Trane VAV SVX02B EN Thermostat User Manual

Home

href="
Installation/  
Operation  
Maintenance  
VariTrane™  
Pneumatic Controls  
March 2002  
VAV-SVX02B-EN  
href="
Thermostat  
Figure 1–Two-Pipe RemoteThermostat (Reverse-Acting)  
Thermostat Selection  
and Location  
In general, both one- and two-pipe  
thermostats have a gain of 2.5 psi per  
degree Fahrenheit, unless special  
thermostats are used that provide a  
different gain. The major difference  
between them is that a one-pipe  
thermostat is considered a low-  
capacity thermostat and a two-pipe  
thermostat is considered a high-  
capacity thermostat.  
Tee  
Two-Pipe  
Remote-Mounted  
T-Stat  
(Reverse-Acting)  
When selecting between one-pipe and  
two-pipe thermostats consider the  
following:  
S
Use one-pipe thermostat when:  
— tubing runs are less than 50 feet from  
thermostat to controller.  
— a single thermostat will control no  
more than three controllers.  
— slower response is desired from the  
thermostat.  
Figure 2–Typical One-PipeThermostat (Reverse-Acting)  
Use two-pipe thermostat when:  
— tubing runs exceed 50 feet from  
thermostat to controller.  
— a single thermostat will control four or  
more controllers.  
— high capacity air is required due to  
restrictions in the air line.  
Restrictor  
One-Pipe  
Remote-Mounted  
T-Stat  
Tee  
Tee  
(Reverse-Acting)  
Thermostat Piping  
Restricted Leg  
The two-pipe thermostat (Figure 1)  
includes a restrictor (internally). Attach  
supply air line and output pressure  
(branch) line to the thermostat.  
The one-pipe thermostat (Figure 2)  
requires an external restrictor tee.  
Connect main air supply to restricted  
leg of restrictor tee. Connect branch line  
from restrictor tee to the thermostat.  
S
20  
(137.9)  
Fan  
P.E.  
Switch1  
(N.O.)  
9 PSI  
(62.06 kPa)  
VAV-SVX02B-EN  
2
href="
Thermostat  
Specifications  
Operation  
Figure 4 illustrates the pressure/  
temperature characteristics for a  
reverse-acting thermostat. As room  
temperature increases, the thermostat  
output pressure decreases.  
TP970 Series PneumaticT-stats  
Maximum Safe Air Pressure:  
25psi (172 kPa)  
Maximum Safe AirTemperature:  
150°F (66°C)  
Pneumatic thermostats modulate  
output air pressure in response to room  
air temperature. Pneumatic thermo-  
stats fall into two categories: direct-  
acting or reverse-acting.This section  
describes how thermostat output  
pressure responds to changes in room  
temperature.  
Figure 4–Reverse-Acting  
Thermostat Response  
Throttling Range:  
2–10°F (1–5°C)  
Figure 3 graphically illustrates the  
relationship between room  
Gain:  
2.5 psi/°F Adjustable  
temperature and output pressure of a  
direct-acting thermostat.The graph in  
Figure 3 shows that as the room  
temperature increases, so does the  
output pressure of the thermostat.  
Figure 3–Direct-Acting  
Thermostat Response  
InputTemperature  
A thermostat in proper working order  
will be able to output a pressure  
ranging from approximately .5 psi to  
supply air pressure depending on  
distance from indicated setpoint.  
InputTemperature  
VAV-SVX02B-EN  
3
href="
Reversing Relay  
Figure 6–Reversing Relay Connections  
Installation and Operation  
The reversing relay is a proportional,  
non-bleeding device for use in pneu-  
matic control systems where a propor-  
tional signal from a controlling device  
must be reversed (see Figure 5).The  
most common use of the reversing  
relay is to change the action of a  
pneumatic thermostat.  
