Manual 2100-695
Page
22 of 54
6. Press UP or DOWN keys to change to the desired
value.
7. Press ENTER key to save the value.
Filters
The unit is equipped with two (2) 20" x 30" x 2" MERV
8 filters. The filters slide into position making them easy
to service. The filters can be serviced from the outside
by removing either the right or left filter access panel.
Dirty Filter Switch
These units are equipped with a differential pressure
switch to indicate when the filter(s) needs to be
replaced (see Figure 32). The dirty filter switch
measures the pressure difference across the filter
through silicone tubing routed to the blower and vent
areas of the unit.
The switch circuit consists of a
normally open
filter
pressure switch. The switch will open when the
pressure differential goes above the setting indicated
on the dial. When the pressure difference returns below
the setting on the dial, the switch will close.
Adjustment of dirty filter switch may be necessary to
ensure proper operation. See Table 8 and Figure 35 to
aid in setting the filter switch to operate at different
percentages of filter blockage.
Dirty Filter Alarm
The wall-mount unit is equipped with a differential
pressure switch input to the controller (see Figure 32).
When the switch indicates a dirty filter, the controller
will generate an alarm. Once the condition is no longer
present, the alarm will automatically clear. Additionally,
an indicator light will be turned on with the alarm and
turned off when the alarm clears (see Figure 35).
Disabling the dirty filter switch in
I/O Config
disables
this alarm.
The threshold of this alarm is adjusted by changing the
settings on the switch (see Table 8).
Filter Indicator Light
These units are equipped with a 24v indicator light
mounted on side of unit that displays the current status
of the filter (see Figure 35). When the light is on, the
AIRSTREAM BEFORE FILTER
TUBE LOCATED IN
COVER
REMOVE COVER
SCREW TO
TUBE LOCATED IN
AIRSTREAM AFTER FILTER
MIS-3901
ADJUSTMENT
INDICATOR ARROW
ADJUSTMENT
KNOB
FILTER
LIGHT
FIGURE 35
Dirty Filter Switch and Filter Indicator Light
MIS-3901
