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V-TYPICAL OPERATING CHARACTERISTICS
A-Blower Operation and Adjustment
1 - Blower operation is dependent on thermostat control
system.
2 - Generally, blower operation is set at thermostat sub
base fan switch. With fan switch in ON position, blower
operates continuously. With fan switch in AUTO posi
tion, blower cycles with demand or runs continuously
while heating or cooling circuit cycles.
3 - Depending on the type of indoor thermostat, blower
and entire unit will be off when the system switch is in
OFF position.
B-Temperature Rise (Figure 54)
Temperature rise for EL296UHE units depends on unit in
put, blower speed, blower horsepower and static pressure
as marked on the unit rating plate. The blower speed must
be set for unit operation within the range of “TEMP. RISE
°F” listed on the unit rating plate.
FIGURE 54
TEMPERATURE RISE
Supply Duct Temperature ________
Return Duct Temperature
_
_____
Temperature Rise = ________
SUPPLY
AIR
Temperature
s
RETURN AIR
C-External Static Pressure
1 - Tap locations shown in figure 55.
2 - Punch a 1/4” diameter hole in supply and return air ple
nums. Insert manometer hose flush with inside edge of
hole or insulation. Seal around the hose with perma
gum. Connect the zero end of the manometer to the
discharge (supply) side of the system. On ducted sys
tems, connect the other end of manometer to the return
duct as above.
3 - With only the blower motor running and the evaporator
coil dry, observe the manometer reading. Adjust blow
er motor speed to deliver the air desired according to
the job requirements. For heating speed (second
stage heat speed) external static pressure drop must
not be more than 0.5” W.C. For cooling speed (second
stage cool speed) external static pressure drop must
not be more than 0.5” W.C.
4 - Seal the hole when the check is complete.
FIGURE 55
EXTERNAL STATIC PRESSURE
Supply Duct Static ________
Return Duct Static + _____
Total Duct Static = ________ (dry coil)
Duct Static
or
Supply Air
Return Air
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