Carrier WEATHERMASTER 48/50Z030-105 User Manual

Page 120

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120

Table 92 — Field Terminal Connections (cont)

LEGEND

Table 93 — IGC Board Inputs and Outputs

SCROLLING MARQUEE — This device is the keypad in-

terface used to access the control information, read sensor

values, and test the unit. The scrolling marquee display is a

4-key, 4-character, 16-segment LED display as well as an

Alarm Status LED. See Fig. 30. The display is easy to operate

using 4 buttons and a group of 11 LEDs that indicate the

following menu structures:
• Run Status

• Service Test

• Temperatures

• Pressures

• Set points

• Inputs

• Outputs

• Configuration

• Timeclock

• Operating Modes

• Alarms

Through the scrolling marquee, the user can access all the

inputs and outputs to check on their values and status. Because

the unit is equipped with suction pressure transducers and

discharge saturation temperature sensors, the scrolling marquee

can also display pressures typically obtained from gages. The

control includes a full alarm history, which can be accessed

from the display. In addition, through the scrolling marquee the

user can access a built-in test routine that can be used at start-

up commission and to diagnose operational problems with the

unit. The scrolling marquee is located in the main control box

and is standard on all units.
SUPPLY FAN — The 48/50Z030-050 units are equipped with

a single 25 x 25-in. forward-curved fan. The 48/50Z055-070

units are equipped with a single 30 x 27-in. forward-curved

fan. The 48/50Z075-105 units are equipped with either a single

36 x 30-in. forward-curved fan or a 36-in. airfoil fan. The fan

sleds are spring isolated and driven by a single, 3-phase motor.

The fan is controlled directly by the ComfortLink™ controls.
VARIABLE FREQUENCY DRIVE (VFD) — On variable

air volume units with optional VFD, the supply fan speed is

controlled by a 3-phase VFD. The VFD is located in the supply

fan section (030-050 units) or mixing box section (055-105

units) behind an access door. The VFD speed is controlled di-

rectly by the ComfortLink™ controls through a 4 to 20 mA

signal based on a supply duct pressure sensor. The VFD has a

display, which can be used for service diagnostics, but setup of

the building pressure and control loop factors should be done

through the scrolling marquee display. The VFD is powered

during normal operation to prevent condensation from forming

on the boards during the off mode and is stopped by driving the

speed to 0 (by sending a 4 mA signal to the VFD).

The Z Series units use ABB VFDs. The interface wiring for

the VFDs is shown in Fig. 31. Terminal designations are shown

in Table 94.

BOARD

NO.

TERMINAL

NUMBER

DESCRIPTION

TYPE

TB204 - FIELD CONNECTIONS (in Main Control Box)

TB204

Demand Limit Redline 24 vac out