Control Center Jumper Settings - Lennox Harmony II Zone Control System Installation Instructions Manual

Control Center Jumper Settings

®
The Lennox Harmony II control center is designed to ac-
commodate a wide variety of applications. Some set−up is
required to allow the control center to perform in a specific
application. (Only qualified technicians should perform
equipment set−ups.) The control center contains nine
jumper blocks in six areas on the circuit board. The position
of these jumpers determines how the system will function.
See figure 8. The small plastic covered jumpers are in
place when the control is shipped.
To change jumper positions, gently pull the jumper off the
pins and place it on the desired set of pins. If the jumpers
are changed while the equipment is operating, DIAG 2 will
flash and the new operation will immediately take effect. If
the jumper is not needed, it may be stored by placing it on
one pin only so that electrical contact cannot be made. See
figure 9.
Storing Jumpers
STORE JUMPER BY PLACING
IT ON ONE PIN SO THAT
ELECTRICAL CONTACT
CANNOT BE MADE.
Figure 9
Additional jumpers are available from Lennox as part
#38L94.
CAUTION
Discharge static electricity before touching the Har-
®
mony II control center. Static electrical discharge
will damage electronics.
CFM Air Selection Jumpers
The zone control system allows the user to select the ap-
propriate air volume for each zone. The user must select air
volumes for at least zone 1 and one other zone. Unused
zones must have their air selection jumper placed on the OFF
pins. See figure 10. The range of jumper settings is from 25%
to 95%.
JUMPER
PINS
Page 15
AIR SELECTION JUMPER PINS
AIR SELECTION
(located on system control center)
25%
35%
45% Pin shown with jumper on 35%.
55%
65%
75%
Pin shown with jumper on 25%.
85%
95%
OFF
25%
Place jumper on pins that correspond
35%
with the desired CFM.
45%
55%
65%
75%
85%
95%
NOTE−Only zones 2 through 4 have an OFF setting.
Figure 10
To Determine Air Selection Jumper Settings:
1. Use a cooling load analysis to determine the required
CFM for each zone.
2. Determine the minimum CFM for the indoor unit. To
find the CFM, compare the jumper settings on the
unit's blower control board with the specific furnace or
blower coil blower chart.
3. Calculate the pulse width modulation multiplier (PWM)
using the two values from step 1 and 2:
Formula
PWM Multiplier
4. Go to figure 11. On the vertical axis, find the PWM you
calculated in step 3. Proceed horizontally to the 0% re-
duction (cooling) line, then down vertically to the hori-
zontal axis. Read the percent air.
5. Set the air selection jumper pin for the zone using the
percent air determined in step 4. If the percent air falls
between available jumper settings, select the next
highest setting.
6. Repeat steps 1−5 for each zone.
Example − 1 Given that maximum CFM is 2220 and
minimum CFM is 720, and Zone 1 requires 1020 CFM,
find the total % air for zone 1.
Formula
PWM Multiplier
Solution
PWM Multiplier
In figure 11, example 1, enter the vertical axis at 0.2,
proceed horizontally to the 0% reduction (cooling) line,
then go vertically down to the horizontal axis and read
40% of air. Since there is no 40% jumper setting, go to
the next higher setting. Then, 45% will be the air selec-
tion jumper setting for this zone. Repeat the calcula-
tion above for all zones to determine each zones multi-
plier.
= (Req'd CFM − Min. CFM)
(Max CFM − Min. CFM)
= (Req'd CFM − Min. CFM)
(Max CFM − Min. CFM)
= (1020−720) =
(2220−720)
0.2