Output  
Branch  
S
20  
(137.9)  
Figure 5–Pneumatic Reversing Relay  
Trane Part No. RLY-755  
9 PSI In  
(62.06 kPa)  
B
M
S
Reversing  
Relay  
9 PSI Out  
(62.06 kPa)  
Input  
Branch  
The reversing relay requires three  
piping connections: main/supply air,  
input signal air, and output branch air  
(see Figure 6).The branch line pressure  
decreases in direct proportion to an  
increase in the input signal pressure  
and vice-versa.The input signal is also  
amplified, thereby minimizing any  
pneumatic line transmission lag  
(see Figure 7).  
Input pressure to the relay and output  
pressure to the PR should always add  
up to a constant, which is usually set  
between 16 and 25 psi. For example,  
with a constant of 18, six-pound input  
signal will result in a 12 pound branch  
signal. A bias adjustment screw is  
provided to retard or advance the out  
signal.  
Figure 7–Reversing Relay Characteristics  
15  
12  
3
15  
3
6
Inc.  
Input Pressure Signal  
VAV-SVX02B-EN  
4
href="
Reversing Relay  
Calibration  
Figure 8–Recalibrating Reversing Relay  
By using the “bias” adjustment on the  
relay, the factory-set 8.0–9.0 “cross-  
over” can be changed.To recalibrate,  
the relay should be connected as  
illustrated in Figure 8.  
Gage  
1
C
3
Pressure  
Regulator  
Bias  
Adjustment  
Screw  
M
M
If the new desired “cross-over”  
pressure is 11.0 psi, this must be applied  
to port #3 by adjusting the pressure  
regulator.The “bias” adjustment is then  
turned until 11.0 psi is obtained on the  
output gage.Turning the “bias” adjust-  
ment “CW” increases the output;  
“CCW” decreases it.  
This 11.0 psi “cross-over” would yield  
the following operational chart:  
New Cross-over pressure  
Chart  
Input:  
Output:  
1
20  
2
19  
3
18  
4
17  
5
16  
6
15  
7
14  
8
13  
9
12  
10  
11  
11  
10  
12  
9
13  
8
14  
7
15  
6
16  
5
17  
4
18  
3
19  
2
20  
1
Specifications  
Ambient Limits:  
+40°F/+120°F operating (+4°C/+49°C)  
Maximum Pressure:  
30 psig  
Connections:  
3/16" (4.& mm) nipples for ¼" (6.4 mm) OD  
polyethylene tubing  
Mounting:  
In-line via air connections  
Factory Settings:  
9 psig in./9 psig out and 8 psig in./8 psig  
out  
Air Consumption:  
0.5 SCFH (.236 L/M) @ 20 psig  
Material:  
ABS  
Bias Adjustment:  
+/-15 psi  
Weight:  
3 ½ oz  
VAV-SVX02B-EN  
5
href="
Model 3011—Pneumatic  
Volume Regulator  
Installation  
Model 3011  
1. Attach bracket either vertically or horizontally to the illustration surface. Horizontal  
is preferred, vertical is acceptable, any other position is not acceptable (see Figure 9).  
The model 3011 PneumaticVolume  
Regulator (PVR) is capable of operating  
with normally-open or normally-closed  
air valves and can operate with either  
direct-acting (DA) or reverse-acting  
(RA) thermostats.  
2. Insert controller into its bracket. Controller may be face up, face down, face left, or  
face right.The controller LO and HI stat delta P must be calibrated in the same  
position that it is mounted.  
Figure 9–Acceptable Installation Positions  
Connections  
Figure 10 illustrates a typical piping diagram of a normally-open or normally-  
closed unit.  
Figure 10–Typical Piping Diagram of Normally-Open or Normally-Closed Unit  
Normally-Open Unit or  
Normally-Closed Unit  
One-Pipe  
Remote-Installed  
T-Stat  
Volume  
Regulator  
LO  
Restrictor  
Tee  
HI  
T
H
LO STAT P  
B
Actuator  
HI STATP  
R
N
N
Restricted Leg  
M
RESET SPAN  
DAMPER  
G
Airflow Sensor  
S
S
20  
20  
Selecting Direct- or Reverse-Acting Thermostat (3011)  
The model 3011 PVR must be calibrated to operate with either a direct-acting or  
reverse-acting thermostat.The control must also be changed when used with a  
normally-open or normally-closed air valve.  
