increase in cooling capacity causes the mixed-air temperature
to drop below 45 E then the outdoor-air damper position will
be decreased to the minimum position. If the mixed-air temper-
ature continues to fall, the outdoor-air damper will close. Con-
trol returns to normal once the mixed-air temperature rises
above 48 E
If optional power exhaust is installed, as the outdoor-air
damper opens and closes, the power exhaust fans will be ener-
gized and deenergized if the position goes above or below the
power exhaust set point. When the exhaust fan is required to be
on, the LED on the control will be energized.
If field-inst_dled accessory CO2 sensors am connected to the
EconoMi$er IV control, a demand controlled ventihttion strate-
gy will begin to operate. As the CO2 level in the zone increases
above the CO2 set point, the minimum position of the damper
will be incmased proportionally from the minimum damper po-
sition to the maximum demand ventihttion damper position. As
the CO2 level decmases because of the increase in fmsh ail: the
outdoor-air damper will be proportiomflly closed.
If them is no G signal then the control will drive the damper
to the fully closed position.
The control is also equipped with an occupied/unoccupied
input. If the input is closed, then the damper will be cMven to
the minimum position when G is energized. If the input is open
then the damper will remain in the fully closed position unless
them is a demand for flee cooling of DCV ventihttion.
On the initial power to the EconoMi$er [V control, it will
take the damper up to 2_/2 minutes befom it begins to position
itself. Any change in damper position will take up to 30 sec-
onds to initiate. Damper movement fiom full closed to full
open (or vice vel_a) will take between 11/2and 21/2 minutes.
If fiee cooling can be used as determined fiom the appropri-
ate changeover command (switch, dly bulb, enthalpy curve.
differential dU bulb, or differential enthalpy), then the control
will moduhtte the dampel_ open to maintain the mixed-tdr tem-
peratum set point at 50 to 55 E
If there is a further demand for cooling (cooling second
stage -- Y2 is energized), then the control will bring on com-
pressor stage 1 to maintain the mixed-air temperature set point.
The EconoMi$er IV damper will be open at maximum
position. EconoMi$er IV operation is limited to a single
compressor.
HEATING. UNITS WITH ECONOMISER IV -- When the
room temperature calls for heat, the heating controls am ener-
gized as described in the Heating, Units Without Economizer
section. The IFM is energized _md the EconoMiSer IV damper
modulates to the minimum position. When the thermostat is
satisfied, the dmnper modulates closed.
Table 5 -- Fan Performance -- 48PGF/N03 Vertical Units
AIRFLOW
(Cfm)
AVAILABLE EXTERNAL STATIC PRESSURE (in. wg)
0.4 0.6 0.80.2 1.0
Rpm Bhp Rpm Bhp Rpm Bhp Rpm Bhp Rpm Bhp
600 407 0.05 551 0.10 683 0.15 759 0.21 843 0.27
680 413 0.08 555 0.11 687 0.17 783 0.22 847 0.29
700 419 0.08 580 0.12 671 0.18 786 0.24 851 0.30
750 425 0.07 585 0.13 676 0.19 770 0.25 854 0.32
800 433 0.08 570 0.14 680 0.20 774 0.27 858 0.34
880 440 0.08 575 0.15 685 0.22 779 0.29 862 0.36
900 448 0.09 581 0.16 690 0.23 783 0.30 866 0.38
950 458 0.10 587 0.17 695 0.24 788 0.32 871 0.40
1000 465 0.11 594 0.18 700 0.26 792 0.34 875 0.42
AVAILABLE EXTERNAL STATIC PRESSURE (in. wg)
1.4 1.6
AIRFLOW
(Cfm)
6O0
650
7O0
750
8O0
850
9O0
950
1000
1.2
Rpm Bhp Rpm
920 0.33 990
923 0.35 994
927 0.37 997
931 0.39 1001
934 0.41 1004
938 0.44 1008
942 0.48 1012
948 0.48 1018
950 0.51 1020
Bhp
0.40
0.42
0.44
0.47
0.49
0.52
0.54
0.57
0.59
Rpm Bhp Rpm
1058 0.47 1117
1059 0.49 1121
1063 0.52 1124
1088 0.54 1128
1070 0.57 1131
1073 0.80 1135
1077 0.83 1138
1081 0.85 1142
1085 0.88 1146
1.8
Bhp
0.54
0.57
0.60
0.62
0.65
0.68
0.71
0.74
0.78
2.0
Bpm
1176
1179
1182
1186
1189
1193
1196
1200
1204
Bhp
0.62
0.65
0.68
0.71
0.74
0.77
0.80
0.83
0.87
Bhp --
LEGEND
Brake Horsepower
Field-Supplied Motor Required
NOTES:
1. Motor drive range is 482 to 738 rpm for low range motor/drive and 858 to
1001 rpm for high range motor/drive. All other rpms require a field-supplied
drive.
2. Maximum continuous bhp is 0.85 for low range motor/drive and 0.85 for high
range motor/drive.
3. See page 35 for General Fan Performance Notes.
22
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