Carrier 50HCQA04-06, Installation Instructions Manual

42

Fig. 50 — Single Enthalpy Curve Boundaries

Checkout

Inspect all wiring connections at the economizer module’s ter-

minals, and verify compliance with the installation wiring dia-

grams. For checkout, review the Status of each configured pa-

rameter and perform the Checkout tests.
NOTE: For information about menu navigation and use of the

keypad see Interface Overview on page 33.

Power Up
 After the W7220 module is mounted and wired, apply power.
Initial Menu Display
 On initial start up, Honeywell displays on the first line and

economizer W7220 on the second line. After a brief pause, the

revision of the software appears on the first line and the second

line is blank.
Power Loss (Outage or Brownout)
 All setpoints and advanced settings are restored after any pow-

er loss or interruption.
NOTE: All settings are stored in non-volatile flash memory.
Status
 Use the Status menu (see Table 10) to check the parameter val-

ues for the various devices and sensors configured.
NOTE: For information about menu navigation and use of the

keypad see Interface Overview on page 33.
Checkout Tests
 Use the Checkout menu (see page 38) to test the damper oper-

ation and any configured outputs. Only items that are config-

ured are shown in the Checkout menu.

NOTE: For information about menu navigation and use of the

keypad see Interface Overview on page 33.
To perform a Checkout test:
1. Scroll to the desired test in the Checkout menu using the

▲

 and 

▼

 buttons. 

2. Press the 

 (Enter) button to select the item. RUN?

appears. 

3. Press the 

 (Enter) button to start the test. The unit

pauses and then displays IN PROGRESS. When the test is

complete, DONE appears. 

4. When all desired parameters have been tested, press the 

(Menu Up/Exit) button to end the test.

The Checkout tests can all be performed at the time of installa-

tion or at any time during the operation of the system as a test

that the system is operable.

Troubleshooting

Alarms 
The economizer module provides alarm messages that display

on the 2-line LCD.
NOTE: Upon power up, the module waits 60 minutes before

checking for alarms. This allows time for all the configured devic-

es (e.g. sensors, actuator) to become operational. The exception is

the SAT sensor which will alarm immediately.
If one or more alarms are present and there has been no keypad

activity for at least 5 minutes, the Alarms menu displays and

cycles through the active alarms.
You can also navigate to the Alarms menu at any time.
Clearing Alarms
 Once the alarm has been identified and the cause has been re-

moved (e.g. replaced faulty sensor) the alarm can be cleared

from the display.
To clear an alarm, perform the following:
1. Navigate to the desired alarm.
2. Press the 

 (Enter) button. ERASE? displays.

3. Press the 

 (Enter) button. ALARM ERASED displays.

ECONOMIZING

AVAILABLE

NOT AVAILABLE

ENTHALPY

RA

 HUM (%RH)

RA

 TEMP

TEMPERATURE

ABSOLUTE HUMIDITY

ES5

ES4

ES3

ES2

ES1

HL

P1
(T,RH)

P2 (T,RH)

SINGLE ENTHALPY

DUAL ENTHALPY

HIGH LIMIT

WARNING

Failure to follow this warning could result in personal

injury, property damage, or death. 
Before performing service or maintenance operations on

unit, always turn off main power switch to unit and in-

stall lock(s) and lockout tag(s). Unit may have more than

one power switch. Ensure electrical service to rooftop

unit agrees with voltage an amperage listed on the unit

rating plate.
If any wiring changes are required, first be sure to re-

move power from the Economizer module before start-

ing work. Pay particular attention to verifying the power

connection (24 Vac).

CAUTION

Failure to follow this caution may result in damage to

equipment. Be sure to allow enough time for compressor

startup and shutdown between checkout tests so that you

do not short-cycle the compressors.