JOHNSON CONTROLS
71
SECTION 3 - MAINTENANCE
FORM 102.20-OM2
ISSUE DATE: 6/01/2015
3
Adjusting Air Seals
The seals are designed to be durable and require no
maintenance other than adjustment. But, if the seals
become worn or damaged, replace them. Clip the seals
to the cassette or post metal.
Inspect Wheel Drive Components
Bearings
- Small wheels are equipped with no main-
tenance inboard bearings, which should require no
maintenance during the life of the AHU. Larger wheels
come equipped with an external flanged bearing, which
should be greased annually with a petroleum-based lu-
bricant.
Drive Motor
- The drive motors should require no
maintenance. If the motor needs to be replaced, Re-
placement motors may be purchased from normal mo-
tor distributors.
Drive Belts
- Wheel belts are multi-link belts with in-
dividual links constructed of a high performance poly-
urethane elastomer, which is reinforced with multiple
plies of polyester fabric. This belt provides strong, yet
flexible belting. The multi-link feature provides quick,
easy servicing or replacement.
How to Measure, Assemble and Install
How to Measure -
Pull belt tight around pulleys to
check hand tight length, overlapping the last two tabs
with two holes in matching links as shown. Count the
number of links and remove one link for every 24 of
3L, Z/10, A/4L and B/5L sections, and one link for
every 20 of C and D sections. This gives the correct
installed belt length and will ensure optimum belt ten-
sion when running.
LD17099
FIGURE 71 -
HOW TO MEASURE
Every tenth link is designated with an ar-
row (
g
) (3L, Z/10, A/4L and B/5L only).
For multiple belt drives, ensure that each
belt has the same number of links.
IMPORTANT
- Turn belt INSIDE OUT (as shown) to
ensure easy assembly and disassembly.
Disassembly
A. Hold belt upside down. Bend back as far as pos-
sible; hold with one hand. Twist one tab 90° paral-
lel with slot.
B. Pull end of link over tab.
C. Rotate belt end with tab 90°.
D. Pull belt end through two links.
FIGURE 72 -
DISASSEMBLY
LD17100
Assembly
A. Hold belt with tabs pointing outward.
B. Place end tab through two links at once.
C. Flex belt further and insert second tab through end
link by twisting tab with thumb.
D. Ensure tab returns to position across belt. Reverse
belt so tabs run inside.
FIGURE 73 -
ASSEMBLY
LD17101
Installation
1. Turn belt with tabs to the inside before installing.
2. Determine direction of drive rotation.
3. Belt must travel with tabs trailing or following the
belt direction arrow (
g
).
4. Fit belt in nearest groove of smaller pulley.
5. Roll belt onto larger pulley, turning the drive
slowly. Belt may seem very tight; this is ok; DO
NOT JOG MOTOR.
6. Check to see all tabs are still in their correct posi-
tion and are not twisted out of alignment.
7. For multiple belt drives, work belt from groove
to groove. On particularly wide drives, it may be
easier to install half the belts from the inboard side
and half from the outboard.