VAV-SVX02B-EN  
6
href="
Model 3011—Pneumatic  
Volume Regulator  
Use the following procedure to set-up the PVR:  
1. Select damper action (NO or NC). Loosen damper selection switch screw and align to either the NO or NC pointer with damper  
pointer and tighten screw.  
2. Now determine the type of thermostat that will be used. If a direct-acting thermostat is used, the reset start pressure is typically  
8 psi. If a reverse-acting thermostat is used, the reset start pressure is typically 3 psi (see Figure 11).  
3. With an accurate gage (0-10 psi) connected to port “G, regulate the thermostat pressure to port “T” to desired start point pressure.  
4. Adjust reset start to indicate 0 psi on port “G” and continuing adjusting to indicate a pressure slightly higher than 0 psi, (i.e., 0.1 psi).  
Figure 11–Adjusting Reset Start  
Adjust to obtain 0–0.1 psi at port G  
Connect Hand Pump  
Input desired LO stat  
pressure at t-stat port  
0–20 psi  
RESET START  
Handpump  
B
LO STAT P  
HI STAT P  
NO  
M
DAMPER  
psi  
RESET SPAN  
10  
Connect 0–10 psi Gage  
0
G
Factory-set at 5 psi  
Adjustable (0–10 psi)  
NOTE: The arrows on the damper selector must be aligned  
exactly or the range of the controller will be limited .0 psi  
Adjusting the Reset Span (3011)  
The reset span is factory-set at 5 psi.This is the thermostat pressure difference from which the PVR delivers flow from minimum  
to maximum setpoints.This range is not normally changed unless a special control scheme is used where control operation  
must be changed.  
To field adjust a different reset span, follow these steps:  
1. Connect an accurate gage to port “G.  
2. Apply 20 psi to port “T.  
3. Adjust reset span to indicate the desired span on port “G” (see Figure 12).  
4. LO-stat and HI-stat delta P must now be readjusted (see following calibration procedure)  
Figure 12Adjusting Reset Span  
Apply 20 psi  
T
H
RESET START  
LO STAT  
P
B
HI STAT  
P
NO  
R
M
RESET SPAN  
DAMPER  
G
PSI  
Adjust to obtain desired reset span  
0
VAV-SVX02B-EN  
7
href="
Calibration  
Procedures  
Calibration Procedure (Steps 1–4 apply to all thermostat models)  
1. Be sure the PVR is installed correctly and that all connections are hooked up to the proper ports. See Figure 9 for unit application.  
2. Remove the caps on the tees which are connected to the lines to the flow sensor. Connect a 0–2" magnehelic gage to monitor  
flow sensor delta P. The higher-pressure port is further upstream on the air valve inlet.  
3. Remove the thermostat line and connect a hand pump with a 0–20 psi gage to port “T.  
4. Tee a 0–20 psi gage in the line from port “B” on the volume regulator to the air valve actuator.  
Normally-OpenValve  
Normally-OpenValve  
Reverse-Acting Thermostat  
(See Figure 13 for proper  
connections):  
Reverse-Acting Thermostat  
(See Figure 14 for proper  
connections):  
Direct-Acting Thermostat  
(See Figure 13 for proper  
connections)  
Direct-Acting Thermostat  
(See Figure 14 for proper  
connections):  
5. Set port “T” at 0 psi.  
5. Set port “T” at 0 psi.  
5. Set port “T” at 0 psi.  
5. Set port “T” at 0 psi.  
6. Monitor the delta P and  
adjust the LO-stat delta P  
(maximum) adjustment to  
desired maximum. If the  
actuator pressure is less  
than 3 psi, the air valve is  
wide open and duct  
6. Monitor the delta P and  
adjust the LO-stat delta P  
(maximum) adjustment to  
desired maximum flow. If  
the actuator pressure is  
greater than 13 psi, the air  
valve is wide open and  
duct pressure must  
6. Monitor the delta P and  
adjust the LO-stat mini-  
mum) adjustment to  
desired minimum.  
