49
Step 12 — Install Accessories
Available accessories include:
• Roof Curb
• Thru-base connection kit (must be installed before unit is
set on curb)
• Manual outside air damper
• Two-Position motorized outside air damper
• EconoMi$er IV (with control and integrated barometric
relief)
• EconoMi$er2 (without control/for external signal and in-
tegrated barometric relief)
• Power Exhaust
• Differential dry-bulb sensor (EconoMi$er IV)
• Outdoor enthalpy sensor
• Differential enthalpy sensor
• Electric Heaters
• Single Point kits
• Low Ambient Controls
• Thermostat / Sensors
• CO
2
sensor
• DDC interface (PremierLink™ controller)
• Louvered hail guard
• Phase monitor control
• Winter Start kit
Refer to separate installation instructions for information
on installing these accessories.
Step 13 — Check Belt Tension
Measure the belt span length as shown in Fig. 59. Calcu-
late the required deflection by multiplying the belt span
length by
1
/
64
. For example, if the belt span length is 32 inch-
es: 32 x
1
/
64
=
1
/
2
inch deflection.
BELT FORCE — DEFLECTION METHOD
Check the belt tension with a spring-force belt force deflec-
tion gauge (available from drive belt manufacturer).
1. Place a straightedge along the belt between the two pul-
leys. Measure the distance between the motor shaft and
the blower shaft.
2. Set the tension gauge to the desired tension (see Table 1 in
Fig. 59). Place the large O-ring at that point.
3. Press the tension checker downward on the belt until the
large O-ring is at the bottom of the straightedge.
4. Adjust the belt tension as needed.
Adjust belt tension by loosing the motor mounting plate front
bolts and rear bolt (see Fig. 60) and slide the plate towards the
fan (to reduce tension) or away from the fan (to increase ten-
sion). Ensure the blower shaft and motor shaft are parallel to
each other (pulleys aligned). Tighten all bolts securely when fin-
ished.
BELT TENSION METHOD
Requires belt tension gauge that measures tension in belt in
units of lbs force.
Fig. 59 — V-Belt Force Label
Fig. 60 — Belt Drive Motor Mounting
UltraTech Compressor (50HC07 Units Only)
50HC07 (6 ton) units use a two-stage single UltraTech*
compressor. The UltraTech compressor’s molded plug should
be used at all times. The maximum power is 5A.
The compressor will modulate from part load to full load
when the voltage supplied to the molded plug is 18 to 28vdc
or 18 to 28 vac rectified to vdc. The compressor will modu-
late from full load to part load when the current in the circuit
drops below 0.9 MA. See Table 20 for additional details. For
service information, see 50HC04-14 Service and Mainte-
nance Instructions.
Table 1
Table 2
BELT
CROSS
SECTION
SMALLEST
SHEAVE
DIAMETER
BELT DEFLECTION FORCE (LBS)
UNNOTCHED
BELTS
NOTCHED BELTS
USED
NEW
USED
NEW
A, AX
3.0-3.6
3.7
5.5
4.1
6.1
3.8-4.8
4.5
6.8
5.0
7.4
5.0-7.0
5.4
8.0
5.7
8.4
B, BX
3.4-4.2
—
—
4.9
7.2
4.4-5.6
5.3
7.9
7.1
10.5
5.8-8.6
6.3
9.4
8.5
12.6
BELT CONDITION
TENSION FORCE IN BELT (LBS)
New
100
Used
80
BLOWER PULLEY
V-BELT
MOTOR
PULLEY
MOTOR
MOTOR MOUNTING
PLATE
MOUNTING
BOLTS (4)
* UltraTech is a trademark of Emerson Climate Technologies, Inc.
Summary of Contents for WeatherMaster 50HC*A07 Series
Page 4: ...4 Fig 2 Unit Dimensional Drawing Sizes 07 09 ...
Page 5: ...5 Fig 2 Unit Dimensional Drawing Sizes 07 09 cont ...
Page 6: ...6 Fig 3 Unit Dimensional Drawing Sizes 11 and 12 ...
Page 7: ...7 Fig 3 Unit Dimensional Drawing Sizes 11 and 12 cont ...
Page 25: ...25 Fig 42 Electro Mechanical Control Wiring Diagram ...
Page 26: ...26 Fig 43 Electro Mechanical Control Wiring Diagram with Humidi MiZer System ...
Page 27: ...27 Fig 44 Typical ComfortLink Control Wiring Diagram 50HC 08 09 shown ...
Page 29: ...29 Fig 46 Typical PremierLink Control Wiring Diagram ...
Page 30: ...30 Fig 47 Typical PremierLink Control Wiring Diagram with Humidi MiZer System Option ...
Page 31: ...31 Fig 48 Typical RTU Open Controller Wiring Diagram ...
Page 32: ...32 Fig 49 Typical RTU Open Controller Wiring Diagram with Humidi MiZer System Option ...
