FORM
SEQUENCE OF OPERATION
YCW With a Chilled Water Coil
The unit will respond to a cooling command from the thermostat by powering a water control valve open. The fan will operate at the speed selected at the thermostat. When the space reaches the temperature setpoint at the thermostat, the cooling valve will close and the fan will continue to operate.
When using the T420 manual C/O thermostat and the
When using the T200 thermostat, the stat will auto- matically regulate the fan speed based on the differ- ence between the space temp and setpoint - @ 4˚F off setpoint, the fan will run @ HI; @ 3˚F off setpoint, the fan will run @ MED; @ 2˚F off setpoint, the fan will run @ LO. When the thermostat is satisfied, the water valve will be deenergized and the fan will revert to LO speed.
The
The unit control thermostat, on a call for heating, will energize the hot water control valve. When the ther- mostat is set for cooling, it will energize the chilled water valve on a call for cooling. The fan will operate at the speed selected at the thermostat. When the space reaches the temperature setpoint at the thermostat, the cooling valve will close (on cooling) or the heating valve will close (on heating) and the fan will continue to operate.
When using the T420 manual C/O thermostat and the
When using the T421 auto C/O thermostat and the
When using the T200 thermostat, the stat will auto- matically regulate the fan speed based on the differ- ence between the space temp and setpoint - @ 4˚F off setpoint, the fan will run @ HI; @ 3˚F off setpoint, the fan will run @ MED; @ 2˚F off setpoint, the fan will run @ LO. When the thermostat is satisfied, the water valve will be deenergized and the fan will revert to LO speed.
The YCWE With Both a Chilled Water Coil and Electric Heating Coil.
The unit control thermostat, on a call for heating, will energize the heater contactor(s). When the thermostat is set for cooling, it will energize the chilled water valve on a call for cooling. The fan will operate at the speed selected at the thermostat. When the space reaches the temperature setpoint at the thermostat, the cooling valve will close (on cooling) or the heat- ing contactors will open (on heating) and the fan will continue to operate.
When using the T420 manual C/O thermostat and the
When using the T421 auto C/O thermostat and the
When using the T200 thermostat, the stat will auto- matically regulate the fan speed based on the differ- ence between the space temp and setpoint - @ 4˚F off setpoint, the fan will run @ HI; @ 3˚F off setpoint, the fan will run @ MED; @ 2˚F off setpoint, the fan will run @ LO. When the thermostat is satisfied, the water valve will be deenergized (on cooling) or the heating contactor will open (on heating) and the fan will revert to LO speed.
JOHNSON CONTROLS | 9 |