6. Monitor the delta P and  
adjust the LO-stat (mini-  
mum) adjustment to  
desired minimum.  
7. Set port “T” input at 16  
psi or greater with the  
hand pump.  
7. Set port “T” input at  
16 psi or greater with the  
hand pump.  
pressure must increase to  
increase flow.  
8. Monitor the delta P and  
adjust the HI-stat (maxi-  
mum) adjustment to  
8. Monitor the delta P and  
adjust the HI-stat  
increase to increase flow.  
7. Set prot “T” to 16 psi  
7. Set prot “T” to 16 psi  
or greater with the  
hand pump.  
(maximum) adjustment  
to desired maximum flow.  
If the actuator pressure is  
greater than 13 psi, the air  
valve is wide open and duct  
pressure must increase to  
increase flow.  
or greater with the  
hand pump.  
desired maximum flow. If  
the actuator pressure is  
less than 3 psi, the air  
valve is wide open and  
duct pressure must  
8. Monitor the delta P and  
adjust the HI-stat (mini-  
mum) adjustment to  
8. Monitor the delta P and  
adjust the HI-stat (mini-  
mum) adjustment to  
desired minimum flow.  
increase to increase flow.  
desired minimum flow.  
9. Set port “T” at 0 psi.  
9. Set port “T” at 0 psi.  
9. Set port “T” at 0 psi.  
9. Set port “T” at 0 psi.  
10.Monitor the maximum  
flow delta P. If it is not  
correct, adjust the LO-stat  
adjustment knob.  
10. Monitor the minimum  
flow delta P. If it is not  
correct, adjust the LO-stat  
adjustment knob.  
10.Monitor the minimum  
flow delta P. If it is not  
correct, adjust the LO-stat  
adjustment knob.  
10.Monitor the maximum  
flow delta P. If it is not  
correct, adjust the LO-stat  
adjustment knob.  
Figure 13Connections of Direct/Reverse-Acting  
Thermostat with Normally-Open Valve  
Figure 14Connections of Direct/Reverse-Acting  
Thermostat with Normally-Closed Valve  
02' Magnahelic Gage  
HI LO  
02' Magnahelic Gage  
HI LO  
Normally-Closed Unit  
Normally-Open Unit  
Apply 20 psi  
Volume  
Regulator  
Apply 20 psi  
Volume  
Regulator  
LO  
LO  
HI  
HI  
T
T
H
H
RESET START  
LO STAT  
RESET START  
LO STAT  
P
P
B
B
Actuator  
Actuator  
HI STAT  
P
HI STAT  
P
PSI  
R
R
N
NO  
NC  
M
M
DAMPER  
DAMPER  
0
10  
0
10  
Connect 020 psi Gage  
Connect 020 psi Gage  
G
G
Airflow Sensor  
Airflow Sensor  
Connect Hand Pump  
02 psi  
Handpump  
Connect Hand Pump  
02 psi  
Handpump  
S
20  
S
20  
8
VAV-SVX02B-EN  
href="
Specifications (3011)  
Specifications (3011)  
Differential Pressure Range:  
0 to 1.0 in. wg  
Minimum Setpoint Range:  
0 to 1.0" H2O  
Normal Supply Air Pressure:  
20.0 psi  
Reset Span Range:  
010 psi  
Minimum Supply air Pressure:  
15.0 psi  
Maximum SafeThermostat Input:  
30 psi (closed chamber)  
Maximum Supply Air Pressure:  
30.0 psi  
OperatingTemperature:  
+40/+120°F  
Maximum Setpoint Range:  
minimum to 1.0 in. wg  
Average Supply Air Consumption:  
28.8 scim at 20 psi  
StorageTemperature:  
-40/+140°F  
Operating Static Range:  
0.256.0 in. wg  
Thermostat Pressure Input Range:  
Adjustable 010 psi band from 0–20 psi  
Main,Thermostat, Actuator and Static  
Pick-up Connections:  
.250 O.D.  
