RT-SVX50C-EN
25
Maintenance
Make sure all personnel are standing clear of the unit
before proceeding. The system components will start
when the power is applied.
Fan Belt Adjustment—Belt Drive
Units
The fan belts must be inspected periodically to assure
proper unit operation.
Replacement is necessary if the belts appear frayed or
worn. Units with dual belts require a matched set of belts
to ensure equal belt length.
When removing or installing the new belts, do not stretch
them over the sheaves. Loosen the belts using the belt
tension adjustment bolts on the motor mounting base.
Once the new belts are installed, using a Browning or
Gates tension gauge (or equivalent) illustrated in
Figure 17
; adjust the belt tension as follows;
1.
To determine the appropriate belt deflection;
a. Measure the center-to-center shaft distance (in
inches) between the fan and motor sheaves.
b. Divide the distance measured in
Step 1a
by 64; the
resulting value represents the amount of belt
deflection that corresponds to the proper belt
tension.
2. Set the large O-ring on the belt tension gauge at the
deflection value determined in
Step 1b
.
3. Set the small O-ring at zero on the force scale of the
gauge plunger.
4. Place the large end of the gauge at the center of the belt
span; then depress the gauge plunger until the large
O-ring is even with the top of the next belt or even with
a straightedge placed across the fan and motor
sheaves.
Refer to
Table 5, p. 25
.
5. Remove the belt tension gauge. The small O-ring now
indicates a number other than zero on the plunger’s
force scale. This number represents the force (in
pounds) required to give the needed deflection.
6. Compare the “force” scale reading (
Step 5
) with the
appropriate “force” value listed in
Table 5, p. 25
. If the
“force” reading is outside the range, readjust the belt
tension.
Note:
Actual belt deflection “force” must not exceed the
maximum “force” value shown in
Table 5, p. 25
.
7.
Recheck the belt tension at least twice during the first
2 to 3 days of operation. Belt tension may decrease
until the new belts are “run in”.
WARNING
Rotating Components!
The following procedure involves working with rotating
components. Disconnect all electric power, including
remote disconnects before servicing. Follow proper
lockout/tagout procedures to ensure the power can not
be inadvertently energized. Failure to disconnect power
before servicing could result in rotating components
cutting and slashing technician which could result in
death or serious injury.
Figure 17.
Belt tension gauge
Table 5.
Belt tension measurement and deflection
ranges
Belts
Cross
Section
Small P.D
Range
(in.)
Deflection Force (lb)
Super
Gripbelts
(in.)
Gripnotch
(in.)
Steel Cable
Gripbelts
(in.)
Min. Max.
Min.
Max
Min. Max.
A
3.0–3.6
3
4 1/2 3 7/8
5 1/2 3 1/4
4
3.8–4.8
3 1/2
5
4 1/2
6 1/4 3 3/4
4 3/4
5.0–7.0
4
5 1/2
5
6 7/8 4 1/4
5 1/4
B
3.4–4.2
4
5 1/2 5 3/4
8
4 1/2
5 1/2
4.4–5.6
5 1/8 7 1/8
6 1/2 9 1/8 5 3/4
7 1/4
5.8–8.8
6 3/8 8 3/4
7 3/8 10 1/8
7
8 3/4
Belts
Cross
Section
Small P.D
Range
(mm)
Deflection Force (kg)
Super
Gripbelts
(mm)
Gripnotch
(mm)
Steel Cable
Gripbelts
(mm)
Min. Max. Min.
Max. Min. Max
A
13.3–16.0
13.3
20.0
17.2
24.5
14.5
17.8
16.9–21.4 15.6
22.2
20.0
27.8
16.7
21.1
22.0–31.1
17.8
24.5
22.2
30.6
18.9
23.4
B
15.1–18.7
17.8
24.5
25.6
35.6
20.0
24.5
19.6–24.9
22.8
31.7
28.9
40.6
25.6
32.3
25.8–39.1 28.4
38.9
32.8
45.0
31.1
38.9
