9.Connect lead with fork terminal to corresponding points on terminal strip. Re.: C.Y.G. (See wiring diagram.)
10.Wire nut leads with 5/8" stripped ends to Y1 and Y2 leads from thermostat. See wiring diagram in this manual or on economizer.
NOTE: Wires referenced in Note 1 on wiring diagram are for special control application only and are not normally used. These wires may be used in conjunction with other circuitry to open the damper regardless of outside temperature and humidity. Consult factory for details.
11.Close control panel cover
12.Reinstall the blower access panel at top of unit and secure with sheet metal screws.
13.Replace filter bracket, filter and four (4) screws in front condenser grille.
14.ECONOMIZER CHECK OUT
A.Remove mist eliminator (Figure 3). Locate the minimum position potentiometer. (See Figure 5.)
B.Energize the evaporator blower by switching thermostat to the manual fan position with heat /cool in the OFF position.
C.Cycle the minimum position potentiometer (factoryset for 0% fresh air) 0 to full open. (See Figure 5.) Throughout checkout procedure observe operation of damper to insure there is free, unobstructed operation through the entire angle of damper travel. Then adjust the damper minimum open position to meet local codes or application requirements. See example below.
EXAMPLE:
1.Measure return air temperature (RAT) (assume 75°F for example).
2.Measure outdoor air temperature (OAT) (assume 60°F for example).
3.Calculate the mixed air temperature (MAT) which will result from the desired combination of OAT (10 percent) and RAT (90 percent).
.1 OAT + .9 RAT = MAT
5.Mark correct setting on dial of minimum position potentiometer for future reference.
D.Adjust the enthalpy control to position A, B, C, or D to achieve the maximum combination of temperature and humidity acceptable for the installation as per Table 2 below. The suggested setting is between A & B 70° DB @ 55 percent RH. Further recommendation is to always set the control at C or above. (See Figure 5.)
E.Switch the thermostat fan control to automatic, and position the heat cool switch to cool. Adjust the thermostat temperature to engage the first stage of cooling only (Y). This will cause the dampers to modulate to achieve mixed air temperature of 55° provided outside air enthalpy is sufficiently low. If enthalpy is too high for economizing, low enthalpy can be simulated by temporarily removing and jumping leads on terminal 2 and 3 of enthalpy control together. This will also cause the economizer damper to modulate away from minimum position. (Be sure to properly reconnect leads at end of checkout procedure.)
F.Readjust temperature on the thermostat to engage the second stage of cooling (Y2). The damper motor should return to previously set minimum position. Compressor motor should start.
G.Switch thermostat to OFF fan and OFF heat/ cool positions to
15.Replace control access panel and mist eliminator.
16.Remove blank off plate or barometric fresh air damper if installed on the service access panel. Plug the four (4) holes used to mount the BOP or BFAD with the plastic plugs supplied with the economizer.
16.Replace service access panel.
17.Economizer is now ready for operation.
or substituting example values |
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| TABLE 2 |
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| ENTHALPY CONTROL SETTING |
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.1 (60° F) + .9 (75° F) = 73.75° F |
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Dial |
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4. Adjust the minimum |
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| Setting | 20% RH | 50% RH |
| 80% RH | ||
position potentiometer |
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knob until proper mixed air |
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| A | 80 deg .F | 73 deg. F |
| 66 deg. F |
temperature, as calculated |
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| (26 deg. C) | (23 deg. C) |
| (19 deg.C) | |
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above, is reached. Care |
| Enthalpy | B | 76 deg. F | 70 deg. F |
| 63 deg. F |
should be taken to insure |
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| (24 deg. C) | (21 deg. C) |
| (17 deg. C) | |||
thermometer is sensing |
| Control |
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| 74 deg. F | 66 deg. F |
| 59 deg. F | |||
air that is well mixed. |
| Setting | C |
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| (23 deg. C) | (19 deg. C) |
| (15 deg. C) | ||
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| D | 71 deg. F | 63 deg. F |
| 54 deg. F |
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| (21 deg. C) | (17 deg. C) |
| (12 deg. C) | |
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| Page | 9 of 13 | |
