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FIGURE 11
Measuring Pressure Differential
1 − Remove thermostat demand and allow unit to
cycle off.
2 − Install a tee in the negative (−) line (red tubing) and a
tee in the positive (+) line (black tubing) running from
the pressure switch to the cold end header box.
3 − Install a manometer with hose from the negative (−)
side of the manometer to the tee installed in the
negative (−) line and with hose from the positive (+)
side of the manometer to the tee in the positive (+)
line.
NOTE − Both sides of the cold end header box are nega-
tive. However the (+) port reads less negative pressure
than the (−) port.
4 − Operate unit and observe manometer reading.
Readings will change as heat exchanger warms.
a. Take one reading immediately after start-up.
b. Take a second reading after unit has reached
steady state (approximately 5 minutes). This will be
the pressure differential.
The pressure differential should be greater
than those listed in table 5.
5 − Remove thermostat demand and allow to cycle off.
6 − Remove manometer and tee’s. Reinstall combustion
air sensing hoses to the pressure switch.
To Cold End Header Box
Field Provided Tubing
To Pressure Switch
To Cold End Header Box
Black Tubing
(po)
Red Tubing
(negative −)
+"
High
−"
Low
C−Blower Compartment
Blower motor (B3) and capacitor (C4), are located in the
blower compartment. The blower compartment can be ac-
cessed by removing the blower access panel.
FIGURE 12
Blower Motor Housing
To Remove Blower From Unit: Disconnect Power, Remove
Control Box, Remove Bolts and Unplug Motor Wires From
Integrated Control. Then Slide Out Front of Unit.
MOTOR
CAPACITOR
BOLTS
1.Blower Motor (B3) and Capacitor (C4)
All EL195DF units use single−phase direct−drive blower mo-
tors. All motors are 120V permanent split capacitor motors
to ensure maximum efficiency. See SPECIFICATIONS table
at the front of this manual for more detail. See motor name-
plate for capacitor ratings.
