Controls, Start-Up, Operation, Service and ... - Climayoreo

set point (ConfigurationIAQAQ.SP menu) and the supply
fan is on, the economizer minimum vent position (ConfigurationIAQDCV.CEC.MN)
is overridden and the
damper is moved to the IQ.P.O configuration. When the DAQ
falls below the DAQ.L set point (ConfigurationIAQAQ.SP
menu), the economizer damper is moved
back to the minimum vent position (EC.MN).
NOTE: Configuration OAQ.U is used in the calculation of the
trip point for override and can be found under Configuration
IAQAQ.SP.
IQ.A.C = 3 (4 to 20 mA Damper Control) — This configuration
will provide full 4 to 20 mA remotely controlled analog input
for economizer minimum damper position. The 4 to 20 mA
signal is connected to terminals TB201-8 and TB201-7. The
input is processed as 4 mA = 0% and 20 mA = 100%, thereby
giving complete range control of the effective minimum
position.
The economizer sequences can be disabled by unpluging
the enthalpy switch input and not enabling any other economizer
changeover sequence at ConfigurationECONE.SEL.
Complete control of the economizer
damper position is then possible by using a 4 to 20 mA economizer
minimum position control or a 0 to 10 kilo-ohm 0 to
100% economizer minimum position control via configuration
decisions at ConfigurationIAQIQ.A.C.
To disable the standard enthalpy control input function,
unplug the enthalpy switch and provide a jumper from TB201-
6 to TB201-5 (see wiring diagrams in Major System Components
section on page 116).
IQ.A.C = 4 (10 Kohm Potentiometer Damper Control) —
This configuration will provide input for a 10 kilo-ohm linear
potentiometer that acts as a remotely controlled analog input
for economizer minimum damper position. The input is processed
as 0 ohms = 0% and 10,000 ohms = 100%, thereby giving
complete range control of the effective minimum position.
NOTE: For complete economizer control, the user can make
the economizer inactive by unplugging the enthalpy switch
connection.
CONTROLS OPERATION
Modes — The ComfortLink controls operate under a
hierarchy of command structure as defined by three essential
elements: the System mode, the HVAC mode and the Control
mode. The System mode is the top level mode that defines three
essential states for the control system: OFF, RUN and TEST.
The HVAC mode is the functional level underneath the
System mode which further defines the operation of the
control.
The Control mode is essentially the control type of the unit
(ConfigurationUNITC.TYP). This defines from where
the control looks to establish a cooling or heating mode.
Furthermore, there are a number of modes which operate
concurrently when the unit is running. The operating modes of
the control are located at the local displays under Operating
Modes. See Table 30.
Currently Occupied (OCC) — This variable displays the current
occupancy state of the unit.
Timed Override in Effect (T.OVR) — This variable displays
if the state of occupancy is currently occupied due to an
override.
DCV Resetting Minimum Position (DCV) — This variable
displays if the economizer position has been lowered from its
maximum vent position due to demand control ventilation.
Supply Air Reset (SA.R) — This variable displays if the supply
air set point that the rooftop is attempting to maintain is
currently being reset upwards. This applies to cooling only.
40
Table 30 — Operating Modes Display Table
ITEM EXPANSION RANGE CCN POINT
SYS.M ascii string n/a
HVAC ascii string n/a
CTRL ascii string n/a
MODE MODES CONTROLLING UNIT
OCC Currently Occupied ON/OFF MODEOCCP
T.OVR Timed Override in Effect ON/OFF MODETOVR
DCV DCV Resetting Min Pos ON/OFF MODEADCV
SA.R Supply Air Reset ON/OFF MODESARS
DMD.L Demand Limit in Effect ON/OFF MODEDMLT
T.C.ST Temp.Compensated Start ON/OFF MODETCST
IAQ.P IAQ Pre-Occ Purge Active ON/OFF MODEIQPG
LINK Linkage Active — CCN ON/OFF MODELINK
LOCK Mech.Cooling Locked Out ON/OFF MODELOCK
H.NUM HVAC Mode Numerical Form number MODEHVAC
Demand Limit in Effect (DMD.L) — This variable displays
if the mechanical cooling capacity is currently being limited or
reduced by a third party.
Temperature Compensated Start (T.C.ST) — This variable
displays if Heating or Cooling has been initiated before occupancy
to pre-condition the space.
IAQ Pre-Occupancy Purge Active (IAQ.P) — This variable
displays if the economizer is open and the fan is on to preventilate
the building before occupancy.
Linkage Active CCN (LINK) — This variable displays if a
linkage master in a zoning system has established “linkage”
with this air source (rooftop).
Mechanical Cooling Locked Out (LOCK) — This variable
displays if mechanical cooling is currently being locked out
due to low outside air temperature.
HVAC Mode Numerical Form (H.NUM) — This is a numerical
representation of the HVAC modes which may be read via
a point read.
SYSTEM MODES (Operating ModesSYS.M)
System Mode Off — When the system mode is OFF, all outputs
are to be shut down and no machine control is possible.
The following list displays the text assigned to the System
Mode when in the OFF mode and the conditions that may
cause this mode are checked in the following hierarchal order:
1. Wake up timer on a power reset.
(“Initializing System ...”)
2. System in the process of shutting down compressors and
waiting for timeguards to expire.
(“Shutting Down ...”)
3. Factory shut down (internal factory control level —
SHUTDOWN).
(“Factory Shut Down”)
4. Unit Stop (software application level variable that acts as
a hard shut down — Service TestSTOP).
(“Local Machine Stop”)
5. Fire Shut Down (fire shutdown condition based on the
Fire Shutdown Input (InputsFIREFSD).
(“Fire-Shutdown Mode”)
6. Emergency Stop, which is forced over the CCN through
the Emergency Stop Variable (EMSTOP).
(“CCN Emergency Stop”)
7. Start-up Delay.
(“Startup Delay = 0-900 secs”)
8. Service test ending transition timer.
(“Service Test Ending”)
9. Unexplained internal software failure.
(“Internal Failure”)