Reset Start Point Range:  
0–10 psi  
VAV-SVX02B-EN  
9
href="
Model 3501—Pneumatic  
Volume Regulator  
Installation  
Adjusting the Reset Span (3501)  
Model 3501  
1. Attach bracket either vertically or  
horizontally to the installation surface.  
Horizontal is preferred, vertical is  
acceptable, any other position is  
not acceptable.  
The reset span is factory-set at 5 psi.  
This is the thermostat pressure differ-  
ence from which the PVR delivers  
flow from minimum to maximum  
setpoints.This range is not normally  
changed unless a special control  
scheme is used where control  
The model 3501 PneumaticVolume  
Regulator (PVR) is capable of operating  
with normally-open or normally-closed  
air valves and can operate with either  
direct-acting (DA) or reverse-acting  
(RA) thermostats.  
2. Insert controller into its bracket.  
Controller may be face up, face down,  
face left, or face right.The controller  
LO and HI stat delta P must be  
calibrated in the same position that it  
is installed.  
operation must be changed.  
To field adjust a different reset span,  
follow these steps:  
1. Connect an accurate gage to port “G.  
Selecting Direct- or Reverse-Acting  
Thermostat (3501)  
2. Apply 20 psi to port “T.  
3. Adjust reset span to indicate the  
desired span on port “G.  
The model 3501 PVR must be calibrated  
to operate with either a direct-acting or  
reverse-acting thermostat.The control  
must also be changed when used with  
a normally-open or normally-closed  
air valve.  
4. LO-stat and HI-stat delta P must now  
be readjusted (see following  
calibration procedure).  
Use the following procedure to set-up  
the PVR:  
1. Select damper action (NO or NC).  
Loosen damper selection switch  
screw and align to either the NO or  
NC pointer with damper pointer and  
tighten screw.  
2. Now determine the type of thermostat  
that will be used. If a direct-acting  
thermostat is used, the reset start  
pressure is typically 8 psi. If a reverse-  
acting thermostat is used, the reset  
start pressure is typically 3 psi.  
3. With an accurate gage (0–30 psi)  
connected to port “G, regulate the  
thermostat pressure to port “T” to  
10.5 psi.  
4. Adjust reset start to indicate 2.5 psi on  
port “G”  
10  
VAV-SVX02B-EN  
href="
Calibration  
Procedures  
Calibration Procedure (Steps 14 apply to all thermostat models)  
1. Be sure the PVR is installed correctly and that all connections are hooked up to the proper ports.  
2. Remove the caps on the tees, which are connected to the lines to the flow sensor. Connect a 0–2" magnehelic gage to monitor  
flow sensor delta P.The higher-pressure port is further upstream on the air valve inlet.  
3. Remove the thermostat line and connect a hand pump with a 0–20 psi gage to port “T.  
4. Tee a 0–20 psi gage in the line from port “B” on the volume regulator to the air valve actuator.  
Normally-Open Valve  
Normally-Closed  
Direct-Acting Thermostat  
5. Set port “T” at 0 psi.  
Reverse-Acting Thermostat  
5. Set port “T” at 0 psi.  
Direct-Acting Thermostat  
5. Set port “T” at 0 psi.  
Reverse-Acting Thermostat  
5. Set port “T” at 0 psi.  
6. Monitor the delta P and  
adjust the LO-stat delta P  
(maximum) adjustment to  
desired maximum. If the  
actuator pressure is less  
than 3 psi, the air valve is  
wide open and duct  
6. Monitor the delta P and  
adjust the LO-stat  
6. Monitor the delta P and  
adjust the LO-stat delta P  
(maximum) adjustment to  
desired maximum. If the  
actuator pressure is  
6. Monitor the delta P and  
adjust the LO-stat  
(minimum) adjustment to  
desired minimum.  
