Viconics VTR7300 Application Manual - Manual (Page 3)

3
Operation overview
The VC3xxxX Series Line Voltage Switching Relay Pack(s) operate as slave unit(s) under the control of a single master
VTR73xxA Terminal Equipment Controller.
A) Each application below represents typical 3 speed FCU fan motor applications. 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.
B) Each application below represents 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 )
Operation Concept
ƒ The VC3xxxX Relay Pack supplies power to the wall VTR73xxA Terminal Equipment Controller.
ƒ The VTR73xxA Controller operates the VC3xxxX Relay Pack(s) via a simple communication bus.
ƒ A maximum of 10 VC3xxxX Relay Pack can be used under a single VTR73xxA Terminal Equipment Controller.
ƒ 3 wires minimum are required between the VTR73xxA Controller and the first VR7300 Relay Pack.
ƒ 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
ƒ Commands for fan speed and valve operation are issued from the VTR73xxA Terminal Equipment Controller to the
VC3xxxX Relay Pack(s)
ƒ FCU Remote inputs for monitoring and control. Remote inputs are read at the VC3xxxX Relay Pack ( models with
inputs only ). The present value of these inputs are read by the VTR73xxA Terminal Equipment Controller for it’s
internal operation
o RUI1 can be configured for:
ƒ None = no functions associated
ƒ COS = for a local 2 pipes system Change Over thermistor sensor
ƒ COC NO = for a local 2 pipes system Change Over Normally Opened dry contact thermostat
ƒ COC NC = for a local 2 pipes system Change Over Normally Closed dry contact thermostat
ƒ Service = A local and / or networked service alarm
ƒ Filter = A local and / or networked dirty filter alarm
o RBI2 can be configured for:
ƒ None = no functions associated
ƒ Service = A local and / or networked service alarm
ƒ Filter = A local and / or networked dirty filter alarm
o SS is dedicated to a discharge air sensor ( Auto Detect )
o RS is dedicated to a remote return air sensor ( Auto Detect )