Johnson Controls 100 Series User Manual

JOHNSON CONTROLS
96
FORM 100.50-NOM12
ISSUE DATE: 04/02/2019
SECTION 5 – SEQUENCE OF OPERATION
Freeze Protection
• On Series 100 units with hot water/steam coils, the
IPU board has a built in freeze protection sequence.
• The freeze protection sequence is not adjustable.
• There are two different sequences for freeze pro-
tection:
1. Supply fan ON, heating is inactive
1. When the supply fan is running, the IPU
board monitors the current SAT.
2. When the current SAT becomes equal to/
less than 38.0°F, the IPU board sends a 0–10
VDC signal to open the hot water/steam
valve to maintain the current SAT at 38.0°F.
2. Supply fan OFF, heating is inactive
1. When the supply fan is OFF, the IPU board
monitors the current OAT.
2. When the current OAT becomes equal to/
less than 40.0°F, the IPU board sends a 0–10
VDC signal to the hot water/steam valve to
fully open the valve.
Freeze Fault
• The IPU board monitors the status of the factory
installed freezestat.
• When the freezestat is ON (open), it closes on
when the temperature drops to 35.0°F.
• When the freezestat closes for 10 seconds, the IPU
board fully opens the hot water/steam valve, and a
WRN- TRIP FREEZESTAT is declared.
• The IPU starts a 5 minute Freeze Trip Timer.
• If at any time during this 5 minutes, the freezestat
returns to normal operation, open, the unit resumes
normal operation and the warning is cleared.
• If the freezestat remains closed for 5 minutes, the
IPU shuts down the unit and a Lockout-Hot Water
Freeze Fault is declared.
Heating Sequences
• The Series 100 unit has several different sequenc-
es associated with the different heating options.
• Each of these sequences can be User Enabled/User
Disabled in the PROGRAM-HEATING menu.
• They can also be User Enabled/User Disabled
through a BAS.
Morning Warm-Up
• Morning warm-up is a sequence that typically
warms a building to a comfortable temperature
before personnel arrive.
• The morning warm-up sequence on Series 100
units can only be started from an Unocc mode.
• Morning warm-up can be started either from the
IPU board internal schedule or from a BAS.
Morning Warm-Up Setup
• The Series 100 unit must have one of the op-
tional heating types installed.
• Morning warm-up must be User Enabled in
the PROGRAM-HEATING menu.
• Morning warm-up uses the current RAT to
determine if the heating source should be
turned ON.
Morning Warm-Up Sequence of Operation
• The current unit mode must be Unocc Stand-
by.
• A command for morning warm-up must be
received from either the BAS or the internal
clock schedule.
• Once the IPU board receives the morning
warm-up command, the supply fan starts (the
return fan also starts if installed).
• The supply fan is controlled as follows:
1. VAV or FlexSys: To the active duct stat-
ic pressure setpoint
2. SZVAV: At 100%
• After the supply is ON for 5 minutes, the IPU
board compares the current RAT to the active
RAT heating setpoint.
• When the current RAT is equal to/less than
the active RAT setpoint minus 1.0°F, the
unit’s heating source is turned ON.
• The heating source is controlled to the fol-
lowing setpoints:
1. VAV or FlexSys: SAT heating
2. SZVAV: 2nd stage heating

Johnson Controls 100 Series Specifications

General

Brand	Johnson Controls
Model	100 Series
Category	Air Conditioner
Language	English