(minimum) adjustment  
to desired minimum.  
7. Set port “T” input at  
16 psi or greater with  
the hand pump.  
7. Set port “T” input at  
16 psi or greater with  
the hand pump.  
greater than 13 psi, the air  
valve is wide open and  
duct pressure must  
pressure must increase  
to increase flow.  
8. Monitor the delta P and  
adjust the HI-stat  
8. Monitor the delta P and  
adjust the HI-stat  
increase to increase flow.  
7. Set prot “T” to 16 psi  
or greater with the  
hand pump.  
7. Set prot “T” to 16 psi  
or greater with the  
hand pump.  
(maximum) adjustment to  
desired maximum flow. If  
the actuator pressure is  
greater than 13 psi, the air  
valve is wide open and duct  
pressure must increase to  
increase flow.  
(maximum) adjustment to  
desired maximum flow. If  
the actuator pressure is  
less than 3 psi, the air  
valve is wide open and  
duct pressure must  
8. Monitor the delta P and  
adjust the HI-stat  
8. Monitor the delta P and  
adjust the HI-stat  
(minimum) adjustment  
to desired minimum flow.  
(minimum) adjustment to  
desired minimum flow.  
increase to increase flow.  
9. Set port “T” at 0 psi.  
9. Set port “T” at 0 psi.  
9. Set port “T” at 0 psi.  
9. Set port “T” at 0 psi.  
10. Monitor the minimum  
flow delta P. If it is not  
correct, adjust the LO-stat  
adjustment knob.  
10. Monitor the maximum  
flow delta P. If it is not  
correct, adjust the LO-stat  
adjustment knob.  
10. Monitor the minimum  
flow delta P. If it is not  
correct, adjust the LO-stat  
adjustment knob.  
10.Monitor the maximum  
flow delta P. If it is not  
correct, adjust the LO-stat  
adjustment knob.  
VAV-SVX02B-EN  
11  
href="
Specifications (3501)  
Specifications (3501)  
Differential Pressure Range:  
0 to 1.0 in. wg  
Minimum Setpoint Range:  
0 to 1.0" H2O  
Output Sensitivity:  
5 psi/.02  
Average Supply Air Consumption:  
43.2 scim at 20 psi  
Reset Start Point Range:  
0–10 psi  
Maximum Setpoint Range:  
minimum to 1.0 in. wg  
Reset Span Range:  
0–7 psi  
Maximum Setpoint Range:  
6.0 in. wg  
OperatingTemperature:  
+40/+120°F  
Normal Supply Air Pressure:  
20.0 psi  
StorageTemperature:  
-40/+140°F  
Minimum Supply air Pressure:  
15.0 psi  
Maximum Supply Air Pressure:  
30.0 psi  
12  
VAV-SVX02B-EN  
href="
MCP-3631—Rotary  
Pneumatic Damper Actuator  
Installation Method:  
Specifications:  
Effective Area:  
8 sq in. (52 sq cm)  
Normal Rotation:  
100 deg  
MCP-3631—Rotary  
Pneumatic Damper Actuator  
Description:  
Rotary actuators mounts to a standard  
½" diameter shaft by a locking collar  
and bushing.  
Slide collar onto shaft. Slide actuator  
onto shaft noting directional rotation.  
Slide bushing onto shaft into actuator,  
aligns actuator with damper, lock  
collar and bushing set screws, and  
install bracket.  
Supply Pressure:  
0 to 20 psig (138 kPa) operating  
30 psig (207 kPa) max  
Spring Ranges:  
Retracted/extendedTorque  
(Based on 0 & 20 psi applied)  
Models:  
Maintenance:  
No routine maintenance is required.  
