Operation
Setting the economizer or 0-50% motorized hood (option)
The ECA board is mounted on the damper actuator. To access the ECA board on economizers:
•Remove the access panel located on the economizer section.
•The electrical power must be disconnected to set the minimum position and check the economizer.
•Disconnect the power supply, put the thermostat fan selector to "ON" and the "HEAT/COOL" selector to "OFF". This puts the damper in the minimum ventilation position.
•To set the required minimum ventilation air position, turn the dial on the ECA clockwise to increase ventilation, or anti- clockwise to decrease ventilation. The damper will open at this setting whenever the fan circuit is powered up.
•When the arrow on the dial adjustment screw is pointing to 8 o'clock, the minimum position is roughly 0%. When the dial is pointing to 12 o'clock it is roughly 25%, and when the dial is pointing to 4 o'clock it is roughly 50%
To check the damper is functioning correctly, the ECA is equipped with an indicator light in the middle of the board. This light operates as in Table 35.
Table 35 - ECA board LED
OFF: | No Power or Failure | |
ON: | Normal, OK to Economize | |
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| |
Slow Flash: | Normal, Not OK to | |
|
| Economize |
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| |
Fast Flash: | Communications Failure | |
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| |
Pulse Flash: | Error Code: | |
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|
|
1 | Flash: | Actuator Fault |
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|
|
2 | Flashes: | C02 Sensor |
3 | Flashes: | RA Humidity Sensor |
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|
|
4 | Flashes | RATemp Sensor |
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|
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5 | Flashes: | OA Quality Sensor |
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|
|
6 | Flashes: | OA Humidity Sensor |
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7 | Flashes: | OATernp Sensor |
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|
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8 | Flashes: | MATemp Sensor |
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|
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9 | Flashes: | RAM Fault |
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| |
10 Flashes: | ROM Fault | |
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| |
11 Flashes: | EEPROM Fault | |
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|
|
While setting the minimum position the damper may move toward the new setting in several small steps. Once the damper has remained in the same position for 10 to
15 seconds it can be assumed it is in the new position.
47 |
