Johnson Controls 100 Series Manual

JOHNSON CONTROLS
30
FORM 100.50-SU8
ISSUE DATE: 1/28/2016
SECTION 11 - SERIES 100: FLEXSYS OPERATION
FLEXSYS: COOLING
Occupied
Whenever a Flexsys unit enters an Occ Cooling mode,
it will always start in the Occ Cooling w/o Bypass
mode for the first 30 seconds. After this time delay has
expired, the unit controller will determine which mode
it needs to be in: Occ Cooling w/o Bypass or Occ Cool-
ing w/ Bypass.
The programmable option, SAT RESET,
is not utilized on Flexsys congured units.
If the need arises to reset the MX SAT SP
on a Flexsys congured unit, it will need
to be done through the BAS.
Occ Cooling w/o Bypass
The unit controller will cycle the compressors or mod-
ulate the economizer to achieve and maintain the MX
SAT S P.
• If the economizer is active, the unit will remain in
the Occ Cooling w/o Bypass mode
OR
• If the RAT ≥ RAT SP plus 0.5 °F BUT RAT <
MX SAT SP + the RA Diff SP (user adjustable
between2.0–10.0°F)
Occ Cooling w/ Bypass
If the RAT≥ RATSP plus 0.5 °F AND RAT > MX
SAT SP + the RA Diff SP (user adjustable between
2.0–10.0°F).
The unit controller will cycle the compressors to main-
tain either the Evap Leaving Air Temp High SP or the
Evap Leaving Air Temp Low SP.
The unit controller will modulate the Flexsys Bypass
Damper open/closed to achieve and maintain the MX
SAT S P.
Evap Leaving Air Temp High SP
• R/A Humidity sensor is not reliable
OR
• R/A Enthalpy < the Reset Enthalpy SP
Evap Leaving Air Temp Low SP
• R/AEnthalpyis≥ResetEnthalpySP
OR
• Underoor Slab Dewpoint is ≥ Underoor Slab
Temp–2.0°Ffor120seconds(OnlyifDewPoint
Reset is User Enabled)
Return Air Bypass
Current %: This is the amount of air the unit control-
ler believes it is bypassing due to the fact that the MX
SAT is not increasing. The unit controller utilizes the
current RAT, the Current Evap Leaving Air Temp, and
the MX SAT to perform a calculation to arrive at the
Current %.
Active SP %: This is how much of the return air the
unit controller believes it needs to bypass to warm the
MX SAT from its current value to the MX SAT SP.
The unit controller utilizes the current RAT, the current
Evap Leaving Air Temp, and the current MX SAT to
perform a calculation to arrive at the Active SP %.
Both of the above numbers are based on internal al-
gorithms and logic built into the unit controller. The
algorithms and internal logic are not user adjustable.
Bypass Damper Position
This is the actual position of the bypass damper. The
bypass damper should be able to drive between 0% and
40%.
Bypass Damper Operation
The operation of the bypass damper is very slow and
the logic that drives the damper is quite complicated.
When the unit is in normal operation, it could take up
to 30 mins for the bypass damper to go from 0% to
40%. If the unit is operating properly and the tempera-
tures are in the proper range, the damper will probably
never drive to 40%.
Max Bypass
This is the maximum amount of return air that the unit
controller will allow to bypass around the evaporator
coil through the Flexsys Bypass Damper. The unit con-
troller will utilize internal logic and calculations to de-
termine how much of the return air is being bypassed.
This is not the same as the actual bypass damper posi-
tion. This is an adjustable SP with a range of 20%–
40%. We recommend leaving it at 40% for initial start-
up and then adjusting down later if need be.
It is very likely that the above mentioned
parameters, RETURN AIR BYPASS
CURRENT %, RETURN AIR BYPASS
ACTIVE SP %, and BYPASS DAMPER
POSITION % will not have matching
values. This is normal, do not be alarmed.

Johnson Controls 100 Series Specifications

General

Brand	Johnson Controls
Model	100 Series
Category	Air Conditioner
Language	English