MCP-3631-5000 8–13 psi range  
(55–90 kPa) Normally-Closed operation  
MCP-3631-8000 3–8 psi range  
(21–55 kPa) Normally-Open operation  
8–13 psi (55–90 kPa);  
68/59 in. lbs (8/7 Nm) @ 90 deg  
3–8 psi (21–55 kPa);  
25/102 in. lbs (3/12 Nm) @ 90 deg  
Supply Connection:  
3/16" (5 mm) nipple for ¼" (6 mm)  
OD polyethylene tubing  
Material:  
Body  
Glass-filled nylon  
Diaphragm Neoprene  
Weight:  
1.5 lbs (0.68 kg)  
Ambient Limits:  
Operating -20°F120°F (-29°C49°C)  
Shipping  
-40°F140°F (-40°C–60°C)  
VAV-SVX02B-EN  
13  
href="
Constant-Volume Dual-Duct  
Calibration (3011)  
This PVR does not require a thermostat  
connected to the PVR.  
3. Set t-stat to full cool.  
ConstantVolume Dual-Duct  
Calibration (3011)  
4. Set HI thermostat (minimum) to  
the desired minimum flow on the  
heating deck.  
The following procedure must be used  
when calibrating a constant-volume  
dual-duct unit. See Figure 15 for a  
typical piping diagram.  
This calibration procedure is used when  
a constant volume of air must be  
maintained through a unit. On a dual-  
duct unit, a constant-volume discharge  
sensor is used to measure the air  
leaving the unit.The PVR controlling to a  
constant-volume of air leaving the unit  
uses the discharge sensor to maintain  
the specified cfm.  
5. Set LO thermostat adjustment knob  
on cooling deck (CV deck) to desired  
constant-volume.  
6. Exercise the system to check flows  
for proper operation.  
1. Set t-stat to full heat.  
2. Set LO thermostat (maximum) to the  
desired maximum flow on the  
heating deck.  
Figure 15Typical Constant-Volume  
Dual-Duct Piping Diagram  
Constant-Volume  
Flow Ring  
LO  
HI  
Outlet  
T
H
L
Cooling  
Valve  
Heating  
Valve  
B
Actuator  
Volume  
Regulator  
Normally-  
Open  
Normally-  
Open  
M
LO  
HI  
S
G
20  
(137.9)  
Two-Pipe  
Remote-Mounted  
T-Stat  
(Direct-Acting)  
T
H
L
Restrictor  
Tee  
B
Actuator  
Volume  
Regulator  
S
M
20  
(137.9)  
G
S
20  
(137.9)  
14  
VAV-SVX02B-EN  
href="
Variable Air Volume Dual-Duct  
Calibration (3011)  
Figure 16–Typical VAV Dual-Duct Piping Diagram  
Variable-Air-Volume Dual-  
Duct Calibration (3011)  
Figure 16 is a typical piping diagram of  
aVAV dual-duct unit.The unit has a  
thermostat piped to both pneumatic  
volume regulators (PVR) which will  
operate the heating deck from a  
thermostat signal of 3–8 psi.The cooling  
deck will operate from a thermostat  
signal of 8–13 psi.With normal  
calibration of the PVR, the unit will have  
both the heating and cooling deck at  
minimum with a thermostat signal of  
8 psi.  
Outlet  
T
H
L
Heating  
Valve  
Cooling  
Valve  
B
Actuator  
Volume  
Regulator  
Normally-  
Open  
Normally-  
Open  
LO  
HI  
LO  
HI  
S
20  
(137.9)  
G
Two-Pipe  
Remote-Mounted  
T-Stat  
(Direct-Acting)  
T
H
L
Restrictor  
Tee  
In order to have a unit minimum cfm  
and still have 0 cfm minimums on both  
the heating and cooling deck, special  
calibration is required.The PVR has a  
“reset start” adjustment knob, which  
allows the unit to be calibrated to a  
minimum cfm.This is achieved by  
crossing over the thermostat ranges.  
Figure 17 illustrates this concept.  
