Trane VariTrane Installation/ Owner Programming

Installation/
Owner
Programming

VariTrane™ Analog
Electronic Controls

For use with:

Single-Duct Cooling & Reheat Units
Parallel & Series Fan-Powered Units
Low-Height Parallel & Series Fan-Powered Units

November 2001

VAV- SV X 0 3 A- EN

© 2001 American Standard, Inc. All rights reserved

VAV-SVX03A-EN

Contents

General Information

Literature Contents ............................................................................................... 4

Receiving and Handling ......................................................................................... 4

Unit Information

Single-Duct Units ............................................................................................... 4-5

Fan-powered Units ............................................................................................ 4-5

Analog Controls

General
Electonic Controls Installation
Minimum and Maximum Potentiometers Adjustments
Zone Sensor Wiring
Location and Mounting

Sequence of Operation

Single-Duct Units .................................................................................................. 9

Series Fan-powered ............................................................................................. 9

Parallel Fan-powered ............................................................................................ 9

Control Options

Constant-Volume ................................................................................................ 10

Auto Dual Minimum ............................................................................................ 10

Calibration

Transducer Operation ..........................................................................................11

Null Voltage .......................................................................................................... 11

Procedure for Maximum and Minimum Calibration ..............................................11

Set Maximum Flow ..............................................................................................11

Set Minimum Flow .............................................................................................. 12

No Dual Minimum .......................................................................................... 12

Auto Dual Minimum ....................................................................................... 12

Balancing

Balancing Procedure ........................................................................................... 13

Adjustments (Set Maximum and Minimum Flows) .............................................. 13

Installation and Wiring
Zone Sensor

Zone Sensor Operation ....................................................................................... 15

Troubleshooting

Tools and Equipment ........................................................................................... 16

System Check ..................................................................................................... 16

Air Damper and Motor Check .............................................................................. 17

Control Check ...................................................................................................... 17

Zone Sensor Check ............................................................................................. 17

Heater Contactor Check ...................................................................................... 17

Fan Motor Check ................................................................................................. 17

Circuit Board Check ............................................................................................. 17

Transducer Check ................................................................................................ 18

Triac Output Check .............................................................................................. 18

Auto Dual Minimum Check .................................................................................. 18

Electronic Zone Sensor Check ............................................................................. 19

VAV-SVX03A-EN 3

General
Information

Literature Contents

This manual describes the operation,
calibration and set-up of VariTrane VAV
Single-Duct and Fan-powered units
with Analog Electronic Controls.

Receiving and Handling

VariTrane units are shipped completely
assembled with the exception of filters
and accessories. Upon receiving,
please inspect each unit and the
components for shipping damage.

After receiving the units, complete
the following:

 Locate the nameplate and model

number and check that the correct units
have been received.

 Inspect the control units and air damper

casing for dents or punctures.

 Verify that all options have been

included, such as filters, controls,
heating coils, water valves, etc. Also
check that unit voltages agree with the
building parameters.

 Manually rotate the fan (if applicable) to

assure that there are no obstructions
within the housing.

 Claims for in-transit damage must be

filed immediately with the delivery
carrier.

 For re-heat units, check the coil fins and

make sure the coils are not damaged.

 Locate and verify that the correct zone

sensors are with the order. These will
be marked with an orange “Accessories
Enclosed” label. Store in a secure place
until needed. Accessories lost at a
jobsite are NOT covered by Trane’s
warranty.

 If a discrepancy occurs between what

was ordered and what is received,
contact your local Trane representative
immediately.

 Read the appropriate section in this

manual for installation procedures prior
to actual starting of installation.

Warnings and Cautions appear at appropriate sections throughout this manual.
Read these carefully.

WARNINGWARNING

avoided, could result in death or serious injury.

CAUTIONCAUTION

avoided, may result in minor or moderate injury.

CAUTION:CAUTION:

in equipment or property only damage.

