Accessory control components – Carrier WEATHERMASTER 48/50Z030-105 User Manual

Page 122

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122

Table 95 — Thermistors and Unit Operation Control Pressure Transducers

LEGEND

FAN STATUS SWITCH — The units can be equipped with

an optional fan status switch that will monitor the pressure rise

across the indoor fans.
RETURN AIR CO

2

SENSOR — The unit can be equipped

with a return air IAQ CO

2

sensor that is used for the demand

control ventilation. The sensor is located in the return air sec-

tion and can be accessed from the filter access door.
BOARD ADDRESSES — Each board in the system has an

address. The MBB has a default address of 1 but it does have

an instance jumper that should be set to 1 as shown in Fig. 26.

For the other boards in the system there is a 4-dip switch head-

er on each board that should be set as shown below.

0 = On; 1 = Off

Accessory Control Components —

In addition to

the factory-installed options, the units can also be equipped

with several field-installed accessories that expand the control

features of the unit. The following hardware components can

be used as accessories.
ROOM THERMOSTATS — The ComfortLink™ controls

support a conventional electro-mechanical or electronic ther-

mostat that uses the Y1, Y2, W1, W2, and G signals. The

control also supports an additional input for an occupied/

unoccupied command that is available on some new thermo-

stats. The ComfortLink controls can be configured to run with

up to 6 stages of capacity. Although the unit can be configured

for normal 2-stage control, it is recommended that the multi-

stage control be used. The room thermostat is connected to

TB202.

The ComfortLink controls also support the use of space

temperature sensors and can be used with the T55 and T56

sensors. The controls can also be used with CCN communicat-

ing T58 room sensor. The T55 and T56 sensors are connected

to TB202 terminals 8, 9, and 10. The T58 sensor is connected

to the CCN connections on COMM board. Whenever a unit

equipped with heat is operated without a thermostat, the user

must install the red jumpers from R to W1, and W2 on TB202

for the heat function to work correctly.
SPACE CO

2

SENSORS — The ComfortLink controls also

support a CO

2

IAQ sensor that can be located in the space for

use in demand ventilation. The sensor must be a 4 to 20 mA

sensor and should be connected to TB202 terminals 11 and 12.
ECONOMIZER HUMIDITY CHANGEOVER SEN-

SORS — The ComfortLink controls support 5 different

changeover systems for the economizer. These are:
• Outdoor enthalpy switch

• Outdoor air dry bulb

• Differential dry bulb

• Outdoor air enthalpy curves

• Differential enthalpy

• Custom curves (a combination of an enthalpy/dewpoint

curve and a dry bulb curve).
The units are equipped as standard with an outdoor air

enthalpy control. Outside air and return air dry bulb sensors

which support the dry bulb changeover method are also

supplied as standard. If the other methods are to be used, then a

field-installed humidity sensor must be installed for outdoor air

enthalpy and customer curve control and two humidity sensors

must be installed for differential enthalpy. Installation holes are

pre-drilled and wire harnesses are installed in every unit for

connection of the humidity sensors. The ComfortLink controls

have the capability to convert the measured humidity and

dry bulb temperature into enthalpy.

SENSOR

DESCRIPTION AND LOCATION

PART NO.

Thermistors

CCT

Cooling Coil Thermistor input. Provided with factory-option hydronic heat. Located on face of the
hydronic heating coil. Consists of 4 thermistors wired into a 2x2 array.

HH79NZ039 (4)

LST

Limit Switch Thermistor. Provided with Staged Gas Control option. Located in the heating
compartment.

HH79NZ034

OAT

Outside Air Thermistor. Located in top of the return plenum, attached to roof pole.

HH79NZ039

RAT

Return Air Thermistor.
Without Economizer: Located on left side base rail in the return plenum.
With Economizer: Located on left side face of return damper section in the return plenum.

HH79NZ039

SAT

Supply Air Thermistor. Located in the Supply Fan section, on left side of the fan housing.
(May be relocated or replaced when unit is used with CCN Linkage systems; see page 60.)

HH79NZ039

LAT 1,2,3

Leaving Air Thermistors, provided with Staged Gas Control option. Shipped in the heating
compartment. Installer must pull out and mount in the supply duct.

HH79NZ034 (3)

Control Pressure Transducers

BP

Building Pressure. Provided with Modulating Power Exhaust, High-Capacity Power Exhaust
and Return Fan options. Located in the auxiliary control box (left-hand side of unit near return
plenum).

HK05ZG018

DPA

Discharge Pressure (refrigerant), Circuit A. Located on compressor A1 high-side connections.

HK05YZ007

DPB

Discharge Pressure (refrigerant), Circuit B. Located on compressor B1 high-side connections.

HK05YZ007

SPA

Suction Pressure (refrigerant), Circuit A. Located on compressor A1 low-side connections.

HK05YZ001

SPB

Suction Pressure (refrigerant), Circuit B. Located on compressor B1 low-side connections.

HK05YZ001

DSP

Duct Static Pressure. Provided with VAV models equipped with VFD or Inlet Guide Vane options.
Located in the auxiliary control box (right-hand side of unit near return plenum).

HK05ZG010

FT_SF

Supply Air Cfm (velocity pressure). Provided with factory-option return fan system
(sizes 075-105 only). Located in the supply fan compartment, on right side, on vertical post.

HK05ZG015

FT_RF

Return Air Cfm (velocity pressure). Provided with factory-option return fan system
(sizes 075-105 only). Located in auxiliary control box (right-hand side, filter access panel).

HK05ZG07

Outside Air CFM
Control

Outside Air Cfm Monitor (velocity pressure). Provided with the Outside Air Cfm Control option.
Located in auxiliary control box (right-hand side, filter access panel).

50ZZ400290 (030-070)
50ZZ400289 (075-105)

VAV — Variable Air Volume

BOARD

SW1

SW2

SW3

SW4

RCB

0

0

0

0

ECB

1

0

0

0

SCB

0

0

0

0

CEM

0

0

0

0

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