WaterFurnace Series NXW - Manual (Page 20)

20
ENVISION 2 NKW 50Hz REVERSIBLE CHILLER INSTALLATION MANUAL
Field Wiring and Control Setup cont.
Accessory Relay Setup
The accessory output set to “close” upon Y1 compressor call
(compressor is delayed 90 sec. after Y1) but can be set to
“open” with Y1.
To change ACC1:
• Using up and down keys, scroll to “Acc 1 Sel” hit “ENTER”
and “ON Comp” begins flashing
• Using up and down keys, select “ON Comp” for activation
with Y1 Call or “OFF Comp” for deactivation with Y1
Lead/Lag Selection
Compressor Lead/Lag Selection is factory set to “ON” but
can be set to “OFF”.
To change Lead/Lag On/Off:
• Using up and down keys, scroll to “LEAD/LAG SELECT”
hit “ENTER” and “ON” begins flashing
• Using up and down keys, select “ON” for activation or “
OFF” for deactivation
Anti Short Cycle
High Pressure Protection
Low Pressure Protection
Advanced Freeze Detection Setpoint
Random Start
Display for diagnostics
Reset Lockout at disconnect
Intelligent reset for field installed flow switches
1 Accessory output
Compressor Lead/Lag
Compressor Current Switches
Field Selectable Options
Freeze Detection Sensing Select (DI-4 and DI-5)
The freeze detection temperature sensing selection inputs
allow the user to adjust the setpoints. The source sensors
are wired to inputs AI-3 and AI-4 while the load sensors
are wired to inputs AI-5 and AI-6. The setpoints for both,
the load and source, are factory set for 0.56°C. In order to
change the setpoint to -9.4°C on the source, remove the
jumper wire from DI-4 (wire #56). The load setpoint can be
changed by removing the jumper wire from DI-5 (wire #55).
Accessory Output (DO-4)
The accessory output will be energized 90 seconds prior to
the lead compressor output being energized. When the lead
compressor output is turned off the accessory output will be
deactivated after 90 seconds. The output is selectable for on
with compressor or off with compressor operation through
the unit mounted user interface.
°F or °C - Unit of Measure
Degrees Fahrenheit is factory set, however degrees Celsius
can be selected using the following procedure:
To Change Unit of Measure:
• On FX10 control using up and down keys, scroll to
“SETTINGS”
• Using up and down keys, scroll to “UNIT OF MEASURE”
hit “ENTER” and “UNIT OF MEASURE” begins flashing
• Using up and down keys, select “F” for degrees
Fahrenheit or “C” for degrees Celsius
Other Field Options
Other field selectable options are available as shown in the
maintenance menu on page 24 of the FX10 control using a
similar procedure as shown in the above examples. These
would include aquastat enabling, and emergency shutdown.
Control Features
Control and Safety Features
Emergency Shutdown
The emergency shutdown mode can be activated by a
command from a facility management system or a closed
contact on DI-2. The default state for the emergency
shutdown data point is off. When the emergency shutdown
mode is activated, all outputs will be turned off immediately
and will remain off until the emergency shutdown mode is
deactivated. The first time the compressor starts after the
emergency shutdown mode has been deactivated, there will
be a random start delay present.
Lockout Mode
Lockout mode can be activated by any of the following
fault signals: refrigerant system high pressure, refrigerant
system low pressure, heating freeze detection, cooling
freeze detection, and compressor current sensor. When
any valid fault signal remains continuously active for the
length of its recognition delay, the controller will go into fault
retry mode, which will turn off both compressors. After the
compressor short cycle delay, the compressors will attempt
to operate once again. If three consecutive faults occur in 60
minutes, the unit will go into lockout mode, turning off the
compressor(s), enabling the alarm output until the controller
is reset. If the control faults due to the low pressure input
being open during the pre-compressor startup check, the
control will go into lockout mode immediately, disabling the
compressors from starting and enabling the alarm output.
The lockout condition can be reset by powering down the
controller, by a command from the BAS, or by the holding
the ESC and Return keys on the user interface for 5 seconds.