JOHNSON CONTROLS
111
SECTION 5 – SEQUENCE OF OPERATION
FORM 100.50-NOM12
ISSUE DATE: 04/02/2019
5
Sequence: Unoccupied to Occupied
• The IPU board checks the underfloor slab
temperature immediately after switching from
Unocc Standby to Occ Standby. (If the unit
transitions to Occ Cooling with or without
Bypass during this time, active slab control is
terminated.)
• When the underfloor slab temperature is less
than the active mixed SAT setpoint minus
2.0°F, the underfloor temperature override
becomes active.
• The IPU board activates the unit heating
source and start a 20 minute Active Slab
Control Timer.
1. Staged Gas or Electric Heat
• The IPU board starts the first stage
of heat.
2. Modulating Gas or Hot Water /Steam
Heat
• The IPU board controls the heat-
ing source to the active mixed SAT
setpoint plus 10.0°F.
• Heating operation continues until either of the be-
low are true:
• The underfloor slab temperature is greater
than the active mixed SAT setpoint.
• The 20 minute Active Slab Control Timer
has expired.
Sequence: Occupied to Unoccupied
• The IPU board checks the underfloor slab
temperature immediately after switching
from an Occ to Unocc Standby mode.
• When the underfloor slab temperature is
greater than the current RAT minus 2.0°F, the
underfloor temp override becomes active.
• The IPU board activates the unit heating
source and start a 20 minute Active Slab
Control Timer.
1. Staged Gas or Electric Heat
• The IPU starts the first stage of heat.
2. Modulating Gas or Hot Water /Steam
Heat
• The IPU board controls the heat to
the active mixed SAT setpoint plus
10.0°F.
• Heating operation continues until either one
of the following are true:
• The underfloor slab temperature is
greater than the current RAT plus 1.0°F.
• The 20 minute Active Slab Control
Timer has expired.
Supply Air Temp. Setpoint Reset
Duct Pressure Setpoint Reset
25
26
22
DSP- (DUCT STATIC RESET -)
DSP+ (DUCT STATIC RESET +)
+5V (DUCT STATIC SP + 5V)
+5V (SAT SP + 5V)
URH - (FLEXSYS UNDERFLOOR RH -)
URH + (FLEXSYS UNDERFLOOR RH +)
SHLD - (SHIELD (GND))
SHLD - (SHIELD (GND))
ZR - (ZONE TEMP SENSOR -)
ZR + (ZONE TEMP )
W2 - (2nd STAGE HEATING)
Y2 - (2nd STAGE COOLING)
Y1 - (1st STAGE COOLING)
G - (FAN (G))
SMK3 - (SMOKE PURGE 3)
SMK2 - (SMOKE PURGE 2)
SMK1 - (SMOKE PURGE 1)
OCC - (OCCUPIED/UNOCCUPIED)
SD - (SHUTDOWN)
24V - (24VAC)
24V -
(24VAC)
COM -
(24VAC
COM)
W1 - (1st STAGE HEATING)
SHLD - (FLEXSYS SLAB SENSOR -)
SHLD + (FLEXSYS SLAB )
SAT - (SUPPLY AIR TEMP RESET -)
SAT + (SUPPLY AIR TEMP RESET +)
1
Source Supply for
Remote Sensors of
Controls 40VA Max
LD08184D
FIGURE 58 -
CTB1 FIELD CONTROL WIRING INPUTS