Johnson Controls
5586996-JSG-A-0120 | Start-Up & Operation Guide
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Unit Type
The rooftop unit can be ordered in one of the two avail-
able unit configurations:
• Multi zone variable air volume (MZVAV)
• Single zone variable air volume (SZVAV).
Both unit configurations have specific sequences that
operate differently from each other.
MZVAV is the default unit type. SZVAV must be user
enabled in the
Commissioning > Standard > SZVAV
Enabled
menu.
Occupancy Mode
• The rooftop units can operate in the following oc-
cupancy modes
• Occupied (OCC)
• Unoccupied (UNOCC)
• Morning warm-up/cool down
• Coast
• There are three source of occupancy available
when the occupancy mode is set to external. A
command of occupied on any of the following in-
puts results in occupied operation
• From a BAS
• Tenant override through a zone sensor
• Hard wired input
• When the occupancy mode is set to schedule, the
occupancy is determined by the internal schedule
of the control
Morning Warm-up/Cool Down
External Mode
With a binary input occupied command, the supply fan
turns on for a 5 minute stabilization period, and the
operating space temperature is compared to morning
warm-up and morning cool down setpoints.
When the operational zone temperature is equal to
or below the morning warm-up return air temperature
(RAT) setpoint, heating operates for at least 5 minutes.
If the operational zone temperature is above the morn-
ing warm-up setpoint, the control goes into occupied
mode. Heating runs until 5 minutes pass and the oper-
ational zone temperature is above the morning warm-
up setpoint or the early start period expires. The control
goes into occupied mode thereafter.
When the operational zone temperature is equal to or
above the morning cool down RAT setpoint, cooling
operates for at least 5 minutes. When the operation-
al zone temperature is below the morning cool down
setpoint, the control goes into occupied mode. Cool-
ing runs until 5 minutes pass and the operational zone
temperature is below the morning cool down setpoint
or the early start period expires. The control goes into
occupied mode thereafter.
Optimal Start
Historical data, operational zone temperature, OCC
setpoint, and OAT determine when optimal start be-
gins. The optimal start time is always within the same
calendar day. The control uses the occupied heating
and occupied cooling setpoints to determine when the
demand is satisfied. The control goes into occupied
mode thereafter.
Schedule
At the early start period prior to the scheduled occu-
pancy, the supply fan turns on for a 5 minute stabili-
zation period, and the operating space temperature is
compared to morning warm-up and morning cool down
setpoints.
When the operational zone temperature is equal to or
below the morning warm-up RAT setpoint, heating op-
erates for at least 5 minutes. If the operational zone
temperature is above the morning warm-up setpoint,
the control goes into occupied mode. Heating runs until
5 minutes pass and the operational zone temperature
is above the morning warm-up setpoint or the early
start period expires. The control goes into occupied
mode thereafter.
When the operational zone temperature is equal to or
above the morning cool down RAT setpoint, cooling
operates for at least 5 minutes. When the operation-
al zone temperature is below the morning cool down
setpoint, the control goes into occupied mode. Cool-
ing runs until 5 minutes pass and the operational zone
temperature is below the morning cool down setpoint
or the early start period expires. The control goes into
occupied mode thereafter.
Coast
The coast sequence allows the unit to raise or lower
the active cooling or heating SPs 2 hours (user adjust-
able) prior to the transition from OCC to UNOCC.
This sequence allows for added energy conservation
from the unit.
When coast is user enabled, the unit controller raises
the active cooling setpoint 1.0°F per hour or lowers the
active heating setpoint 1.0°F per hour (user adjustable).