B
Actuator  
Volume  
Regulator  
S
20  
(137.9)  
G
20  
(137.9)  
Figure 17–Example  
Thermostat Range: 3–8 psi  
HeatingValve = 5 psi range  
Thermostat Range: 813 psi  
CoolingValve = 5 psi range  
Unit Minimum 400 cfm  
Approximately 1000 cfm divided by 5 psi =  
200 cfm/1b*  
N.O. HeatingValve  
Min 0 cfm  
Max 1000 cfm  
N.O. CoolingValve  
Min 0 cfm  
Max 1000 cfm  
*Due to the relationship between velocity  
pressure and cfm; for both the cooling and  
heating PVR, a linear relationship between  
cfm and psi does not exist.  
To obtain a unit minimum cfm of 400 cfm, the  
heating deck volume regulator must have its  
thermostat range changed from 3–8 psi to  
4–9 psi.This is adjusted by changing the “reset  
start” point from 3 psi to approximately 4 psi.  
Max  
Unit Min  
Valve Min  
4
The cooling deck volume regulator must have its  
thermostat range changed from 8–13 psi to  
7–12 psi. This is adjusted by changing the “reset  
start” point from 8 psi to approximately 7 psi.  
7
8
9
12  
By overlapping the thermostat spring ranges, we  
were able to have 0 cfm minimum settings on  
both the heat and cool deck and still maintain the  
required unit minimum cfm of 400 cfm.  
The calibration of the PVR is the same as the  
normal calibration procedures previously  
described in this manual.  
VAV-SVX02B-EN  
15  
href="
Constant-Volume  
Single-Duct VAV (VCV 3011)  
1. Be sure there is 0 psi at the “T” port.  
2. Set LO thermostat adjustment knob to  
desired unit cfm.  
Constant-Volume Single-  
Duct VAV (VCV 3011)  
This is used when a constant volume of  
air is required to supply a zone. A  
thermostat is still often required to  
modulate a reheat coil to maintain  
temperature control.The thermostat is  
never connected to the “T” port on the  
volume regulator.The following  
procedure is used to calibrate this type  
of unit with a PVR.  
The unit will now modulate to the  
calibrated cfm setting. See Figure 18 for  
typical constant volume single-duct  
piping diagram.  
Figure 18Typical Constant-Volume Single-Duct Piping Diagram  
HI  
H
L
LO  
T
Flow Ring  
Actuator  
B
Volume  
Regulator  
M
S
S
20  
(137.9)  
20  
(137.9)  
Tee  
Two-Pipe  
Remote-Mounted  
T-Stat  
11  
(75.8)  
(Reverse-Acting)  
Airflow  
Safety Switch  
Stage 1  
12.5  
(86.2)  
Stage 2  
14  
(96.5)  
Stage 3  
P.E. Stage Switch(es)  
(Normally-Open)  
Electric Heater Terminal Box  
Literature Order Number  
File Number  
VAV-SVX02B-EN  
SV-TD-VAV000-SVX02B-EN-0302  
VAV-SVX02A-EN &VAV-IOM-6  
La Crosse  
Supersedes  
Trane  
Stocking Location  
An American Standard Company  
Trane has a policy of continuous product and product data improvement and reserves the right to change design  
and specifications without notice. Only qualified technicians should perform installation and servicing of  
equipment referred to in this publication.  
For more information contact  
your local district office or  
e-mail us at comfort@trane.com  

Honeywell Pro 8000 Thermostat User Manual

Carrier TP NAC Thermostat User Manual

Carrier 33CS2PPRH 01 Thermostat User Manual

Honeywell T87K Thermostat User Manual

White Rodgers 1E56 444 Thermostat User Manual

Lux Products PSD010BC Thermostat User Manual

Bryant TSTATBBPCM01 A Thermostat User Manual

Honeywell T8095A Thermostat User Manual

Bryant TSTATBBPRF01 B Thermostat User Manual

Honeywell 68 0287 04 Thermostat User Manual