Dirty Filter Switch; Dirty Filter Switch Adjustment; Figure 16 Dirty Filter Switch Location - Bard 11EER WA W18AB-A User's Application Manual

Dirty Filter Switch

1. Disconnect all power to the unit. Remove control
panel outer cover and upper front panel.
2. The dirty filter switch is located on top of the
filter partition to the right of the blower wheels on
W**AB units and to the left of the blower wheels
on W**LB units (see Figure 16). The dirty filter
indicator light and reset switch is attached to the
side of the control panel on the right side of the
filter access opening on W**AB units and on the
left side of the filter access opening on W**LB
units. Remove the cover on the dirty filter switch
and ensure the knob is set at 0.4" W.C. (see Figure
17). This is only a recommended starting point
prior to making switch adjustments. Switch setting
is highly dependent on filter type used, blower
speed, unit ducting and other unit installation
characteristics. See Dirty Filter Switch Adjustment
for instructions on how to make proper switch
adjustments.
3. Re-install upper front panel.
W**LB Units
Manual 2100-689H
Page 34 of 42

Dirty Filter Switch Adjustment

1. Apply power to the unit.
2. Turn the unit indoor blower on (energize R-G on
low voltage terminal board).
3. With air filters installed and switch initially set
at 0.4" W.C. (see Step 2 under Dirty Filter
Switch), begin restricting the air filter of the unit
using a piece of cardboard under the filters until
the switch trips and the light comes on. If the
filter is restricted by 75% (or desired restriction
amount), skip to Step 6.
4. If switch setting adjustment is required,
disconnect power to the unit. Remove the upper
front panel and the cover on the airflow switch so
that adjustment can be made. If the switch tripped
before 75% restriction was reached, turn the knob
slightly clockwise. If the switch tripped after 75%,
turn the knob counter-clockwise (see Figure 17).
5. Replace the upper front panel and repeat Steps
1-3. Continue to make adjustments described in
Step 4 until the desired restriction is obtained.
6. Remove the restriction and reset the filter switch.
Replace the switch cover once adjustment is
complete.
7. Install the outer control panel cover. This
completes the adjustment.
FIGURE 16
Dirty Filter Switch Location
W**AB Units