System Components; Specifications - Carrier WeatherExpert 50LC 07 Series Installation Instructions Manual

OF SPEED
Fig. 44 — Outdoor Fan Speed Select Switch
JUMPER ON
PS
TS
Fig. 45 — Schematic of SPST Low Ambient Switch
Table 5 shows the operation of the outdoor fan for size 07 units.
Table 5 — Low Ambient Temperature Outdoor Fan
Control
NO. OF NO. OF
LC SIZE
FANS ON FANS OFF
07 2 0
Heating
In the Heating Mode (W1 on the thermostat), power is applied
to the G and W1 terminal at the ISC board and energizes the
first state of electric heat. Upon more call for heat (W2 at the
thermostat), power is applied to the G and W2 terminal at the
ISC board and energizes the second state of electric heat. The
VFD controlled indoor fan will operate at high speed regard-
less of the heating demand.
®
EconoMi$er X (Factory Option)
The EconoMi$er X system is an expandable economizer con-
trol system, which includes a W7220 economizer module (con-
troller) with an LCD and keypad (see Fig. 46). The W7220 can
be configured with optional sensors.
SELECT
ON
FCS
MIN
OFF
PS
OF
LAS
SPST
OUTDOOR
FAN
SWITCH
SELECT
SWITCH
SPST Up
Fig. 46 — W7220 Economizer Module
The W7220 economizer module can be used as a stand-alone
economizer module wired directly to a commercial set-back
space thermostat and sensors to provide outside air dry-bulb
economizer control.
The W7220 economizer module can be connected to optional
sensors for single or differential enthalpy control. The W7220
economizer module provides power and communications for
the sensors.
The W7220 economizer module automatically detects sensors
by polling to determine which sensors are present. If a sensor
loses communications after it has been detected, the W7220
economizer controller indicates a device fail error on its LCD.

SYSTEM COMPONENTS

RPM
The EconoMi$er X system includes an economizer module,
20k mixed air sensor, damper actuator, and either a 20k out-
250 door air temperature sensor or S-Bus enthalpy sensors.
Economizer Module
The module is the core of the EconoMi$er X system. The
module is mounted in the unit's control box, and includes the
user interface for the system. The W7220 economizer module
provides the basic inputs and outputs to provide simple
economizer control. When used with the optional sensors, the
economizer module provides more advanced economizer
functionality.
S-Bus Enthalpy Control Sensors
The sensor is a combination temperature and humidity sensor
which is powered by and communicates on the S-Bus. Up to
three sensors may be configured with the W7220 economizer
module.
CO Sensor (optional)
2
The CO sensor can be added for Demand Controlled Ventila-
2
tion (DCV).

SPECIFICATIONS

W7220 Economizer Module
The module is designed for use with 2 to 10 vdc or bus com-
municating actuator. The module includes terminals for CO
sensor, Mixed Air sensor, and an Outdoor Dry Bulb sensor. En-
thalpy and other options are available with bus sensors.
User Interface
Provides status for normal operation, setup parameters, check-
out tests, and alarm and error conditions with a 2-line 16 char-
acter LCD display and four button keypad.
Electrical
• Rated Voltage — 20 to 30 vac RMS, 50/60 Hz
• Transformer — 100 va maximum system input
28
2