Vfd Supply Air Blower Start-Up - Lennox LCH036 Installation Instructions Manual

FIELD WIRING HOT GAS REHEAT UNITS
(Using A Humidity Sensor With More
Than 150 Ft. Wire Runs)
NOT
CONNECTED
ISOLATED 24V
TRANSFORMER
DRAIN
A91
VIN
NOT
CONNECTED
GND
VO
FIGURE 21

VFD Supply Air Blower Start-Up

This section is used when the unit is equipped with an
optional variable frequency drive (VFD) supply air blower.
Install static pressure transducer before start-up; see
Optional Supply Air VFD section in this manual.
A-Set Static Pressure Setpoints
Refer to the Unit Controller manual provided with the unit.
1- Open all zone dampers and/or boxes.
2- Locate the Unit Controller in the control box. Refer to
the dimension illustration in the front of this manual.
Refer to the Unit Controller Installation and Setup Guide to
change the System Mode. Use the menu navigation arrows
and select button; see Settings - Install.
3- Apply power and use the Unit Controller to start the
blower. Press the menu navigation arrows and select
button to initiate the blower. Refer to the Service - Test
menu in the Unit Controller manual. Allow blower
speed to stabilize.
4- Locate TB18 under Unit Controller. Read the DC
voltage at terminals 6 (+) and 10 (-). Divide reading by
2 to determine system static pressure.
TB18-6 & 10
__ .
.
Voltage
5- Static pressure setpoints are factory-set at 1"w.c.
Change the setpoints to match the static calculated in
the previous step or to design specifications. Refer to
the Setting - Control - ECTO menu in the Unit Controller
A55 UNIT
CONTROLLER
P298
J298A
R
1
2 C
B
AI-1
3
4
C
5 HUM
6
7 TMP
D
8
DO-1
9
C
10
DO-2
DI-1
2 = System Static "w.c.
manual. In addition, reference tables 2 and 3. Record
new setpoints in table 4.
6- The Unit Controller is factory-set to shut the unit off if
duct pressure exceeds 2.0"w.c. longer than 20
seconds. This pressure can be changed using ECTO
parameter 0.21. Refer to the Unit Controller manual.
VFD SUPPLY AIR STATIC PRESSURE SETPOINTS
ECTO
Unit de-energized during smoke detection. See ECTO
0.02
5.01 to operate blower during smoke detection.
0.03 During ventilation
0.04 During heating
0.05 During cooling
VFD SUPPLY AIR STATIC PRESSURE SETPOINTS
Pressure "w.c.
0.00
0.25
0.50
0.75
1.00
1.25
1.50
1.75
2.00
2.25
2.50
2.75
3.00
3.25
3.50
3.75
4.00
4.25
4.50
4.75
5.00
RECORD ADJUSTED SETPOINTS
ECTO
Description
0.02 Smoke
0.03 Ventilation
0.04 Heating
0.05 Cooling
B-Unit Operation
Use the Unit Controller to check unit mechanical operation.
See the Service - Test section of the Unit Controller manual.
Page 16
TABLE 2
Changes Static Pressure Setpoint
TABLE 3
DC Voltage
0.00
0.50
1.00
1.50
2.00
2.50
3.00
3.50
4.00
4.50
5.00
5.50
6.00
6.50
7.00
7.50
8.00
8.50
9.00
9.50
10.00
TABLE 4
Setpoint Setpoint
"w.c.
LGH/LCH420, 480, 540, 600
Display Setting
0
13
25
38
51
64
77
89
102
115
128
140
153
166
179
191
204
217
230
242
255
Display
Setting