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Table 7 — CO
2
Sensor* Standard Settings
LEGEND
*Available sensor part numbers are listed in Table 4.
IX. STEP 9 — ADJUST EVAPORATOR-FAN SPEED
Adjust evaporator-fan speed to meet jobsite requirement.
Table 8 shows fan rpm at motor pulley settings and Table 9
shows motor efficiencies. Table 10 shows motor performance.
Refer to Fan Performance Tables 11-30 to determine fan
speed settings. Fan motor pulleys are factory set for speed
shown in Tables 1A and 1B.
To change fan speed:
1. Shut off unit power supply and install lockout tag.
2. Loosen belt by loosening fan motor mounting plate
nuts (see Fig. 33 and 34).
3. Loosen movable pulley flange setscrew (see Fig. 35).
4. Screw movable flange toward fixed flange to increase
fan speed and away from fixed flange to decrease fan
speed. Increasing fan speed increases load on motor.
Do not exceed maximum speed specified in Tables 1A
and 1B.
5. Set movable flange at nearest flat of pulley hub and
tighten setscrew (see Tables 1A and 1B for speed
change for each full turn of pulley flange).
To align fan and motor pulleys:
1. Loosen fan pulley setscrews.
2. Slide fan pulley along fan shaft.
3. Make angular alignment by loosening motor from
mounting plate.
To adjust belt tension (see Fig. 33 and 34):
1. Loosen fan motor mounting plate nuts.
2. Units 090-103 — Slide motor mounting plate away
from fan scroll for proper belt tension (
1
/
2
-in.
deflection with 5 to 10 lb of force) and tighten mount-
ing nuts (see Fig. 33).
Units 120-151 — Slide motor mounting plate down-
ward to tighten belt tension. (
1
/
2
-in. deflection with
5 to 10 lb of force.) Secure motor mounting plate nuts.
See Fig. 34.
3. Adjust bolt and nut on mounting plate to secure
motor in fixed position.
Realign fan and motor pulleys:
1. Loosen fan pulley setscrews.
2. Slide fan pulley along fan shaft.
3. Make angular alignment by loosening motor from
mounting plate.
SETTING EQUIPMENT OUTPUT
VENTILATION
RATE
(cfm/Person)
ANALOG
OUTPUT
CO
2
CONTROL
RANGE (ppm)
OPTIONAL
RELAY SETPOINT
(ppm)
RELAY
HYSTERESIS
(ppm)
1
Interface with Standard
Building Control System
Proportional Any 4-20 mA 0-2000 1000 50
2 Proportional Any 7-20 mA 0-2000 1000 50
3 Exponential Any 4-20 mA 0-2000 1100 50
4
Economizer
Proportional 15 4-20 mA 0-1100 1100 50
5 Proportional 20 4-20 mA 0- 900 900 50
6 Exponential 15 4-20 mA 0-1100 1100 50
7 Exponential 20 4-20 mA 0- 900 900 50
8 Health & Safety Proportional — 4-20 mA 0-9999 5000 500
9 Parking/Air Intakes/ Loading Docks Proportional — 4-20 mA 0-2000 700 50
ppm — Parts Per Million
MOTOR MOUNTING
PLATE NUTS
Fig. 33 — Typical Belt-Drive Motor Mounting
for Sizes 090-103