9
JOHNSON CONTROLS
FORM 115.20-NOM6 (1106)
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
TB3-3/TB2-5 jumper is in place, the fan will con-
tinue to operate at the fan speed selected. Removing
the jumper will cause the fan to shut down when the
thermostat is satisfied.
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 YCW-HW with Both a Chilled Water Coil and a
Hot Water Coil.
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
TB3-3/TB2-5 jumper is in place, the fan will con-
tinue to operate at the fan speed selected. Removing
the jumper will cause the fan to shut down when the
thermostat is satisfied.
When using the T421 auto C/O thermostat and the
TB3-3/TB2-5 jumper is in place, the fan will con-
tinue to operate at the fan speed selected. Removing
the jumper will cause the fan to shut down when the
thermostat is satisfied.
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
TB3-3/TB2-5 jumper is in place, the fan will con-
tinue to operate at the fan speed selected. Removing
the jumper will cause the fan to shut down when the
thermostat is satisfied.
When using the T421 auto C/O thermostat and the
TB3-3/TB2-5 jumper is in place, the fan will con-
tinue to operate at the fan speed selected. Removing
the jumper will cause the fan to shut down when the
thermostat is satisfied.
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.
