153
JOHNSON CONTROLS
5276178-JIM-C-0118
5
1.0°F the Unit Control will energize the heating
sequence based on the “MORNING WARM UP
OPTIME”.
5. The Unit Control sets the
“SUPPLY AIR TEMP
ACTIVE SP”
as follows:
•
Variable Air Volume and FlexSys units it is
the
“HEATING SAT”.
•
CV units it is the
“2ND STAGE HEATING
SETPOINT”.
6. The heat source remains energized until the Return
Air Temperature is more than or equal to the
“RAT
HEATING SETPOINT”
plus 0.5°F or the unit goes
into the occupied mode.
7. The Unit Control records the time the heat source
is energized as described below:
a) If the heat source was terminated because
it was within 0.5°F of the
“RAT HEATING
SETPOINT”
the Unit Control replaces the
Day 3 time with the Day 2 time; the Day 2
time with the Day 1 time and replaces the Day
1 time with the current value. It then averages
the three values and adds 10 minutes and this
becomes the new
“MORNING WARM UP
OPT TIME”
for the next day.
b) If the heat source does not bring the
“RE-
TURN AIR TEMP”
up to the
“RAT HEATING
SETPOINT”
before the Morning Warm Up is
stopped the Unit Control calculates a approxi-
mate daily warm up time using the following
formula.
Warm
Up
Time
x (Setpoint – Temp1)
T I M E
TEMP 2 –
TEMP 1
{ }
=
Where:
•
Warm Up time = time to be recorded as the
Daily Warm Up Time.
•
Time = Elapsed time when Warm Up
Stopped.
•
TEMP2 =
“RETURN AIR TEMP”
when the
Warm Up stopped.
•
TEMP1 =
“RETURN AIR TEMP”
when the
Warm Up started.
•
Set Point =
“RAT HEATING SETPOINT”.
If the time from when heat is started and Morning
Warm Up is stopped is less than 10 minutes, the
Unit Control will use the daily warm up time for
the previous day and will not approximate a warm
up time.
If the approximate daily warm up time exceeds the
“MORNING WARM UP MAX TIME”, the daily
warm up time will be set equal to the “MORNING
WARM UP MAX TIME”.
FLEXSYS UNDER FLOOR TEMPERATURE
CONTROL
Programmed Data
The following parameters must be programmed into
the Unit Controller:
•
“ACTIVE SLAB CONTROL”
must be set to
USER ENABLED under the PROGRAM key,
COOLING subsection of the User Interface.
•
“DEW POINT RESET”
must be set to USER
ENABLED under the PROGRAM key, COOL-
ING subsection of the User Interface.
•
“HEATING SYSTEM”
must be set to USER EN-
ABLED under the PROGRAM key, HEATING
subsection of the User Interface.
Under Floor Heating Sequence of Operation
Occupied Standby
1. The Unit Control checks the
“UNDERFLOOR
SLAB TEMP”
immediately after transitioning from
Unoccupied to Occupied Standby mode.
2. If the
“UNDERFLOOR SLAB TEMP”
is less
than or equal to the
“MX SUPPLY AIR TEMP
SETPOINT”
minus 2.0°F, the
“UNDER FLR
TEMP OVRD”
shall be set to active.
3. The
“UNDERFLOOR TEMP CONTROL SP”
is
set to the
“MX SUPPLY AIR TEMP SETPOINT”
plus 10.0°F.
4. The Unit Control then generates a call for one stage
of heat for staged heat operation or controls the
“SUPPLY AIR TEMPERATURE”
to the
“UNDER-
FLOOR TEMP CONTROL SP”
for modulating
heat.
5. Heating operation will continue until:
Summary of Contents for 40 25 TON
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