E 2007 Lennox Industries Inc.
Dallas, Texas, USA
CONTROLS
KITS AND ACCESSORIES
505,114M
12/07
Supersedes 07/06
Litho U.S.A.
NTC BYPASS CONTROLLER
KIT
INSTALLATION INSTRUCTIONS FOR NTC BYPASS CONTROLLER KIT (11W31; 100809−01)
USED WITH L CONNECTION
®
NETWORK
Shipping and Packing List
Package 1 of 1 contains:
1 − NTC Bypass Controller
1 − Wiring diagram
NOTE − A static pressure transducer is required for proper operation and must be ordered separately.
Check controller for shipping damage. Receiving party should contact last carrier immediately if shipping damage is found.
These instructions are intended as a general guide and do not supersede local codes in any way. Authorities having jurisdiction should be consulted before installation.
Application
The NTC Bypass Controller is used in bypass damper changeover zoning applications. The Bypass Controller is used on units controlled by a Network Thermostat Control
(NTC). The Bypass Controller modulates bypass dampers based on readings from a supply duct static pressure sensor (ordered/shipped separately).
The bypass damper will modulate open as the duct static increases.
A
B
1
2
3
Damper rotates counterclockwise closed
4
5
6
DIP switch B
7
8
DIP SWITCHES
(figure 2)
TERMINAL
BLOCK
JUMPER PINS
(figure 3)
Figure 1. Bypass Controller
DIP switch A
WARNING
Improper installation, adjustment, alteration, service or maintenance can cause property damage, personal injury or loss of life. Installation and service must be performed by a qualified installer or service agency.
1
2
3
4
5
6
7
8
Figure 2. Bypass Controller Dip Switches
CAUTION
Danger of sharp metallic edges. Can cause injury.
Take care when servicing unit to avoid accidental contact with sharp edges.
Bypass Controller Setup
1. Locate the bypass controller DIP switches (figure 1) and set as shown in figure 2.
2. Locate the bypass controller jumpers (figure 1) and install as shown in figure 3.
1
2
INSTALL
JUMPERS
3
4
5
6
7
8
9
10
11
12
Figure 3. Bypass Controller Jumpers
12/07
*2P1207* Page 1
505,114M
*P505114M*
Installation
1. Install the Bypass Controller in the unit or on the side of the supply duct two−thirds of the way down the lon-
gest duct (near the pressure sensor). See figure 4.
SUPPLY DUCT
BYPASS
CONTROLLER
KNOB SECURE
WITH
SCREWS
Figure 4 . NTC Bypass Controller (A153)
2. Install the static pressure sensor (A30) on the side of the supply duct two−thirds of the way down the longest
duct (see figure 5). Secure with two #8 self−tapping
screws.
FeedBk
INPUT
A153
BYPASS
CONTROLLER
RED
RED
24V Pwr
SHIELD Take voltage readings at one of these two locations
BLACK
Common
BLACK
SHIELD
STATIC PRESSURE SENSOR
Figure 5 . Install Static Pressure Sensor (A30)
Wiring
1. Connect wiring as shown in figures 6 and 7.
2. Affix wiring diagram to inside unit panel near other diagrams.
Common
+24VAC
Transformer
0
+
(0−10 VDC
Output)
(24 VAC Input)
Take voltage readings at one of these two locations
− Common (all voltages))
A30 Pressure Sensor
MA SIG
OUTPUT
B9 Bypass
Damper Actuator
24VAC
Common
+4−20mA
Figure 6. Wiring
Page 2
Figure 7. T−Class/3rd Party Unit Low Voltage Wiring for CAV Bypass Zoning
Page 3
Static Pressure Sensor Setup
Remove cover from pressure sensor and remove the
0−10Vdc jumper and set the output range as shown figure
8.
REMOVE
0−10Vdc
JUMPER
JUMPERS − as shipped for
IMC application.
0−10vdc and
0−5" w.c.
JUMPER
SHOULD
JUMPER −
BE @ 0−5"w.c.
modified for
NTC Bypass
Controller.
0−5vdc and
0−5" w.c.
POSITION
JUMPER − modified for
NTC Bypass
Controller.
0−5vdc and
0−2.5" w.c.
JUMPER − modified for
NTC Bypass
Controller.
0−5vdc and
0−1.25" w.c.
SEE FIGURE 10.
Figure 8. Pressure Sensor Jumper Settings
Use the following steps to adjust the range:
1. Apply power to unit.
2. Set Zone Link SW1 MAX DMP DIP switch on to open all zone dampers and bring on the unit blower. See fig-
ure 9.
Opens all zone dampers to maximum open and turns on unit blower.
Figure 9. Zone Link SW1 DIP Switch
3. Connect a voltmeter (use DC volt setting) between the
"0" and "−" terminals of the pressure transducer (see
figure 10).
4. Make sure Bypass Controller knob is set to 100%.
VOLTMETER
DC
Common
+
24v C 0−5v output
Figure 10 . Connect Voltmeter
5. Measure pressure transducer Vdc output. If less than
2.50 Vdc, select next lower static pressure range
(move jumper to 0−2.5 w.c., figure 8).
6. Measure pressure transducer Vdc output with new range selected.
7. If 2.5 Vdc or greater, find percentage in table 1. This
will be the bypass controller setpoint.
50
60
70
80
90
100
%)
0
10
20
30
40
Vdc
Table 1. Pressure Transducer Outputs
Output Voltage
Static Pressure Range Setting
(in. w.c.)
0 − 5 Vdc
0.00
0.50
1.00
1.50
2.00
2.50
3.00
3.50
4.00
4.50
5.00
0 − 5
0.00
0.50
1.00
1.50
2.00
2.50
3.00
3.50
4.00
4.50
5.00
0 − 2.5
0.00
0.25
0.50
0.75
1.00
1.25
1.50
1.75
2.00
2.25
2.50
0 − 1.25
0.00
0.13
0.25
0.38
0.50
0.63
0.75
0.88
1.00
1.13
1.25
Example: If the pressure transducer voltage output is 3.5
Vdc, then the corresponding percentage is 70%; rotate knob to 70%. If fine tuning is required, use the following procedure:
S rotate knob slightly clockwise (higher setting) to maintain a higher operating static pressure control point.
S rotate knob counter−clockwise (lower setting) to maintain a lower operating static pressure control point.
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