2
Operation overview
The VC3xxxX Series Line Voltage Switching Transformer Relay Pack(s) operate as slave unit(s) under the control of a single
master VTR73xxA Terminal Equipment Controller.
Fan operation can be configured and wired for the following:
o
3 Speed configuration using 3 fan relays ( Low – Med - High )
o
2 Speed configuration using 2 fan relays ( Low - High )
o
3 Speed configuration with Auto fan speed mode using 3 fan relays ( Low – Med - High )
o
2 Speed configuration with Auto fan speed mode using 2 fan relays ( Low - High )
o
Single fan speed configuration.
The VTR7300 Controller can be configured for typical 2 or 4 pipe heating / cooling FCU applications.
2 or 4 pipe only operation can be configured and wired for the following:
o
Cooling
only
o
Heating
only
o
Cooling / Heating with network or local auto changeover
2 or 4 pipe only with electric reheat can be configured and wired for the following:
o
Cooling
only
o
Heating
only
o
Cooling / Heating with network or local auto changeover
o
On-Off electric reheat only
o
Cooling with On-Off or modulating Vdc pulsed electric reheat ( model dependent )
o
Heating with On-Off or modulating Vdc pulsed electric reheat ( model dependent )
o
Cooling / Heating with network or local changeover with On-Off or modulating Vdc pulsed electric reheat (
model dependent )
The VC3xxxX Relay Pack supplies power to the wall VTR73xxA Terminal Equipment Controller.
The VTR73xxA Controller operates the VC3xxxX Relay Pack(s) via a simple communication bus.
A maximum of 10 VC3xxxX Relay Pack can be used under a single VTR73xxA Terminal Equipment Controller.
3 wires minimum are required between the VTR73xxA Controller and
the first
VR7300 Relay Pack.
The 3 wire functions are as follow:
o
1 Tx / Rx Communication
o
2 Power Hot 7.0 Vdc 4 Watts maximum ( required for the VTR73xxA Controller power )
o
3 Power common
Commands for fan speed and valve operation are issued from the VTR73xxA Terminal Equipment Controller to the
VC3xxxX Relay Pack(s)
Typical one to one set-up
Existing or New Field VTR7300 Wires
3 minimum required 14-22 Ga
Solid or Stranded
H
C
High Voltage in cabinet wiring
- Line powered 90 to 277 Vac
- Line switching of fan & valves 90 to 277 Vac
- Isolated heating output for electric reheat
Line Voltage Power
Line Voltage Valves
- 2 pipes or 4 pipes applications
- Isolated line switching for electric reheat
Line Voltage Fan
- Configurable
- Up to 3 speed
fan control
- Auto fan speed
Local Inputs at VTR7300 Controller
Special optional local function(s):
- Remote motion detector(s)
- Window contacts
- Occupancy card holder
Model Dependent
Optional FCU Monitoring Inputs
- Service or Filter alarms
- Supply air sensor
- Return air sensor
- Changeover sensor or contact
Existing or New Communication Field Wires
- BACnet MS-TP
- LON TP-FT 10
- Wireless ( No wires )
