45
50 Hertz Unit? (50.HZ) — Some units are designed to run at
50 Hertz instead of 60 Hertz. Make sure this configuration
matches the frequency called out by the model number of the
unit. This is important as the cooling stage tables are directly
determined based on both the SIZE and 50.HZ configurations.
MAT Calc Config (MAT.S) — This configuration gives the
user three options in the processing of the mixed-air tempera-
ture (MAT) calculation:
•MAT.S = 0
The control will not attempt to learn MAT over time. The
control will simply calculate MAT based on the position of
the economizer, outside and return air temperature, linearly.
•MAT.S = 1
The control will attempt to learn MAT over time. Any time
the system is in a vent mode and the economizer stays at a
particular position for long enough, MAT = EDT (evapora-
tor discharge temperature). Using this, the control has an in-
ternal table whereby it can more closely determine the true
MAT value.
•MAT.S = 2
The control will stop learning and use whatever the control
has already learned. Using this setting infers that the control
has spent some time set to MAT.S = 1.
First set MAT.S = 1, then go into the Service Test mode.
Turn on the fan and open the economizer to a static position for
5 minutes. Move to several positions (20%,40%,60%,80%). It
is important that the difference between return and outside tem-
perature be greater than 5 degrees. (The greater the delta, the
better.) When done, set MAT.S = 2 and the system has been
commissioned.
Reset MAT Table Entries? (MAT.R) — This configuration
allows the user to reset the internally stored MAT learned con-
figuration data back to the default values. The defaults are set
to a linear relationship between the economizer damper posi-
tion and OAT and RAT in the calculation of MAT.
MAT Outside Air Position Default (MAT.D) — This config-
uration is used to calculate MAT when the economizer option
is disabled. The configuration is adjustable from 0 to 100%
outside air. This defines the fixed ventilation position that will
be used to correctly calculate MAT.
Altitude……..In Feet: (ALTI) — As the control does not in-
clude a barometric pressure sensor to define the calculation of
enthalpy and cfm, the control does include an altitude parame-
ter which will serve to set up a default barometric pressure for
use with calculations. The effect of barometric pressure in
these calculations is not great, but could have an effect depend-
ing on the installed elevation of the unit. If the rooftop is
installed at a particularly high altitude and enthalpy or cfm are
being calculated, set this configuration to the current elevation
of the installed rooftop.
Start Up Delay Time (DLAY) — This option inhibits the unit
from operating after a power reset. The configuration may be
adjusted from 0 to 900 seconds of delay.
Auxiliary Relay Configuration (AUX.R) — This configura-
tion allows the user to configure the function of the auxiliary
relay. The configuration can be set from 0 to 3. If AUX.R is set
to 0, the auxiliary relay will be energized during an alarm. The
relay can be used to turn on an indicator light or sound an alarm
in a mechanical room. If AUX.R is set to 1, the auxiliary relay
will energize when the controls determine dehumidification/re-
heat is needed. The relay would be wired to a third party dehu-
midification/reheat device and would energize the device when
needed. If AUX.R is set to 2, the auxiliary relay will energize
when the unit is in the occupied state. The relay could then be
used to control lighting or other functions that need to be on
during the occupied state. If AUX.R is set to 3, the auxiliary re-
lay will energize when the supply fan is energized (and, if
equipped with a VFD, the VFD output is not 0%). The default
is 0.
Space Temp Sensor (SPT.S) — If a space temperature sensor
is installed (T55/T56), enable this configuration.
Space Temp Offset Sensor (SP.O.S) — If a T56 sensor is in-
stalled with the space temperature offset slider, enable this con-
figuration.
Space Temp Offset Range (SP.O.R) — If a space tempera-
ture offset sensor is installed, it is possible to configure the
range of the slider by adjusting this range configuration.
Space Air RH Sensor (SRH.S) — If a space relative humidity
sensor is installed, enable this configuration.
Return RH Sensor (RRH.S) — If a return air relative humidi-
ty sensor is installed, enable this configuration.
Filter Status Switch Enabled? (FLT.S) — If a filter status
switch is installed, enable this configuration to begin the moni-
toring of the filter status input (Inputs
→
GEN.I
→
FLT.S). See
the Dirty Filter Switch section for more details on installation
and operation.
Cooling Control — The Z Series ComfortLink™ con-
trols offer two basic control approaches to mechanical cooling:
2-stage cooling (CV) and multiple stages of cooling (VAV). In
addition, the ComfortLink control offers the ability to run
multiple stages of cooling for either a space temperature sensor
or thermostat by controlling the unit to either a low or high cool
supply air set point. The control type (Configuration
→
UNIT
→
C.TYP) determines the selection of the type of cooling
control as well as the technique for selecting a cooling mode.
Unit staging tables are shown in Appendix C.
NOTE: Whether a unit has a VFD, inlet guide vanes, or a
supply fan installed for static pressure control has no effect on
configuration of the machine control type (C.TYP). No matter
what the control type, it is possible to run the unit in either CV
or VAV mode provided there are enough stages to accommo-
date lower air volumes for VAV operation. Refer to the section
on static pressure control on page 61 for information on how to
set up the unit for the type of supply fan control desired.
SETTING UP THE SYSTEM
Machine Control Type (Configuration
→
UNIT
→
C.TYP) —
The most fundamental cooling control configuration is located
under Configuration
→
UNIT.
*This default is model number dependent.
This configuration defines the technique and control source
responsible for selecting a cooling mode and in determining the
method by which compressors are staged. The control types
are:
•C.TYP = 1 (VAV-RAT) and C.TYP = 2 ( VAV- S PT )
Both of these configurations refer to standard VAV opera-
tion. If the control is occupied, the supply fan is run continu-
ously and return-air temperature will be used for both in the
determination of the selection of a cooling mode. VAV-SPT
differs from VAV-RAT only in that during the unoccupied
period, space temperature will be used instead of return-air
temperature to start the fan for ten minutes before the
return-air temperature is allowed to call out any mode.
•C.TYP = 3 (TSTAT – MULTI)
This configuration will force the control to monitor the ther-
mostat inputs to make a determination of mode. Unlike tra-
ditional 2-stage thermostat control, the unit is allowed to use
multiple stages of cooling control and perform VAV style
operation. The control will be able to call out a LOW
ITEM EXPANSION RANGE CCN
POINT DEFAULTS
UNIT UNIT CONFIGURATION
C.TYP Machine Control Type 1 - 6 CTRLTYPE *