4 VAV-SVX03A-EN

— May also be used to alert reader to a situation that could result

NOTICE:

— Indicates a potentially hazardous situation which, if not

— Indicates a potentially hazardous situation which, if not

Unit
Information

Unit Type Description

Analog Electronic VariTrane units use an
electronically-controlled air damper for
primary air modulation. The unit types
available are single-duct units (VCCF,
VCWF, VCEF), series fan-powered units
(VSCF, VSWF, VSEF), parallel fan­powered units, (VPCF, VPWF, VPEF) and
low-height fan-powered units (LSCF,
LSWF, LSEF, LPCF, LPWF, LPEF).

Single-Duct Units

The basic unit consists of an air damper
mounted in a sheet metal casing, which
is used to control the volume of air
introduced to the occupied zone. The
unit is designed to modulate either
cooling or heating air. The basic cooling­only unit can be equipped with reheat
coils located at the discharge of the unit.
Standard choices include an electric coil
with up to three stages of heat or a hot­water coil.

Figure 1 – Typical Single-Duct Units

VCCF

Fan-Powered Units

VariTrane fan-powered units can be
either parallel or series, with or without
re-heat. See Figure 2.

Note: Low-Height is similar to the series
and parallel fan-powered units. All
series and parallel references from this
point on will also include Low-Height
unless noted.

The fan on a series unit runs continu­ously whenever the main air-handler
unit is in operation. There are various
options for starting the fan. The fan can
be started three ways: 1) remotely,

2) by a duct-pressure switch, or 3) by a
combination of both. The particular fan
control method will vary from unit to
unit, depending upon job needs.

Typically, the re-heat is off while the air
damper modulates primary air and
responds to zone temperature. If zone
temperature decreases to the point
where a decrease in primary air will not
maintain the desired temperature, the
re-heat will be activated to increase the
temperature of the discharge air.

On a parallel unit, the VariTrane air
damper delivers primary cooling air to
the unit outlet. When the space
temperature decreases beyond air
damper control, the fan is turned on as
the first stage of heat. The fan delivers

plenum air from above the occupied
space to the unit outlet, which is mixed
with primary air and delivered to the
occupied space.

Note: Either the fan, the air damper or
both can deliver airflow into the
occupied space. In order to prevent
primary airflow from exiting through
the fan when the fan is not running on a
parallel unit, a back-draft damper is
provided. When the fan is not running,
the efficiency of this system is the
same as a standard single duct VAV
unit.

Typically, the control systems applied
to parallel units cause the air damper
to close to zero or a minimum flow
before the fan is activated. After the
fan is activated, the heat will be
activated upon further reduction in
zone temperature. Therefore, little
primary air is mixed with the
heated air.

Fan-powered units are available with
rectangular discharge connection only.
Either straight flange or slip and drive
is available with electric heat. The
electric heater is mounted on the
discharge of the unit. Hot water coils
are connected to the plenum inlet on
parallel units, and to the discharge of
series units.

VCWF

VCEF

VAV-SVX03A-EN 5

Table 1 – Maximum Fan Motor Amperage (FLA)

Fan HP 115 277 347 208

Size VAC VAC VAC VAC

Series/Parallel 01 1/8 1.6 0.7 0.7 —
Series/Parallel 02 1/8 1.6 0.7 0.7 —
Series/Parallel 03 1/3 5.4 1.8 1.5 —
Series/Parallel 04 1/3 5.4 1.8 1.5 —
Series/Parallel 05 1/2 7.6 2.6 2.1 —
Series/Parallel 06 1/2 — 3.8 3.8 6.3
Series/Parallel 07 1 — 4.7 3.6 6.9

Low Height 08 1/8 4.7 1.76 1.52 —
Low Height 09 2 x 1/8 2 x 2.1 2 x 0.79 2 x 0.62 —
Low Height 10 2 x 1/8 2 x 4.7 2 x 1.76 2 x 1.52 —

Figure 2 – Typical Fan-Powered Units

VSCF VSWF

Unit
Information

VSEF

VPCF VPWF

VPEF

6 VAV-SVX03A-EN