JOHNSON CONTROLS
102
FORM 100.50-NOM12
ISSUE DATE: 04/02/2019
SECTION 5 – SEQUENCE OF OPERATION
Continuous Ventilation
• This sequence is only applicable on SZVAV con-
figured units.
• Continuous ventilation can be User Enabled/User
Disabled in the PROGRAM-VENTILATION menu:
1. User Enabled: The supply fan operates con-
tinuously when the unit is in the Occ mode.
2. User Disabled: The supply fan only operates
with a cooling or heating demand when the
unit is in the Occ mode.
• When the unit mode is Occ Standby, the supply
fan operates at the SZVAV minimum fan speed.
• When the unit is in an Unocc mode, the supply
fan only operates with a demand for cooling or
heating.
Comfort Ventilation
• The comfort ventilation sequence is only appli-
cable on SZVAV configured units.
• Comfort ventilation can be User Enabled/User
Disabled in the PROGRAM-VENTILATION
menu.
• Comfort ventilation is typically utilized on units
that have a large amount of outside air being
drawn in for ventilation purposes.
• It has two different modes:
1. Comfort ventilation cool
2. Comfort ventilation heat
Comfort Vent Cool Sequence of Operation
• Comfort ventilation must be User Enabled in the
PROGRAM-VENTILATION menu.
• The unit must be in an Occ mode.
• The unit must have a valid zone temperature read-
ing.
• When the current SAT becomes greater than the
occ zone cooling setpoint by 5.0°F, the IPU board
starts the unit in occ cooling low.
• When the current SAT becomes less than the occ
zone cooling setpoint by 5.0°F for 5 minutes, the
IPU board stops comfort ventilation cool.
Comfort Ventilation Heat Sequence of
Operation
• Comfort ventilation must be User Enabled in the
PROGRAM-VENTILATION menu.
• The unit must be in an Occ mode.
• The unit must have a valid zone temperature read-
ing.
• If the current SAT becomes less than the occ zone
heating setpoint by 5.0°F, the IPU board starts the
unit in occ heating low.
• When the current SAT becomes greater than the
occ zone heating setpoint by 5.0°F for 5 minutes,
the IPU board stops comfort ventilation heat.
EXHAUST/RETURN FAN
• The Series 100 units can be ordered with either
an optional exhaust fan assembly or return fan as-
sembly, but not both.
• The exhaust fan assembly may or may not have an
exhaust fan VFD.
• An exhaust fan assembly only runs when called
for by either damper position or building pressure.
• An exhaust fan assembly has one motor and one
VFD that drives two blower wheels. See
LD28130
FIGURE 53 -
EXHAUST FAN ASSEMBLY