Belt Force - Deflection Method; Belt Tension Method - Bryant 549J Series Installation Instructions Manual

Step 14 — Check Belt Tension
Measure the belt span length as shown in Fig. 52. Calculate the re-
quired deflection by multiplying the belt span length by
example, if the belt span length is 32 inches: 32 x
deflection.
BELT FORCE — DEFLECTION METHOD
Check the belt tension with a spring-force belt force deflection
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. 52). 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. 53) and slide the plate towards the fan
(to reduce tension) or away from the fan (to increase tension).
Ensure the blower shaft and motor shaft are parallel to each other
(pulleys aligned). Tighten all bolts securely when finished.

BELT TENSION METHOD

Requires belt tension gauge that measures tension in belt in units
of lbs force.
BELT DEFLECTION FORCE (LBS)
BELT SMALLEST
UNNOTCHED
CROSS SHEAVE
SECTION DIAMETER
USED
3.0-3.6 3.7
A, AX 3.8-4.8 4.5
5.0-7.0 5.4
3.4-4.2
B, BX 4.4-5.6 5.3
5.8-8.6 6.3
Table 1
BELT CONDITION TENSION FORCE IN BELT (LBS)
NEW
USED
Table 2
Fig. 52 — V-Belt Force Label
/ =
1
64
NOTCHED
BELTS BELTS
NEW USED NEW
5.5 4.1
6.8 5.0
8.0 5.7
— — 4.9
7.9 7.1 10.5
9.4 8.5 12.6
100
80
1 / . For
64
/ inch
1
2
MOUNTING
BOLTS (4)
Fig. 53 — Belt Drive Motor Mounting
Pre-Start and Start-Up
This completes the mechanical installation of the unit. Refer to the
unit's Service Manual for detailed Pre-Start and Start-Up instruc-
tions. Download the latest versions from HVAC Partners
(www.hvacpartners.com).
Typical Unit Piping
Each heat pump refrigeration system includes a compressor, accu-
mulator, reversing valve, dual-function outdoor coil with vapor
header check valve, cooling liquid line with a filter drier and a
check valve, dual-function indoor coil with a vapor header check
valve, and heating liquid line with a check valve and a strainer.
Unit sizes A04-06 have a single compressor-circuit. See Fig. 54
and Tables 17-19 for typical unit piping schematic. Dual-function
outdoor and indoor coils are designed to provide parallel coil cir-
cuits during evaporator-function operation and converging coil
circuits during the condenser-function operation.
6.1
7.4
8.4
7.2
43
BLOWER PULLEY
V-BELT
MOTOR
PULLEY
MOTOR
MOTOR MOUNTING
PLATE