Viconics VBZS Application Guide - Manual (Page 10)

10
configuration.
• If the RTU is set to Control Type = Highest demand, the current action delivered by the RTU
will be heating.
• If the RTU is set to Control Type = Average of 3 Highest demand, the current action
delivered by the RTU will be cooling.
Example 3 with 5 voting master zones only
Voting
Zone 1
Voting
Zone 2
Voting
Zone 3
Voting
Zone 4
Voting
Zone 5
RTU Control Type
Current heat
demand
Current heat
demand
Current
heat
demand
Current
heat
demand
Current
heat
demand
Highest Average
of 3
highest
Average
of 5
highest
100% 0% 50%% 50% 0%
Heat weight
set
Heat weight
set
Heat
weight set
Heat
weight set
Heat
weight set
100% 100% 100% 50% 100%
Resulting
heat weight
to RTU
Resulting
heat weight
to RTU
Resulting
heat
weight to
RTU
Resulting
heat
weight to
RTU
Resulting
heat
weight to
RTU
100% 0% 50% 25% 0% 100% 58.3% 35%
Current cool
demand
Current cool
demand
Current
cool
demand
Current
cool
demand
Current
cool
demand
0% 100% 0% 0% 100%
Cool weight
set
Cool weight
set
Cool
weight set
Cool
weight set
Cool
weight set
100% 50% 50% 50% 75%
Resulting
cool weight
to RTU
Resulting
cool weight
to RTU
Resulting
cool
weight to
RTU
Resulting
cool
weight to
RTU
Resulting
cool
weight to
RTU
0% 50% 0% 0% 75% 75% 41.7.3% 25%
It can be seen here that the resulting demand used by the RTU controller for the five master voting
zones are different and will result in different heating action simply based on the RTU configuration.
Please note that the heating or cooling action delivered to the zones is also dependent on heating
and cooling lockout functions based on the outdoor and supply air temperature. Please see the next
section for more information.
2B) Overrides and User Zone Interface Lockouts
Each zone controller can have a function locked out for the local user. This can prevent unwanted inputs to
the system as a whole when the zone controllers are installed in public areas or when certain local user
interface functions of the zone controllers are to be prevented.
Lock level is access through the lockout configuration parameter. Please set the appropriate level for each
individual zone in the system according to their requirements.
VZ72xx Controller Lockout Level Configuration Value
0 1 2 3
Local occupied set point access using the Up and Down arrow keys Yes Yes Yes No
Pressing the local override key will command the local override function only,
However the local heating and cooling demands are not sent to the RTU
controller and the central system will not restart.
Typically used only when perimeter reheat is used and re-started during an
override period.
Pressing the override key allows an override for this zone controller only. Yes Yes No No
Pressing the local override key will command the local override function and Yes No No No