Carrier WEATHERMASTER 48/50Z030-105 User Manual

Page 45

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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-SPT)

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

*

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