24VAC Com
DI12
DI11
DI10
DI9
DI8
DI7
49
50
51
52
53
54
55
56 DI 3/4/5/6/ Com
DI6
DI5
DI4
DI3
DI2
DI1
9VDC
J10
J9
2
3
1
PB2
Black (54)
Red (55)
Gray (56)
Pink (58)
Brown (57)
Gray (59)
Blue (45)
Blue (46)
Orange (47)
Gray (48) Connect to R on TB
White (67)
White (66)
Blue (76A)
Blue (76B)
NOTE 1
NOTE 2
NOTE 4
NOTE 5
NOTE 8