Manual 2100-695C
Page
22 of 56
Blower Status Switch
The unit is equipped with a differential pressure airflow
switch to monitor the blower (see Figure 32). If the
blower is turned on and the switch doesn't close to
indicate there is differential pressure between the inlet
and outlet of the blower, an alarm will be generated.
For switch settings, see Figure 32.
Differential airflow status can be viewed by:
1. Press MENU key to go to the Main Menu screen.
2. Press UP or DOWN keys and ENTER key to enter
TECHNICIAN password 1313.
3. Press UP or DOWN keys to scroll to
I/O Config
;
press ENTER key.
4. Press UP or DOWN keys to scroll to
Digital In
Config C1
.
5. Reference
7
NoAir
row and
Val
column (see Figure
33).
Blower Status Alarm
If the blower is commanded on and the fan status
switch (differential pressure) has not indicated the fan
is running within 45 seconds, the system will generate
an alarm.
Disabling the blower status switch in
I/O Config
disables this alarm.
This alarm is just a notification and will clear itself
when the conditions are no longer present.
To adjust the air flow alarm delay:
1. Press MENU key to go to the Main Menu screen.
2. Press UP or DOWN keys and ENTER key to enter
USER password 2000.
3. Press UP or DOWN keys to scroll to
System Config
;
press ENTER key.
4. Press UP or DOWN keys to scroll to
Alarm Setup A8
.
5. Press ENTER key to scroll to
Air Flow Alarm Del
(see Figure 34).
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.
FIGURE 33
Verifying Differential Airflow Status
FIGURE 32
Dirty Filter Switch and Blower Status Switch
(Set per Table 9)
Blower Status
Switch
(WR35 set @ 0.12,
WR36 set @ 0.12,
WR58 set @ 0.20)
FIGURE 34
Adjusting Air Flow Alarm Delay
