Trane VUV Installation, Operation And Maintenance Manual page 30

Installation - Controls
Customer Supplied Terminal Interface
(CSTI)
The control interface is intended to be used with a field-
supplied, low-voltage thermostat or controller. The control box
contains a relay board which includes a line voltage to 24-volt
transformer, quiet contactors (for electric heat units), and an
optional disconnect switch. All end devices are wired to a low-
Figure 27. CSTI adapter board and field connections
The CSTI adapter board provides all the hookups as the
standard adapter board, but in addition, provides hookups for
valve control (main and auxiliary coils), electric heat control,
and damper control. Screw terminal blocks provide convenient
access to fan controls and to end device control. In addition, a
courtesy 10-Vdc supply is provided for use with an external
potentiometer or rheostat. The 10-Vdc supply supports up to
10 mA draw.
TB3 (right 13 positions) is normally used to provide:
• 24 Vac supply to a wall fan speed switch or
• 24 Vac supply to a field-installed unit-mounted controller,
or a wall-mounted controller or thermostat
• Inputs (returns) for thermostatic fan control: High, Medium,
and Low
• Inputs (returns) for cooling/heating requests
• Inputs (returns) for electric heat requests
• Inputs (returns) for damper operation requests
TB4 (left three positions) is normally used to control the system
with a 0–10 Vdc input from a thermostat/controller with a
variable speed output, or a fan control rheostat.
The terminal block functional assignments and polarity are
shown for reference only, and the schematics that ship with
each unit should be consulted before wiring. Wiring
assignments are configured for each unit.
30
voltage terminal block and are run-tested, so the only a power
connection and thermostat connection is needed to
commission the unit.
Entering water temperature sensor is factory mounted on the
supply water pipe. If there are problems sensing accurate
temperature for non-flowing water, move entering water
temperature sensor as far down the supply line as possible to
get accurate water temperatures.
1. VSP 10V
2. VSP 0–10V
3. VSP DC COM
1. 24 Vac B (hot)
2. 24 Vac Y (gnd)
3. High
4. Medium
5. Low
6. V1Op/Cooling
7. V1Cl (not std)
8. Not used
9. Not used
10. V2Op/EH1St/Heating
11. V2Cl/EH2St (not std)
12. Damper Open
13. Dmp Cl (not std)
CSTI Adapter Board Configuration
CAUTION
Burn Hazard!
Failure to follow this instruction could result in the unit
overheating and becoming hot to the touch, which
could result in minor or moderate injury, and/or
equipment damage. If SW4 is turned off, the factory/
customer controller/thermostat will be able to actuate
the electric heat while hot water is available or if the
fans have failed. This switch should NOT be turned off
if the unit schematic indicates that it should be on, to
prevent overheating of the unit (due to simultaneous
electric heat and hydronic heat actuation, or failure of
the fan) and to use the preferred hydronic heating over
electric heat.
For CSTI units, the board mounted switches have to be set
appropriately to enable the desired functionality.
Figure 28. CSTI board-mounted switches
UV-SVX005G-EN