Economi$Er X (Factory-Installed Option) - Carrier 48FC M20 Series Service And Maintenance Instructions

DCV MINIMUM AND MAXIMUM POSITION
To check the DCV minimum and maximum position:
1. Make sure EconoMi$er IV preparation procedure has been
performed.
2. Connect a 9-v battery to AQ (positive node) and AQ1 (neg-
ative node). The DCV LED should turn on. The actuator
should drive to between 90 and 95% open.
3. Turn the DCV Maximum Position potentiometer to midpoint.
The actuator should drive to between 20 and 80% open.
4. Turn the DCV Maximum Position potentiometer to fully
CCW. The actuator should drive fully closed.
5. Turn the Minimum Position potentiometer to mid-point.
The actuator should drive to between 20 and 80% open.
6. Turn the Minimum Position Potentiometer fully CW. The
actuator should drive fully open.
7. Remove the jumper from TR and N. The actuator should
drive fully closed.
8. Return EconoMi$er IV settings and wiring to normal after
completing troubleshooting.
SUPPLY-AIR SENSOR INPUT
To check supply-air sensor input:
1. Make sure EconoMi$er IV preparation procedure has been
performed.
2. Set the Enthalpy potentiometer to A. The Free Cool LED
turns on. The actuator should drive to between 20 and 80%
open.
3. Remove the 5.6 kilo-ohm resistor and jumper T to T1. The
actuator should drive fully open.
4. Remove the jumper across T and T1. The actuator should
drive fully closed.
5. Return EconoMi$er IV settings and wiring to normal after
completing troubleshooting.
ECONOMI$ER IV TROUBLESHOOTING COMPLETION
This procedure is used to return the EconoMi$er IV to opera-
tion. No troubleshooting or testing is done by performing the
following procedure.
1. Disconnect power at TR and TR1.
2. Set enthalpy potentiometer to previous setting.
3. Set DCV maximum position potentiometer to previous
setting.
4. Set minimum position, DCV set point, and exhaust poten-
tiometers to previous settings.
5. Remove 620-ohm resistor from terminals SR and +.
6. Remove 1.2 kilo-ohm checkout resistor from terminals SO
and +. If used, reconnect sensor from terminals SO and +.
7. Remove jumper from TR to N.
8. Remove jumper from TR to 1.
9. Remove 5.6 kilo-ohm resistor from T and T1. Reconnect
wires at T and T1.
10. Remove jumper from P to P1. Reconnect device at P and P1.
11. Apply power (24 vac) to terminals TR and TR1.

EconoMi$er X (Factory-Installed Option)

PRODUCT DESCRIPTION
The EconoMi$er ® X system is an expandable economizer control
system, which includes a W7220 economizer module (controller)
with an LCD and keypad (see Fig. 74). The W7220 module can be
configured with optional sensors.
Fig. 74 — W7220 Economizer Module
The W7220 economizer module can be used as a stand-alone
economizer module wired directly to a commercial set-back
space thermostat and sensors to provide outside air dry-bulb
economizer control.
The W7220 economizer module can be connected to optional
sensors for single or differential enthalpy control. The W7220
economizer module provides power and communications for
the sensors.
The W7220 economizer module automatically detects sensors by
polling to determine which sensors are present. If a sensor loses
communications after it has been detected, the W7220 economizer
controller indicates a device fail error on its LCD.
SYSTEM COMPONENTS
The EconoMi$er X system includes an economizer module, 20k
mixed air sensor, damper actuator, and either a 20k outdoor 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 inter-
face 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 pro-
vides 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 sensor can be added for Demand Controlled Ventilation
(DCV).
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